@Proceedings{ DoddsFFHS2013, title = {Virtually face-to-face: Telecommunication and collaboration using Virtual Reality}, year = {2013}, month = {3}, pages = {-}, web_url = {http://ieeevr.org/2013/node/35}, publisher = {-}, address = {-}, event_name = {IEEE Virtual Reality 2013}, event_place = {Orlando, FL, USA}, state = {published}, ISBN = {-}, author = {Dodds T{dodds}{Department Human Perception, Cognition and Action}, Fr\"ohlich B, Fuchs H, Heldal I and Steptoe W} } @Article{ SoykaBB2013, title = {Temporal processing of self-motion: modeling reaction times for rotations and translations}, journal = {Experimental Brain Research}, year = {2013}, month = {7}, volume = {228}, number = {1}, pages = {51-62}, abstract = {In this paper, we show that differences in reaction times (RT) to self-motion depend not only on the duration of the profile, but also on the actual time course of the acceleration. We previously proposed models that described direction discrimination thresholds for rotational and translational motions based on the dynamics of the vestibular sensory organs (otoliths and semi-circular canals). As these models have the potential to describe RT for different motion profiles (e.g., trapezoidal versus triangular acceleration profiles or varying profile durations), we validated these models by measuring RTs in human observers for a direction discrimination task using both translational and rotational motions varying in amplitude, duration and acceleration profile shape in a within-subjects design. In agreement with previous studies, amplitude and duration were found to affect RT, and importantly, we found an influence of the profile shape on RT. The models are able to fit the measured RTs with an accuracy of around 5 ms, and the best-fitting parameters are similar to those found from identifying the models based on threshold measurements. This confirms the validity of the modeling approach and links perceptual thresholds to RT. By establishing a link between vestibular thresholds for self-motion and RT, we show for the first time that RTs to purely inertial motion stimuli can be used as an alternative to threshold measurements for identifying self-motion perception models. This is advantageous, since RT tasks are less challenging for participants and make assessment of vestibular function less fatiguing. Further, our results provide strong evidence that the perceived timing of self-motion stimulation is largely influenced by the response dynamics of the vestibular sensory organs.}, web_url = {http://link.springer.com/content/pdf/10.1007%2Fs00221-013-3536-y.pdf}, state = {published}, DOI = {10.1007/s00221-013-3536-y}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}} } @Article{ EngelC2013, title = {Detectability Prediction for Increased Scene Awareness}, journal = {IEEE Intelligent Transportation Systems Magazine}, year = {2013}, month = {6}, state = {accepted}, author = {Engel D{engel}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Article{ BonevCE2012, title = {How do image complexity, task demands and looking biases influence human gaze behavior?}, journal = {Pattern Recognition Letters}, year = {2013}, month = {5}, volume = {34}, number = {7}, pages = {723–730}, abstract = {In this paper we propose an information-theoretic approach to understand eye-movement patterns, in relation to the task performed and image complexity. We commence with the analysis of the distributions and amplitudes of eye-movement saccades, performed across two different image-viewing tasks: free viewing and visual search. Our working hypothesis is that the complexity of image information and task demands should interact. This should be reflected in the Markovian pattern of short and long saccades. We compute high-order Markovian models of performing a large saccade after many short ones and also propose a novel method for quantifying image complexity. The analysis of the interaction between high-order Markovianity, task and image complexity supports our hypothesis.}, web_url = {http://www.sciencedirect.com/science/article/pii/S0167865512001687}, state = {published}, DOI = {10.1016/j.patrec.2012.05.007}, author = {Bonev B, Chuang LL{chuang}{Department Human Perception, Cognition and Action} and Escolano F} } @Article{ QuarantaMV2013, title = {Impact of pilots’ biodynamic feedthrough on rotorcraft by robust stability}, journal = {Journal of Sound and Vibration}, year = {2013}, month = {5}, volume = {Epub ahead}, abstract = {The coupling of rotorcraft dynamics with the dynamics of one of the main systems devoted to its control, the pilot, may lead to several peculiar phenomena, known as Rotorcraft–Pilot Couplings (RPCs), all characterized by an abnormal behavior that may jeopardize flight safety. Among these phenomena, there is a special class of couplings which is dominated by the biodynamic behavior of the pilot's limbs that close the loop between the vibrations and the control inceptors in the cockpit. Leveraging robust stability analysis, the inherently uncertain pilot biodynamics can be treated as the uncertain portion of a feedback system, making analytical, numerical or graphical determination of proneness to RPC possible by comparing robust stability margins of helicopter models with experimental Biodynamic Feedthrough (BDFT) data. The application of the proposed approach to collective bounce is exemplified using simple analytical helicopter and pilot models. The approach is also applied to detailed helicopter models and experimental BDFT measurement data.}, web_url = {http://www.sciencedirect.com/science/article/pii/S0022460X13003581}, state = {published}, DOI = {10.1016/j.jsv.2013.04.020}, author = {Quaranta G, Masarati P and Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}} } @Article{ NieuwenhuizenMvB2013, title = {Influences of Simulator Motion System Characteristics on Pilot Control Behavior}, journal = {Journal of Guidance, Control, and Dynamics}, year = {2013}, month = {5}, volume = {36}, number = {3}, pages = {667-676}, abstract = {Low-cost motion systems have been proposed for certain training tasks that would otherwise be performed on highperformance full-flight simulators. These systems usually have lower bandwidth and lower smoothness. The influence of these characteristics on pilot perception and control behavior is unknown and needs to be investigated. In this paper, this is done by simulating a model of a simulator with limited capabilities on a high-end simulator. The platform limitations, which consist of a platform filter, time delay, and noise characteristics, can then be removed one by one, and their effect on control behavior is studied in isolation. An experiment was conducted to identify pilot perception and control behavior in a closed-loop control task. The time delay and noise characteristics of the simulators did not have an effect. However, it was found that the bandwidth of the motion system had a significant effect on performance and control behavior. Results indicate that the motion cues were barely used at all in conditions with a low bandwidth, and that participants relied on the visual cues to generate lead to perform the control task.}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/1.59257}, state = {published}, DOI = {10.2514/1.59257}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, Mulder M, van Paassen MM and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ WallravenWB2013, title = {Learning to recognize face shapes through serial exploration}, journal = {Experimental Brain Research}, year = {2013}, month = {5}, volume = {226}, number = {4}, pages = {513-523}, abstract = {Human observers are experts at visual face recognition due to specialized visual mechanisms for face processing that evolve with perceptual expertize. Such expertize has long been attributed to the use of configural processing, enabled by fast, parallel information encoding of the visual information in the face. Here we tested whether participants can learn to efficiently recognize faces that are serially encoded—that is, when only partial visual information about the face is available at any given time. For this, ten participants were trained in gaze-restricted face recognition in which face masks were viewed through a small aperture controlled by the participant. Tests comparing trained with untrained performance revealed (1) a marked improvement in terms of speed and accuracy, (2) a gradual development of configural processing strategies, and (3) participants’ ability to rapidly learn and accurately recognize novel exemplars. This performance pattern demonstrates that participants were able to learn new strategies to compensate for the serial nature of information encoding. The results are discussed in terms of expertize acquisition and relevance for other sensory modalities relying on serial encoding.}, web_url = {http://link.springer.com/content/pdf/10.1007%2Fs00221-013-3463-y.pdf}, state = {published}, DOI = {10.1007/s00221-013-3463-y}, author = {Wallraven C{walli}{Department Human Perception, Cognition and Action}, Whittingstall L{ldopjans}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ BerthozBBCFFHKMMNPRSSTVvVW2013, title = {Motion Scaling for High-Performance Driving Simulators}, journal = {IEEE Transactions on Human-Machine Systems}, year = {2013}, month = {5}, volume = {43}, number = {3}, pages = {265-276}, abstract = {Advanced driving simulators aim at rendering the motion of a vehicle with maximum fidelity, which requires increased mechanical travel, size, and cost of the system. Motion cueing algorithms reduce the motion envelope by taking advantage of limitations in human motion perception, and the most commonly employed method is just to scale down the physical motion. However, little is known on the effects of motion scaling on motion perception and on actual driving performance. This paper presents the results of a European collaborative project, which explored different motion scale factors in a slalom driving task. Three state-of-the-art simulator systems were used, which were capable of generating displacements of several meters. The results of four comparable driving experiments, which were obtained with a total of 65 participants, indicate a preference for motion scale factors below 1, within a wide range of acceptable values (0.4–0.75). Very reduced or absent motion cues significantly degrade driving performance. Applications of this research are discussed for the design of motion systems and cueing algorithms for driving simulation.}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6502304}, state = {published}, DOI = {10.1109/TSMC.2013.2242885}, author = {Berthoz A, Bles W, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Correia Gracio BJ, Feenstra P, Filliard N, Huhne R, Kemeny A, Mayrhofer M, Mulder M, Nusseck HG{nusseck}{Department Human Perception, Cognition and Action}, Pretto P{pretto}{Department Human Perception, Cognition and Action}, Reymond G, Schl\"usselberger R, Schwandtner J, Teufel H, Vailleau B, van Paassen MM, Vidal M{vidal}{Department Human Perception, Cognition and Action} and Wentink M} } @Article{ SchultzBBP2012, title = {What the Human Brain Likes About Facial Motion}, journal = {Cerebral Cortex}, year = {2013}, month = {5}, volume = {23}, number = {5}, pages = {1167-1178}, abstract = {Facial motion carries essential information about other people's emotions and intentions. Most previous studies have suggested that facial motion is mainly processed in the superior temporal sulcus (STS), but several recent studies have also shown involvement of ventral temporal face-sensitive regions. Up to now, it is not known whether the increased response to facial motion is due to an increased amount of static information in the stimulus, to the deformation of the face over time, or to increased attentional demands. We presented nonrigidly moving faces and control stimuli to participants performing a demanding task unrelated to the face stimuli. We manipulated the amount of static information by using movies with different frame rates. The fluidity of the motion was manipulated by presenting movies with frames either in the order in which they were recorded or in scrambled order. Results confirm higher activation for moving compared with static faces in STS and under certain conditions in ventral temporal face-sensitive regions. Activation was maximal at a frame rate of 12.5 Hz and smaller for scrambled movies. These results indicate that both the amount of static information and the fluid facial motion per se are important factors for the processing of dynamic faces.}, file_url = {fileadmin/user_upload/files/publications/2012/Cerebral-Cortex-2012-Schultz.pdf}, web_url = {http://cercor.oxfordjournals.org/content/23/5/1167.full.pdf+html}, state = {published}, DOI = {10.1093/cercor/bhs106}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action}, Brockhaus M{mabrockhaus}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Pilz K{kpilz}{Department Human Perception, Cognition and Action}} } @Article{ delaRosaB2013, title = {Motor-visual neurons and action recognition in social interactions. Commentary on Mirror neurons: From origin to function}, journal = {Behavioral and Brain Sciences}, year = {2013}, month = {5}, state = {accepted}, author = {de la Rosa S{delarosa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ FranchiOS2013, title = {Mutual Localization in Multi-Robot Systems using Anonymous Relative Measurements}, journal = {International Journal of Robotics Research}, year = {2013}, month = {5}, abstract = {We propose a decentralized method to perform mutual localization in multi-robot systems using anonymous relative measurements, i.e., measurements that do not include the identity of the measured robot. This is a challenging and practically relevant operating scenario that has received little attention in the literature. Our mutual localization algorithm includes two main components: a probabilistic multiple registration stage, which provides all data associations that are consistent with the relative robot measurements and the current belief, and a dynamic filtering stage, which incorporates odometric data into the estimation process. The design of the proposed method proceeds from a detailed formal analysis of the implications of anonymity on the mutual localization problem. Experimental results on a team of differential-drive robots illustrate the effectiveness of the approach, and in particular its robustness against false positives and negatives that may affect the robot measurement process. We also provide an experimental comparison that shows how the proposed method outperforms more classical approaches that may be designed building on existing techniques. The source code of the proposed method is available within the MLAM ROS stack.}, file_url = {fileadmin/user_upload/files/publications/2013/2013g-FraOriSte.pdf}, state = {accepted}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}, Oriolo G and Stegagno P} } @Article{ LeeFSBR2013, title = {Semi-Autonomous Haptic Teleoperation Control Architecture of Multiple Unmanned Aerial Vehicles}, journal = {IEEE/ASME Transaction on Mechatronics}, year = {2013}, month = {5}, abstract = {Abstract—We propose a novel semi-autonomous haptic teleoperation control architecture for multiple unmanned aerial vehicles (UAVs), consisting of three control layers: 1) UAV control layer, where each UAV is abstracted by, and is controlled to follow the trajectory of, its own kinematic Cartesian virtual point (VP); 2) VP control layer, which modulates each VP’s motion according to the teleoperation commands and local artificial potentials (for VP-VP/VP-obstacle collision avoidance and VP-VP connectivity preservation); and 3) teleoperation layer, through which a single remote human user can command all (or some) of the VPs’ velocity while haptically perceiving the state of all (or some) of the UAVs and obstacles. Master-passivity/slave-stability and some asymptotic performance measures are proved. Experimental results using four custom-built quadrotor-type UAVs are also presented to illustrate the theory.}, file_url = {fileadmin/user_upload/files/publications/2013/2013b-LeeFraSonBueRob.pdf}, state = {accepted}, author = {Lee D, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Son HI{chakurt}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Article{ PiryankovadKBM2013, title = {Egocentric distance perception in large screen immersive displays}, journal = {Displays}, year = {2013}, month = {4}, volume = {34}, number = {2}, pages = {153–164}, abstract = {Many scientists have demonstrated that compared to the real world egocentric distances in head-mounted display virtual environments are underestimated. However, distance perception in large screen immersive displays has received less attention. We investigate egocentric distance perception in a virtual office room projected using a semi-spherical, a Max Planck Institute CyberMotion Simulator cabin and a flat large screen immersive display. The goal of our research is to systematically investigate distance perception in large screen immersive displays with commonly used technical specifications. We specifically investigate the role of distance to the target, stereoscopic projection and motion parallax on distance perception. We use verbal reports and blind walking as response measures for the real world experiment. Due to the limited space in the three large screen immersive displays we use only verbal reports as the response measure for the experiments in the virtual environment. Our results show an overall underestimation of distance perception in the large screen immersive displays, while verbal estimates of distances are nearly veridical in the real world. We find that even when providing motion parallax and stereoscopic depth cues to the observer in the flat large screen immersive display, participants estimate the distances to be smaller than intended. Although stereo cues in the flat large screen immersive display do increase distance estimates for the nearest distance, the impact of the stereoscopic depth cues is not enough to result in veridical distance perception. Further, we demonstrate that the distance to the target significantly influences the percent error of verbal estimates in both the real and virtual world. The impact of the distance to the target on the distance judgments is the same in the real world and in two of the used large screen displays, namely, the MPI CyberMotion Simulator cabin and the flat displays. However, in the semi-spherical display we observe a significantly different influence of distance to the target on verbal estimates of egocentric distances. Finally, we discuss potential reasons for our results. Based on the findings from our research we give general suggestions that could serve as methods for improving the LSIDs in terms of the accuracy of depth perception and suggest methods to compensate for the underestimation of verbal distance estimates in large screen immersive displays.}, web_url = {http://www.sciencedirect.com/science/article/pii/S0141938213000036}, state = {published}, DOI = {10.1016/j.displa.2013.01.001}, author = {Piryankova IV{ivelina}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Kloos U, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Article{ SonFLKBR2012, title = {Human-Centered Design and Evaluation of Haptic Cueing for Teleoperation of Multiple Mobile Robots}, journal = {IEEE Transactions on Cybernetics}, year = {2013}, month = {4}, volume = {43}, number = {2}, pages = {597-609}, abstract = {In this paper, we investigate the effect of haptic cueing on a human operator's performance in the field of bilateral teleoperation of multiple mobile robots, particularly multiple unmanned aerial vehicles (UAVs). Two aspects of human performance are deemed important in this area, namely, the maneuverability of mobile robots and the perceptual sensitivity of the remote environment. We introduce metrics that allow us to address these aspects in two psychophysical studies, which are reported here. Three fundamental haptic cue types were evaluated. The Force cue conveys information on the proximity of the commanded trajectory to obstacles in the remote environment. The Velocity cue represents the mismatch between the commanded and actual velocities of the UAVs and can implicitly provide a rich amount of information regarding the actual behavior of the UAVs. Finally, the Velocity+Force cue is a linear combination of the two. Our experimental results show that, while maneuverability is best supported by the Force cue feedback, perceptual sensitivity is best served by the Velocity cue feedback. In addition, we show that large gains in the haptic feedbacks do not always guarantee an enhancement in the teleoperator's performance.}, file_url = {fileadmin/user_upload/files/publications/2012/2013a-SonFraChuKimBueRob.pdf}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6294459}, state = {published}, DOI = {10.1109/TSMCB.2012.2212884}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Chuang LL{chuang}{Department Human Perception, Cognition and Action}, Kim J{junsukkim}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Article{ ZaalNvM2013, title = {Modeling Human Control of Self-Motion Direction With Optic Flow and Vestibular Motion}, journal = {IEEE Transactions on Cybernetics}, year = {2013}, month = {4}, volume = {43}, number = {2}, pages = {544-556}, abstract = {In this paper, we investigate the effects of visual and motion stimuli on the manual control of one's direction of self-motion. In a flight simulator, subjects conducted an active target-following disturbance-rejection task, using a compensatory display. Simulating a vehicular control task, the direction of vehicular motion was shown on the outside visual display in two ways: an explicit presentation using a symbol and an implicit presentation, namely, through the focus of radial outflow that emerges from optic flow. In addition, the effects of the relative strength of congruent vestibular motion cues were investigated. The dynamic properties of human visual and vestibular motion perception paths were modeled using a control-theoretical approach. As expected, improved tracking performance was found for the configurations that explicitly showed the direction of self-motion. The human visual time delay increased with approximately 150 ms for the optic flow conditions, relative to explicit presentations. Vestibular motion, providing higher order information on the direction of self-motion, allowed subjects to partially compensate for this visual perception delay, improving performance. Parameter estimates of the operator control model show that, with vestibular motion, the visual feedback becomes stronger, indicating that operators are more confident to act on optic flow information when congruent vestibular motion cues are present.}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6298973}, state = {published}, DOI = {10.1109/TSMCB.2012.2212188}, author = {Zaal PMT, Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, van Paassen MM and Mulder M} } @Article{ CensiFMO2012, title = {Simultaneous Calibration of Odometry and Sensor Parameters for Mobile Robots}, journal = {IEEE Transaction on Robotics}, year = {2013}, month = {4}, volume = {29}, number = {2}, pages = {475-492}, abstract = {Consider a differential-drive mobile robot equipped with an on-board exteroceptive sensor that can estimate its own motion, e.g., a range-finder. Calibration of this robot involves estimating six parameters: three for the odometry (radii and distance between the wheels) and three for the pose of the sensor with respect to the robot. After analyzing the observability of this problem, this paper describes a method for calibrating all parameters at the same time, without the need for external sensors or devices, using only the measurement of the wheel velocities and the data from the exteroceptive sensor. The method does not require the robot to move along particular trajectories. Simultaneous calibration is formulated as a maximum-likelihood problem and the solution is found in a closed form. Experimental results show that the accuracy of the proposed calibration method is very close to the attainable limit given by the Cramér-Rao bound.}, file_url = {fileadmin/user_upload/files/publications/2012/2013i-CenFraMarOri.pdf}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6482657}, state = {published}, DOI = {10.1109/TRO.2012.2226380}, author = {Censi A, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Marchionni L and Oriolo G} } @Article{ RobuffoGiordanoFSB2012, title = {A Passivity-Based Decentralized Strategy for Generalized Connectivity Maintenance}, journal = {International Journal of Robotics Research}, year = {2013}, month = {3}, volume = {32}, number = {3}, pages = {299-323}, abstract = {The design of decentralized controllers coping with the typical constraints on the inter-robot sensing/communication capabilities represents a promising direction in multi-robot research thanks to the inherent scalability and fault tolerance of these approaches. In these cases, connectivity of the underlying interaction graph plays a fundamental role: it represents a necessary condition for allowing a group or robots to achieve a common task by resorting to only local information. The goal of this paper is to present a novel decentralized strategy able to enforce connectivity maintenance for a group of robots in a flexible way, that is, by granting large freedom to the group internal configuration so as to allow establishment/deletion of interaction links at anytime as long as global connectivity is preserved. A peculiar feature of our approach is that we are able to embed into a unique connectivity preserving action a large number of constraints and requirements for the group: (i) the presence of specific inter-robot sensing/communication models; (ii) group requirements such as formation control; and (iii) individual requirements such as collision avoidance. This is achieved by defining a suitable global potential function of the second smallest eigenvalue λ2 of the graph Laplacian, and by computing, in a decentralized way, a gradient-like controller built on top of this potential. Simulation results obtained with a group of quadrotor unmanned aerial vehicles (UAVs) and unmanned ground vehicles, and experimental results obtained with four quadrotor UAVs, are finally presented to thoroughly illustrate the features of our approach on a concrete case study.}, file_url = {fileadmin/user_upload/files/publications/2013/2013l-RobFraSecBue-preprint.pdf}, web_url = {http://ijr.sagepub.com/content/32/3/299.full.pdf+html}, state = {published}, DOI = {10.1177/0278364912469671}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Secchi C and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ KimKLKLCLPC2013, title = {Development and Validation of Acupuncture Fear Scale}, journal = {Evidence-Based Complementary and Alternative Medicine}, year = {2013}, month = {3}, volume = {2013}, pages = {1-8}, abstract = {Objectives. Strong aversions to acupuncture have been an obstacle to understanding its intrinsic action of acupuncture. Thus, it is necessary to evaluate the nature and extent of fear of acupuncture treatment. Our study aims to develop and validate an instrument that evaluates a patient’s fear of acupuncture treatment. Methods. We have developed an acupuncture fear scale, a 16-item instrument which assesses the acupuncture fear score and uses it to survey 275 participants in South Korea, thus testing the reliability and validity of the instrument. Results. Internal consistency was high (Cronbach’s alpha = 0.935). Test-retest reliability (Spearman’s rank correlation coefficient) among 33 participants out of 275 ranged from 0.565 to 0.797 (P < 0.001). Principal component analysis revealed two factors accounting for 68% of the variance, which are painful sensation and possible adverse events, respectively. The acupuncture fear scale was positively correlated with the total of fear of pain questionnaire-III (r = 0.423, P < 0.001). Conclusions. The acupuncture fear scale can be a valid and reliable instrument that can measure fear of acupuncture treatment. These results strongly suggest that it would be a clinically useful tool to assess fear of acupuncture in the acupuncture clinic setting and an important instrument to understand the complex social-behavioral component of acupuncture modality.}, web_url = {http://downloads.hindawi.com/journals/ecam/2013/109704.pdf}, state = {published}, DOI = {10.1155/2013/109704}, EPUB = {109704}, author = {Kim H-S, Kim Y-J, Lee H-J, Kim S-Y, Lee H, Chang D-S{dong}{Department Human Perception, Cognition and Action}, Lee H, Park H-J and Chae Y} } @Article{ ChoSBLL2011, title = {Gain-Scheduling Control of Teleoperation Systems Interacting With Soft Tissues}, journal = {IEEE Transactions on Industrial Electronics}, year = {2013}, month = {3}, volume = {60}, number = {3}, pages = {946-957}, abstract = {Surgical teleoperation systems are being increasingly deployed recently. There are, however, some unsolved issues such as nonlinear characteristics of the interaction between the slave robot and soft tissues, and difficulty in employing force sensors in the surgical end-effectors of the slave. These issues make it difficult to generalize any approach to develop a control for the system. This paper addresses these issues by proposing a H1 suboptimal controller preserving robust stability and performance. The environment, i.e., soft tissues, is characterized with the nonlinear Hunt-Crossley model. This nonlinear characteristics of soft tissues are expressed with an affine combination of linear models within a predefined parameter polytope. For this linear parmeter varying system, a gain-scheduling control scheme is employed to design a sub-optimal controller while guaranteeing its stability. To avoid using any force measurement in slave, we used position-position control architecture. The developed gain-scheduling control is validated with quantitative experimental results. The developed gain-scheduling PP control scheme shows good tracking capacity and high transparency for varied experimental conditions. Error of the transmitted impedance is significantly lower compared to other conventional control schemes for frequencies less than 2Hz which is frequently recommended for surgical teleoperation.}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6161639}, state = {published}, DOI = {10.1109/TIE.2012.2189537}, author = {Cho JH, Son HI{chakurt}{Department Human Perception, Cognition and Action}, Bhattacharjee T, Lee DG and Lee DY} } @Article{ ChangKLLLPWC2013, title = {Modifying Bodily Self-Awareness during Acupuncture Needle Stimulation Using the Rubber Hand Illusion}, journal = {Evidence-Based Complementary and Alternative Medicine}, year = {2013}, month = {3}, volume = {2013}, pages = {1-7}, abstract = {Background. The rubber hand illusion (RHI) is an experimental paradigm that manipulates important aspects of body self-awareness. Objectives. We were interested in whether modifying bodily self-awareness by manipulation of body ownership and visual expectations using the RHI would change the subjective perception of pain as well as the autonomic response to acupuncture needle stimulation. Methods. Acupuncture needle stimulation was applied to the real hand during the RHI with (experiment 1) or without (experiment 2) visual expectation while measuring concurrent autonomic changes such as the skin conductance response (SCR). Subjective responses such as perception of the RHI and perceived pain were measured by questionnaires. Results. In experiment 1, the amplitude of the increase in SCR was visibly higher during the synchronous session compared with that of the asynchronous session. In experiment 2, the amplitude of the increase of SCR was lower for the synchronous session compared with that for the asynchronous session. Comparing these two experiments, the visual expectation of needle stimulation produced a greater autonomic response to acupuncture stimulation. Conclusions. Our findings suggest that the sympathetic response to acupuncture needle stimulation is primarily influenced by visual expectation rather than by modifications of body ownership.}, web_url = {http://downloads.hindawi.com/journals/ecam/2013/849602.pdf}, state = {published}, DOI = {10.1155/2013/849602}, EPUB = {849602}, author = {Chang D-S{dong}{Department Human Perception, Cognition and Action}, Kim Y-J, Lee S-H, Lee H, Lee I-S, Park H-J, Wallraven C{walli}{Department Human Perception, Cognition and Action} and Chae Y} } @Article{ deLucaMRUSvKv2012, title = {Motion Control of the CyberCarpet Platform}, journal = {IEEE Transactions on Control Systems Technology}, year = {2013}, month = {3}, volume = {21}, number = {2}, pages = {410-427}, abstract = {The CyberCarpet is an actuated platform that allows unconstrained locomotion of a walking user for Virtual Reality exploration. The platform consists of a linear treadmill covered by a ball-array carpet and mounted on a turntable, and is equipped with two actuating devices for linear and angular motion. The main control objective is to keep the walker close to the platform center in the most natural way, counteracting his/her voluntary motion while satisfying perceptual constraints. The motion control problem for this platform is not trivial since the system kinematics is subject to a nonholonomic constraint. In the first part of the paper we describe the kinematic control design devised within the CyberWalk project, where the linear and angular platform velocities are used as input commands and feedback is based only on walker's position measurements obtained by an external visual tracking system. In particular, we present a globally stabilizing control scheme that combines a feedback and a feedforward action, based on a disturbance observer of the walker's intentional velocity. We also discuss possible extensions to acceleration-level control and the related assessment of dynamic issues affecting a walker during his/her motion. The second part of the paper is devoted to the actual implementation of the overall system. As a proof of concept of a final full-scale platform, the mechanical design and realization of a small-scale prototype of the CyberCarpet is presented, as well as the visual localization method used to obtain the human walker's position on the platform by an overhead camera. To validate the proposed motion control design, experimental results are reported and discussed for a series of motion tasks performed using a small tracked vehicle representative of a moving user.}, file_url = {fileadmin/user_upload/files/publications/2012/CyberCarpet_TCST_2011-0582.pdf}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6146383}, state = {published}, DOI = {10.1109/TCST.2012.2185051}, author = {De Luca A, Mattone R, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Ulbrich H, Schwaiger M, van Bergh M, Koller-Meier E and van Gool L} } @Article{ OrtegaB2013, title = {Thermodynamics as a theory of decision-making with information-processing costs}, journal = {Proceedings of the Royal Society of London A}, year = {2013}, month = {3}, volume = {Epub ahead}, abstract = {Perfectly rational decision-makers maximize expected utility, but crucially ignore the resource costs incurred when determining optimal actions. Here, we propose a thermodynamically inspired formalization of bounded rational decision-making where information processing is modelled as state changes in thermodynamic systems that can be quantified by differences in free energy. By optimizing a free energy, bounded rational decision-makers trade off expected utility gains and information-processing costs measured by the relative entropy. As a result, the bounded rational decision-making problem can be rephrased in terms of well-known variational principles from statistical physics. In the limit when computational costs are ignored, the maximum expected utility principle is recovered. We discuss links to existing decision-making frameworks and applications to human decision-making experiments that are at odds with expected utility theory. Since most of the mathematical machinery can be borrowed from statistical physics, the main contribution is to re-interpret the formalism of thermodynamic free-energy differences in terms of bounded rational decision-making and to discuss its relationship to human decision-making experiments.}, web_url = {http://rspa.royalsocietypublishing.org/content/469/2153/20120683.short}, state = {published}, DOI = {10.1098/rspa.2012.0683}, author = {Ortega PA{portega}{Research Group Sensorimotor Learning and Decision-Making} and Braun DA{dbraun}{Research Group Sensorimotor Learning and Decision-Making}} } @Article{ WallravenD2013, title = {Visual experience is necessary for efficient haptic face recognition}, journal = {NeuroReport}, year = {2013}, month = {3}, volume = {24}, number = {5}, pages = {254–258}, abstract = {Humans are experts for face processing - this expertise develops over the course of several years, given visual input about faces from infancy. Recent studies have shown that individuals can also recognize faces haptically, albeit at lower performance than visually. Given that blind individuals are extensively trained on haptic processing, one may expect them to perform better at recognizing faces from touch than sighted individuals. Here, we tested this hypothesis using matched groups of sighted, congenitally blind, and acquired-blind individuals. Surprisingly, we found little evidence for a performance benefit for blind participants compared with sighted controls. Moreover, the congenitally blind group performed significantly worse than both the sighted and the acquired-blind group. Our results are consistent with the hypothesis that visual expertise may be necessary for haptic face recognition; hence, even extensive haptic training cannot easily account for deficits in visual processing.}, state = {published}, DOI = {10.1097/WNR.0b013e32835f00c0}, author = {Wallraven C{walli}{Department Human Perception, Cognition and Action} and Dopjans L{ldopjans}{Department Human Perception, Cognition and Action}} } @Article{ RuddleVB2013, title = {Learning to Walk in Virtual Reality}, journal = {ACM Transactions on Applied Perception}, year = {2013}, month = {3}, abstract = {This article provides longitudinal data for when participants learned to travel with a walking metaphor through virtual reality (VR) worlds, using interfaces that ranged from joystick-only, to linear and omnidirectional treadmills, and actual walking in VR. Three metrics were used: travel time, collisions (a measure of accuracy), and the speed profile. The time that participants required to reach asymptotic performance for traveling, and what that asymptote was, varied considerably between interfaces. In particular, when a world had tight turns (0.75 m corridors), participants who walked were more proficient than those who used a joystick to locomote and turned either physically or with a joystick, even after 10 minutes of training. The speed profile showed that this was caused by participants spending a notable percentage of the time stationary, irrespective of whether or not they frequently played computer games. The study shows how speed profiles can be used to help evaluate participants‟ proficiency with travel interfaces, highlights the need for training to be structured to addresses specific weaknesses in proficiency (e.g., start-stop movement), and for studies to measure and report that proficiency.}, file_url = {fileadmin/user_upload/files/publications/2013/ruddle-acm-tap.pdf}, state = {accepted}, author = {Ruddle RA{roy}, Volkova E{evolk}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ VenrooijMAvvB2012, title = {A New View on Biodynamic Feedthrough Analysis: Unifying the Effects on Forces and Positions}, journal = {IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics}, year = {2013}, month = {2}, volume = {43}, number = {1}, pages = {129-142}, abstract = {When performing a manual control task, vehicle accelerations can cause involuntary limb motions, which can result in unintentional control inputs. This phenomenon is called biodynamic feedthrough (BDFT). In the past decades, many studies into BDFT have been performed, but its fundamentals are still only poorly understood. What has become clear, though, is that BDFT is a highly complex process, and its occurrence is influenced by many different factors. A particularly challenging topic in BDFT research is the role of the human operator, which is not only a very complex but also a highly adaptive system. In literature, two different ways of measuring and analyzing BDFT are reported. One considers the transfer of accelerations to involuntary forces applied to the control device (CD); the other considers the transfer of accelerations to involuntary CD deflections or positions. The goal of this paper is to describe an approach to unify these two methods. It will be shown how the results of the two methods relate and how this knowledge may aid in understanding BDFT better as a whole. The approach presented is based on the notion that BDFT dynamics can be described by the combination of two transfer dynamics: 1) the transfer dynamics from body accelerations to involuntary forces and 2) the transfer dynamics from forces to CD deflections. The approach was validated using experimental results.}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6225447}, state = {published}, DOI = {10.1109/TSMCB.2012.2200972}, author = {Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}, Mulder M, Abbink DA, van Paassen MM, van der Helm FCT and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ DropPDVM2012, title = {Identification of the Feedforward Component of Manual Control in Tasks with Predictable Target Signals}, journal = {IEEE Transactions on Cybernetics}, year = {2013}, month = {2}, volume = {Epub ahead}, pages = {1-14}, abstract = {In the manual control of a dynamic system, the human controller (HC) often follows a visible and predictable reference path. Compared with a purely feedback control strategy, performance can be improved by making use of this knowledge of the reference. The operator could effectively introduce feedforward control in conjunction with a feedback path to compensate for errors, as hypothesized in literature. However, feedforward behavior has never been identified from experimental data, nor have the hypothesized models been validated. This paper investigates human control behavior in pursuit tracking of a predictable reference signal while being perturbed by a quasi-random multisine disturbance signal. An experiment was done in which the relative strength of the target and disturbance signals were systematically varied. The anticipated changes in control behavior were studied by means of an ARX model analysis and by fitting three parametric HC models: two different feedback models and a combined feedforward and feedback model. The ARX analysis shows that the experiment participants employed control action on both the error and the target signal. The control action on the target was similar to the inverse of the system dynamics. Model fits show that this behavior can be modeled best by the combined feedforward and feedback model.}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6425447}, state = {published}, DOI = {10.1109/TSMCB.2012.2235829}, author = {Drop FM{fdrop}{Department Human Perception, Cognition and Action}, Pool DM{dpool}{Department Human Perception, Cognition and Action}, Damveld HJ, van Paassen MM and Mulder M} } @Article{ HuberleL2013, title = {Temporal properties of shape processing by event-related MEG adaptation}, journal = {NeuroImage}, year = {2013}, month = {2}, volume = {67}, pages = {119–126}, abstract = {Object recognition is a fundamental mechanism of visual processing and requires the extraction of shape information. Early visual areas have been linked to the analysis of local image features, while higher visual areas of the ventral visual pathway rather mediate the perception and recognition of global shapes. Investigations of the spatiotemporal characteristics of shape analysis in the human visual cortex by rapid event-related fMRI adaptation in combination with a region of interest analysis suggested a transient manner of contour integration and shape processing in early visual areas compared to sustained processing in higher visual areas. fMRI adaptation (or repetition suppression) paradigms offer the possibility to enhance the restricted spatial resolution of conventional fMRI by focusing on decreased responses for repeated stimulus presentation. However, improving our understanding of complex neuronal mechanisms in the human brain requires the investigation not only at high spatial but also temporal resolution. A limitation of fMRI adaptation can be found in its poor temporal resolution which EEG- and MEG-techniques can overcome, though at a lower spatial resolution. The present study aimed to investigate temporal characteristics of shape processing in the human brain by adapting the principles of fMRI adaption in a MEG study. In parallel to an earlier fMRI study, the two stimuli of a trial were presented at varied interstimulus intervals. Additional analyses by means of a dipole analysis and co-registration of MEG and fMRI data were conducted. Adaptation was observed for the short as well as the longer interstimulus interval. Interestingly, the latency of the adaptation effects varied with the interstimulus interval. The findings support a late onset of adaption that possibly underlies global discrimination processes and recognition in higher areas of the ventral visual pathway. Further, the present results indicate a useful extension of adaptation paradigms and ‘region of interest’-analyses from fMRI to MEG at a high temporal resolution.}, web_url = {http://www.sciencedirect.com/science/article/pii/S1053811912010749}, state = {published}, DOI = {10.1016/j.neuroimage.2012.10.070}, author = {Huberle E{elli}{Department Human Perception, Cognition and Action} and Lutzenberger W} } @Article{ NieuwenhuizenvSMB2012, title = {Cross-platform Validation for a Model of a Low-cost Stewart Platform}, journal = {Journal of Modeling, Simulation, Identification, and Control}, year = {2013}, month = {1}, volume = {1}, number = {1}, pages = {1-23}, abstract = {actuators, lower bandwidth, and higher motion noise. The influence of these characteristics on pilot perception and control behavior is unknown, and needs to be investigated. A possible approach to this would be to simulate a platform with limited capabilities with a high-end platform, and then remove the platform limitations one by one. The effects of these platform limitations on pilot behavior can then be investigated in isolation. In this paper, a model of a low-cost simulator was validated for simulation on a high-performance simulator. A dynamic model of the MPI Stewart platform was analyzed and compared with measurements of the baseline simulator response. Measurements for validation of the implementation of the model on the SIMONA Research Simulator showed that the dynamics of the MPI Stewart platform could be represented well in terms of dynamic range, time}, web_url = {http://uscip.org/JournalsDetail.aspx?journalID=21}, state = {published}, DOI = {10.7726/jmsic.2013.1001}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, van Paassen MM, Stroosma O, Mulder M and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ ZhaoH2013, title = {Integrative processing of invariant aspects of faces: Effect of gender and race processing on identity analysis}, journal = {Journal of Vision}, year = {2013}, month = {1}, volume = {13}, number = {1:15}, pages = {1-18}, abstract = {While separation of face identity and expression processing is favored by many face perception models, how the visual system analyzes identity and other face properties remains elusive. Here we investigated whether identity analysis is independent of or influenced by automatic processing of face gender and race. Participants searched for a target face among distractor faces whose gender or race was either the same as or different from the target face. Visual search was faster and more accurate when target and distractor faces differed in gender or race property than when not. The effect persisted for identification of both familiar and novel faces, and cannot be attributed to the low-level physical properties of stimuli or the earlier extraction of face gender/race information before identification. Together with complementary findings showing effects of identity analysis on gender and race categorization, these results indicate that invariant face properties are processed in an integrative way: visual analysis of one property involves, and is therefore affected by, automatic processing of the others. Implications for current theoretical models of face perception are discussed.}, web_url = {http://www.journalofvision.org/content/13/1/15.full.pdf+html}, state = {published}, DOI = {10.1167/13.1.15}, author = {Zhao M{mzhao}{Department Human Perception, Cognition and Action} and Hayward WG} } @Article{ delaRosaGBC2012, title = {The contribution of different cues of facial movement to the emotional facial expression adaptation aftereffect}, journal = {Journal of Vision}, year = {2013}, month = {1}, volume = {13}, number = {1:23}, pages = {1-15}, abstract = {Probing emotional facial expression recognition with the adaptation paradigm is one way to investigate the processes underlying emotional face recognition. Previous research suggests that these processes are tuned to dynamic facial information (facial movement). Here we examined the tuning of processes involved in the recognition of emotional facial expressions to different sources of facial movement information. Specifically we investigated the effect of the availability of rigid head movement and intrinsic facial movements (e.g., movement of facial features) on the size of the emotional facial expression adaptation effect. Using a three-dimensional (3D) morphable model that allowed the manipulation of the availability of each of the two factors (intrinsic facial movement, head movement) individually, we examined emotional facial expression adaptation with happy and disgusted faces. Our results show that intrinsic facial movement is necessary for the emergence of an emotional facial expression adaptation effect with dynamic adaptors. The presence of rigid head motion modulates the emotional facial expression adaptation effect only in the presence of intrinsic facial motion. In a second experiment we show these adaptation effects are difficult to explain by merely the perceived intensity and clarity (uniqueness) of the adaptor expressions. Together these results suggest that processes encoding facial expressions are differently tuned to different sources of facial movements.}, web_url = {http://www.journalofvision.org/content/13/1/23.full.pdf+html}, state = {published}, DOI = {10.1167/13.1.23}, author = {de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Giese MA{giese}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Article{ KrimmelKBBMDBR2013, title = {Three-Dimensional Assessment of Facial Development in Children With Unilateral Cleft Lip With and Without Alveolar Cleft}, journal = {Journal of Craniofacial Surgery}, year = {2013}, month = {1}, volume = {24}, number = {1}, pages = {313–316}, abstract = {Children with cleft lip or cleft lip and alveolus represent a minor group in the cleft population. The aim of this study was to analyze the faces of these children. In a prospective, cross-sectional study, 344 healthy children and 30 children with cleft lip or cleft lip and alveolus were scanned three-dimensionally at the age of 0 to 6 years. Twenty-one standard anthropometric landmarks were identified, and the images were superimposed. Growth curves for normal facial development were calculated. The facial morphology of cleft children was compared with that of unaffected children. Facial morphology and growth in the transverse direction of the examined patients appeared broadened in all levels. Especially the nasal landmarks indicated a widening of the nose. The landmarks ac l, sbal l, sbal r, c l, sn l, and ls l differed significantly from unaffected children. In the sagittal and vertical dimensions, there was no significant difference compared with unaffected children. Our study demonstrates that surgical and orthodontic treatment can restore the vertical and sagittal dimensions of the face in children with cleft lip with and without alveolar clefts; however, the transverse dimension—especially the nose—remains too broad.}, web_url = {http://journals.lww.com/jcraniofacialsurgery/pages/articleviewer.aspx?year=2013&issue=01000&article=00069&type=abstract}, state = {published}, DOI = {10.1097/SCS.0b013e318275ed60}, author = {Krimmel M, Kluba S, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, Bacher M, M\"uller-Hagedorn S, Dietz K, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Reinert s} } @Article{ HeydrichDAHBMB2013, title = {Visual capture and the experience of having two bodies: Direct comparison of two virtual reality techniques}, journal = {-}, year = {2013}, month = {1}, state = {published}, author = {Heydrich L, Dodds T{dodds}{Department Human Perception, Cognition and Action}, Aspell JE, Herbelin B, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Mohler B{mohler}{Department Human Perception, Cognition and Action} and Blanke O} } @Inproceedings{ ChuangNB2013, title = {A Fixed-Based Flight Simulator Study: The Interdependence of Flight Control Performance and Gaze Efficiency}, year = {2013}, month = {7}, pages = {1-10}, abstract = {Here, a descriptive study is reported that addresses the relationship between flight control performance and instrument scanning behavior. This work was performed in a fixed-based flight simulator. It targets the ability of untrained novices to pilot a lightweight rotorcraft in a flight scenario that consisted of fundamental mission task elements such as speed and altitude changes. The results indicate that better control performance occurs when gaze is more selective for and focused on key instruments. Ideal instrument scanning behavior is proposed and its relevance for training instructions and visual instrument design is discussed.}, file_url = {fileadmin/user_upload/files/publications/2013/HCI-I-2013-Chuang.pdf}, web_url = {http://www.hcii2013.org/}, event_name = {15th International Conference on Human-Computer Interaction (HCI International 2013)}, event_place = {Las Vegas, NV, USA}, state = {accepted}, author = {Chuang LL{chuang}{Department Human Perception, Cognition and Action}, Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action} and B\"ulftoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ HerdtweckC2013, title = {Monocular Car Viewpoint Estimation with Circular Regression Forests}, year = {2013}, month = {6}, pages = {1-8}, web_url = {http://www.iv2013.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE Intelligent Vehicles Symposium (IV 2013)}, event_place = {Gold Coast, Australia}, state = {accepted}, author = {Herdtweck C{grueschaan}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ SecchiFBR2013, title = {Bilateral Control of the Degree of Connectivity in Multiple Mobile-robot Teleoperation}, year = {2013}, month = {5}, pages = {-}, abstract = {This paper presents a novel bilateral controller that allows to stably teleoperate the degree of connectivity in the mutual interaction between a remote group of mobile robots considered as the slave-side. A distributed leaderfollower scheme allows the human operator to command the overall group motion. The group autonomously maintains the connectivity of the interaction graph by using a decentralized gradient descent approach applied to the Fiedler eigenvalue of a properly weighted Laplacian matrix. The degree of connectivity, and then the flexibility, of the interaction graph can be finely tuned by the human operator through an additional bilateral teleoperation channel. Passivity of the overall system is theoretically proven and extensive human/hardware in-the-loop simulations are presented to empirically validate the theoretical analysis.}, file_url = {fileadmin/user_upload/files/publications/2013/2013d-SecFraBueRob.pdf}, web_url = {http://www.icra2013.org/}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2013)}, event_place = {Karlsruhe, Germany}, state = {published}, author = {Secchi C, Franchi A{antonio}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ RyllBR2013, title = {First Flight Tests for a Quadrotor UAV with Tilting Propellers}, year = {2013}, month = {5}, pages = {1-8}, abstract = {In this work we present a novel concept of a quadrotor UAV with tilting propellers. Standard quadrotors are limited in their mobility because of their intrinsic underactuation (only 4 independent control inputs vs. their 6-dof pose in space). The quadrotor prototype discussed in this paper, on the other hand, has the ability to also control the orientation of its 4 propellers, thus making it possible to overcome the aforementioned underactuation and behave as a fully-actuated flying vehicle. We first illustrate the hardware/software specifications of our recently developed prototype, and then report the experimental results of some preliminary, but promising, flight tests which show the capabilities of this new UAV concept.}, file_url = {fileadmin/user_upload/files/publications/2013/ICRA-2013-Ryll.pdf}, web_url = {http://www.icra2013.org/}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2013)}, event_place = {Karlsruhe, Germany}, state = {published}, author = {Ryll M{maryll}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ NestmeyerRLHBRF2013, title = {Interactive Demo: Haptic Remote Control of Multiple UAVs with Autonomous Cohesive Behavior}, year = {2013}, month = {5}, pages = {1-3}, file_url = {fileadmin/user_upload/files/publications/2013/ICRA-2013-Workshop-Nestmeyer.pdf}, web_url = {http://icra2013mrs.tuebingen.mpg.de/index.php?id=56}, event_name = {ICRA 2013 Workshop Towards Fully Decentralized Multi-Robot Systems: Hardware, Software and Integration}, event_place = {Karlsruhe, Germany}, state = {published}, author = {Nestmeyer T{tnestmeyer}{Department Human Perception, Cognition and Action}, Riedel M{mriedel}{Department Human Perception, Cognition and Action}, L\"achele J{siddian}{Department Human Perception, Cognition and Action}, Hartmann S{shartmann}{Department Human Perception, Cognition and Action}, Botschen F{fbotschen}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ NestmeyerRF2013, title = {Multi-target Simultaneous Exploration with Continual Connectivity}, year = {2013}, month = {5}, pages = {-}, web_url = {https://sites.google.com/site/icra2013manyrobotsworkshop/}, event_name = {ICRA 2013 International Workshop on Crossing the Reality Gap: From Single to Multi- to Many Robot Systems}, event_place = {Karlsruhe, Germany}, state = {published}, author = {Nestmeyer T{tnestmeyer}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ LacheleRRF2013, title = {SwarmSimX and TeleKyb: Two ROS-integrated Software Frameworks for Single- and Multi-Robot Applications}, year = {2013}, month = {5}, pages = {1-3}, abstract = {In this notes we briefly review two software frameworks that have been developed within the Autonomous Robotics and Human-machine Systems group (formerly, Human-Robot Interaction group) at the Max Plank Institute for Biological Cybernetics. Both frameworks, starting from the early versions up to the most recent releases, have been successfully employed in several works of the group, including, e.g., [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]. For a detailed description of SwarmSimX, we refer the interested reader to [13], [14]. The TeleKyb framework is instead described thoroughly in [15] and available at http://www.ros.org/wiki/telekyb. .}, file_url = {fileadmin/user_upload/files/publications/2013/ICRA-2013-Workshop-Laechele.pdf}, web_url = {http://icra2013mrs.tuebingen.mpg.de/index.php?id=56}, event_name = {ICRA 2013 Workshop Towards Fully Decentralized Multi-Robot Systems: Hardware, Software and Integration}, event_place = {Karlsruhe, Germany}, state = {published}, author = {L\"achele J{siddian}{Department Human Perception, Cognition and Action}, Riedel M{mriedel}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ RiedelFRBS2012, title = {Experiments on Intercontinental Haptic Control of Multiple UAVs}, year = {2013}, pages = {227-238}, abstract = {In this paper we propose and experimentally validate a bilateral teleoperation framework where a group of UAVs are controlled over an unreliable network with typical intercontinental time delays and packet losses. This setting is meant to represent a realistic and challenging situation for the stability the bilateral closed-loop system. In order to increase human telepresence, the system provides the operator with both a video stream coming from the onboard cameras mounted on the UAVs, and with a suitable haptic cue, generated by a forcefeedback device, informative of the UAV tracking performance and presence of impediments on the remote site. In addition to the theoretical background, we describe the hardware and software implementation of this intercontinental teleoperation: this is composed of a semi-autonomous group of multiple quadrotor UAVs, a 3-DOF haptic interface, and a network connection based on a VPN tunnel between Germany and South Korea. The whole software framework is based upon the Robotic Operating System (ROS) communication standard.}, file_url = {fileadmin/user_upload/files/publications/2012/IAS-2012-Riedel2.pdf}, web_url = {http://www.ias-12.org/main/}, editor = {Lee, S. , H. Cho, K.-J. Yoon, J. Lee}, publisher = {Springer}, address = {Berlin, Germany}, booktitle = {Intelligent Autonomous Systems 12}, event_name = {12th International Conference on Intelligent Autonomous Systems (IAS-12)}, event_place = {Jeju Island, South Korea}, state = {published}, ISBN = {978-3-642-33931-8}, DOI = {10.1007/978-3-642-33932-5_22}, author = {Riedel M{mriedel}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Son HI{chakurt}{Department Human Perception, Cognition and Action}} } @Inbook{ ProffittL2011, title = {Perception viewed as a phenotypic expression}, year = {2013}, month = {2}, pages = {171-198}, file_url = {fileadmin/user_upload/files/publications/2012/Proffitt-LinkenaugerZiFChapterColorPicsEmbedded.pdf}, web_url = {https://mitpress.mit.edu/books/action-science}, editor = {Prinz, W. , M. Beisert, A. Herwig}, publisher = {MIT Press}, address = {Cambridge, MA, USA}, booktitle = {Action science: foundations of an emerging discipline}, state = {published}, ISBN = {978-0-262-01855-5}, author = {Proffitt DR and Linkenauger SA{sally}{Department Human Perception, Cognition and Action}} } @Poster{ DobsBBVCS2013, title = {Quantifying Human Sensitivity to Spatio-Temporal Information in Dynamic Faces}, year = {2013}, month = {8}, web_url = {http://www.ecvp.uni-bremen.de/}, event_name = {36th European Conference on Visual Perception (ECVP 2013)}, event_place = {Bremen. Germany}, state = {accepted}, author = {Dobs K{kdobs}{Department Human Perception, Cognition and Action}, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, Vuong Q{qvuong}{Department Human Perception, Cognition and Action}, Curio C{curio}{Department Human Perception, Cognition and Action} and Schultz J{johannes}{Department Human Perception, Cognition and Action}} } @Poster{ PariseKE2013, title = {On pitch-elevation mapping: Nature, nurture and behaviour}, year = {2013}, month = {6}, day = {4}, volume = {14}, number = {157}, abstract = {The association between auditory pitch and spatial elevation is one the most fascinating examples of cross-dimensional mappings: in a wide range of cognitive, perceptual, attentional and linguistic tasks, humans consistently display a positive, sometimes absolute, association between auditory pitch and spatial elevation. However, the origins of such a pervasive mapping are still largely unknown. Through a combined analysis of environmental sounds and anthropometric measures, we demonstrate that, statistically speaking, this mapping is already present in both the distal and the proximal stimulus. Specifically, in the environment, high sounds are more likely to come from above; moreover, due to the filtering properties of the external ear, sounds coming from higher elevations have more energy at high frequencies. Next, we investigated whether the internalized mapping depends on the statistics of the proximal, or of the distal stimulus. In a psychophysical task, participants had to localize narrow band-pass noises with different central frequencies, while head- and world-centred reference frames were put into conflict by tilting participants’ body orientation. The frequency of the sounds systematically biased localization in both head- and world-centred coordinates, and, remarkably, in agreement with the mappings measured in both the distal and proximal stimulus. These results clearly demonstrate that the cognitive mapping between pitch and elevation mirror the statistical properties of the auditory signals. We argue that, in a shorter time-scale, humans learn the statistical properties auditory signals; while, in a longer timescale, the evolution of the acoustic properties of the external ear itself is shaped by the statistics of the acoustic environment.}, web_url = {http://shoreserv.mcmaster.ca/IMRF/ocs5/index.php/imrf/2013/paper/view/157}, event_name = {14th International Multisensory Research Forum (IMRF 2013)}, event_place = {Jerusalem, Israel}, state = {published}, author = {Parise CV{cesare}{Research Group Multisensory Perception and Action}, Knorre K and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Poster{ SennaMBP2013, title = {The marble-hand illusion}, year = {2013}, month = {6}, day = {4}, volume = {14}, number = {162}, abstract = {Our body is made of flesh and bones. We know it, and in our daily lives all the senses – including touch, vision, and audition – constantly provide converging information about this simple, factual truth. But is this necessarily always the case? Here we report a surprising bodily illusion demonstrating that human observers rapidly update their assumptions about the material qualities of their body, based on their recent multisensory perceptual experience. To induce an illusory misperception of the material properties of the hand, we repeatedly gently hit participants’ hand, while progressively replacing the natural sound of the hammer against the skin with the sound of a hammer hitting a piece of marble. After five minutes, the hand started feeling stiffer, heavier, harder, less sensitive, and unnatural, and showed enhanced Galvanic skin response to threatening stimuli. This novel bodily illusion, the ’Marble-Hand Illusion’, demonstrates that the experience of the material of our body, surely the most stable attribute of our bodily self, can be quickly updated through multisensory integration.}, web_url = {http://shoreserv.mcmaster.ca/IMRF/ocs5/index.php/imrf/2013/paper/view/162}, event_name = {14th International Multisensory Research Forum (IMRF 2013)}, event_place = {Jerusalem, Israel}, state = {published}, author = {Senna I, Maravita A, Bolognini N and Parise CV{cesare}{Research Group Multisensory Perception and Action}} } @Poster{ JungBTLA2013, title = {The Role of Race in Summary Representations of Faces}, year = {2013}, month = {5}, day = {13}, volume = {13}, pages = {208}, abstract = {One possibility to overcome the processing limitation of the visual system is to attend selectively to relevant information only. Another strategy is to process sets of objects as ensembles and represent their average characteristics instead of individual group members (e.g., mean size, brightness, orientation). Recent evidence suggests that ensemble representation might occur even for human faces (for a summary, see Alvarez, 2011), i.e., observers can extract the mean emotion, sex, and identity from a set of faces (Habermann & Whitney, 2007; de Fockert & Wolfenstein, 2009). Here, we extend this line of research into the realm of face race: Can we extract the "mean race" of a set of faces when no conscious perception of single individuals is possible? Moreover, does the visual system process own- and other-race faces differently at this stage? Face stimuli had the same (average) male identity but were morphed, at different levels, in between Asian and Caucasian appearance. Following earlier studies (e.g., Habermann & Whitney, 2007, 2010), observers were briefly (250ms) presented with random sets of 12 of these faces. They were then asked to adjust a test face to the perceived mean race of the set by "morphing" it between Asian and Caucasian appearance. The results show that for most participants the response error distribution is significantly different from random, while their responses are centered around the real stimulus set mean - suggesting that they are able to extract "mean race". Also, we find a bias towards responding more "Asian" than the actual mean of a face set. All participants tested so far are South Korean (from Seoul), indicating that even at this early (unconscious) processing stage, the visual system distinguishes between own- and other-race faces, giving more weight to the former. Follow-up experiments on Caucasian participants will be performed to validate this observation.}, web_url = {http://www.visionsciences.org/abstract_detail.php?id=1500}, event_name = {13th Annual Meeting of the Vision Sciences Society (VSS 2013)}, event_place = {Naples, FL, USA}, state = {published}, author = {Jung W-M{wjung}{Department Human Perception, Cognition and Action}, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}, Thornton I{ian}{Department Human Perception, Cognition and Action}, Lee S-W and Armann R{armann}{Department Human Perception, Cognition and Action}} } @Poster{ VolkovaMB2013, title = {Display size of biological motion stimulus influences performance in a complex emotional categorization task}, year = {2013}, month = {5}, day = {11}, volume = {13}, pages = {56}, abstract = {People are remarkably good at detecting familiarity with actor (Loula et al., 2005), recognizing the gender (Pollick et al., 2005), emotions (Atkinson et al., 2004) and actions of an actor when presented as biological motion. For many of these tasks the influence of the type of stimuli display (point light display, virtual avatar, full light video) on participants' performance has been well researched (McDonnell et al., 2009). The effect of the size of the display, however, remains underinvestigated. According to our hypothesis, a naturalistic environment and stimuli display would enhance performance, in particular for challenging tasks. We motion captured eight actors, who were asked to portray the following ten emotions while seated: amusement, anger, disgust, fear, joy, pride, relief, sadness, shame, and surprise. The resulting 80 motion sequences were then applied to a stick figure and used for the emotion recognition study. As a between participant factor, the stick figure animations were presented either on a laptop screen or on a large back projection surface. In the latter condition the size of the stick figure matched the natural size of the actors. Thirty-two participants (16 female) took part in a between-subject study (gender balanced). For each stimulus the participant had to make a ten-alternative forced choice to categorize the animation as one of ten emotions. Recognition accuracy was significantly higher for natural size condition (38% accuracy for back projection condition vs. 31% for desktop), and reaction time was lower (2.3 animation repetitions for back projection condition vs. 2.7 for desktop condition). In both conditions the emotional categories were an important factor as some emotions were more easily recognized than others. The results show that for complex tasks, e.g. discrimination among multiple emotional categories, enhanced naturalness of stimuli can be beneficiary for the observer.}, web_url = {http://www.visionsciences.org/abstract_detail.php?id=303}, event_name = {13th Annual Meeting of the Vision Sciences Society (VSS 2013)}, event_place = {Naples, FL, USA}, state = {published}, author = {Volkova EP{evolk}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ CurioCG2013, title = {Integration of kinematic components in the perception of emotional facial expressions}, year = {2013}, month = {8}, web_url = {http://www.ecvp.uni-bremen.de/}, event_name = {36th European Conference on Visual Perception (ECVP 2013)}, event_place = {Bremen, Germany}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}, Chiovetto E and Giese MA{giese}} } @Conference{ pariseE2013, title = {Multisensory mechanisms for perceptual disambiguation: A classification image study on the stream-bounce illusion}, year = {2013}, month = {6}, day = {6}, volume = {14}, number = {159}, abstract = {Sensory information is inherently ambiguous, and a given signal can in principle correspond to infinite states of the world. A primary task for the observer is therefore to disambiguate sensory information and accurately infer the actual state of the world. Here, we take the stream-bounce illusion as a tool to investigate perceptual disambiguation from a cue-integration perspective, and explore how humans gather and combine sensory information to resolve ambiguity. In a classification task, we presented two bars moving in opposite directions along the same trajectory meeting at the centre. We asked observers to classify such ambiguous displays as streaming or bouncing. Stimuli were embedded in dynamic audiovisual noise, so that through a reverse correlation analysis, we could estimate the perceptual templates used for the classification. Such templates, the classification images, describe the spatiotemporal statistical properties of the noise, which are selectively associated to either percept. Our results demonstrate that the features of both visual and auditory noise, and interactions thereof, strongly biased the final percept towards streaming or bouncing. Computationally, participants’ performance is explained by a model involving a matching stage, where the perceptual systems cross-correlate the sensory signals with the internal templates; and an integration stage, where matching estimates are linearly combined to determine the final percept. These results demonstrate that observers use analogous MLE-like integration principles for categorical stimulus properties (stream/bounce decisions) as they do for continuous estimates (object size, position, etc…). Finally, the time-course of the classification images reveal that most of the decisional weight for disambiguation is assigned to information gathered before the physical crossing of the stimuli, thus highlighting a predictive nature of perceptual disambiguation.}, web_url = {http://shoreserv.mcmaster.ca/IMRF/ocs5/index.php/imrf/2013/paper/view/159}, event_name = {14th International Multisensory Research Forum (IMRF 2013)}, event_place = {Jerusalem, Israel}, state = {published}, author = {Parise CV{cesare}{Research Group Multisensory Perception and Action} and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Conference{ HartcherO039BrienSA2013, title = {At the tip of the fingers: the role of orientation and position on the reference frames used to interpret ambiguous stimuli presented to the hand}, year = {2013}, month = {6}, day = {5}, volume = {14}, number = {231}, abstract = {Coding an object or events position in the environment involves recruitment of multiple reference frames or coordinate systems. Generally retino-, head-, trunk-, arm and object-centred representations have been shown to influence how we estimate relative object position. Visual information can primarily be coded in retinotopic or spatiotopic frames while tactile information does not provide such a one-to-one mapping between position in space and receptor activation. The question asked here is how tactile information presented to the hand, which is able to change its orientation in space and body coordinates, influences interpretation of tactile letter stimuli. As letters are generally perceived visually, when interpreting a letter traced on the skin, one might assume that the perceptual system defaultly employs a visual frame of reference, or at least a simple egocentric perspective. However, previous findings suggest that for cutaneous tracing the perspective taken is influenced in a complex manner by factors such as location, as opposed to receptor type, limb orientation, location of stimulation relative to other body parts and object coordinates (Parsons & Shimojo, 1987). In three experiments we explored the initial interpretation of letter stimuli d, b, p, & q when presented to the hand and fingertips. The stimuli are ambiguous along left/right and top/bottom axes and are therefore ideal for inferring reference frame adopted. The current findings suggest that orientation and position of the hand relative to the body, alters the reference frame selected when interpreting tactile letter stimuli. The results are consistent with a multiple reference frame model of information processing and allow us to disentangle the elements involved in perception of cutaneous stimulation at our fingertips.}, web_url = {http://shoreserv.mcmaster.ca/IMRF/ocs5/index.php/imrf/2013/paper/view/231}, event_name = {14th International Multisensory Research Forum (IMRF 2013)}, event_place = {Jerusalem, Israel}, state = {published}, author = {Hartcher-O'Brien J{jhartcher}, Spence CJ and Auvray M} } @Conference{ ArnoldHSA2013, title = {The cost of adopting and adapting tactile frames of reference}, year = {2013}, month = {6}, day = {5}, volume = {14}, number = {179}, abstract = {Visual information is predominantly interpreted within an eye-centered reference frame. Tactile information, on the other hand, can be interpreted within different reference frames, i.e., local-surface, or whole-body centered. An important question is whether, given the different possibilities, each observer has a natural reference frame that they consistently adopt in different conditions, or they can freely adopt several reference frames and switch from one to another without cost. Recognition of ambiguous asymmetrical tactile letters (e.g., b, d, p, q) allows us to interrogate the different reference frames adopted by observers when interpreting tactile information. For such stimuli drawn on the skin, recognition requires assigning top-bottom, left-right and front-back axes to the letter. Across several experiments, participants had to recognize these letters when presented on different body surfaces, either with a freely adopted reference frame or an imposed one. In the unconstrained condition, participants consistently adopted one reference frame, with between-participant differences being evident. When adapted to a new reference frame, interpretation of the letters produced an important cost in response accuracies and latencies, indicating that the freely adopted reference frame corresponded to a natural reference frame rather than an arbitrary choice. This cost was greater for the freely-adopted egocentric (head- or body-centered) than for the non-egocentric (off-centered) reference frame. By training participants with a particular set of symbols, we then tested for generalization to novel stimuli and body surfaces. Our results have implications for the design of visuo-tactile sensory substitution devices and for understanding emergence of the distal attribution phenomenon.}, web_url = {http://shoreserv.mcmaster.ca/IMRF/ocs5/index.php/imrf/2013/paper/view/179}, event_name = {14th International Multisensory Research Forum (IMRF 2013)}, event_place = {Jerusalem, Israel}, state = {published}, author = {Arnold G, Hartcher-O'Brien J{jhartcher}, Spence C and Auvray M} } @Conference{ Curio2013_2, title = {Design and Optimization of Computer-Vision based Car-User Interfaces}, year = {2013}, month = {6}, day = {4}, event_name = {Leopold Kostal GmbH}, event_place = {Lüdenscheid, Germany}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}} } @Conference{ delaRosaSGBC2013, title = {Visual adaptation aftereffects to actions are modulated by high-level action interpretations}, year = {2013}, month = {5}, day = {11}, volume = {13}, pages = {40}, abstract = {Action recognition is critical for successful human interaction. Previous research highlighted the importance of the motor system to visual action recognition. Little is known about the visual tuning properties of processes involved in action recognition. Here we examined the visual tuning properties of processes involved in action recognition by means of a behavioral adaptation paradigm. Participants looked at an adaptor image (showing a person hitting or waving) for 4s and subsequently categorized a briefly presented test image as either hitting or waving. The test images were sampled from a video sequence showing a person moving from a hitting to a waving pose. We found the perception of the ambiguous test image to be significantly biased away from the adapted action (action adaptation aftereffect (AAA)). In subsequent experiments we investigated the origin of the AAA. The contrast inversion and mirror flipping of the adaptor image relative to the test images did not abolish the AAA suggesting that local contrastive sensitive units are not solely responsible for the AAA. Similarly the AAA was present when we chose adaptor images that were equated in terms of their emotional content indicating that the AAA is not merely mediated by units sensitive to the emotional content of an action. Moreover presenting words (e.g. "hitting" or "waving") instead of images as adaptors led to the disappearance of the AAA providing evidence that abstract high level linguistic cues about actions alone did not induce the AAA. Finally we changed the action interpretation of the adaptors leaving their physical properties unchanged by means of priming. We found that the priming of the action interpretation of the adaptors modulated the size of the AAA. Im summary these results suggest that mechanisms underlying action recognition are particularly sensitive to the high-level interpretation of an action.}, web_url = {http://www.visionsciences.org/abstract_detail.php?id=696}, event_name = {13th Annual Meeting of the Vision Sciences Society (VSS 2013)}, event_place = {Naples, FL, USA}, state = {published}, author = {de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Streuber S{stst}{Department Human Perception, Cognition and Action}, Giese M{giese}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Conference{ FranchiR2013, title = {Autonomy and Human Interaction in Multi-Robot Systems}, year = {2013}, month = {5}, web_url = {http://icra2013mrs.tuebingen.mpg.de/index.php?id=56}, event_name = {ICRA 2013 Workshop Towards Fully Decentralized Multi-Robot Systems: Hardware, Software and Integration}, event_place = {Karlsruhe, Germany}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2013_3, title = {Autonomous Control and Human Interaction in Multiple Robots Systems}, year = {2013}, month = {4}, day = {17}, abstract = {This topic of this talk will centered around the recent work of the Autonomous Robotics and Human-Machine Systems group at the Max Planck Institute for Biological Cybernetics in the field of multi-robot system control. The talk will present fully-autonomous algorithms and human-in-the-loop methods as well. In the field of autonomous algorithms, the talk will include the following topics: vision-based formation control, mutual localization without identity information, decentralized maintenance of an extended version of the connectivity/rigidity concepts in multi-robot networks. Concerning the human-in-the-loop field, the talk will present a framework that allows multiple operators to perform shared control of multiple robots in a bilateral way, i.e., with the presence of haptic feedback. Both the theoretical methodologies behind the developed algorithms and the practical application on a real group of multiple UAVs (quadrotors) will be shown during the talk.}, web_url = {http://www.gkmm.tu-darmstadt.de/?q=node/1301}, event_name = {Department of Computer Science, Technische Universität Darmstadt}, event_place = {Darmstadt, Germany}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2013, title = {Decentralized Control of Multiple-robot Systems}, year = {2013}, month = {3}, day = {20}, web_url = {http://www.eurobotics2013.com/}, event_name = {2013 euRobotics Forum: Multi-Robot Exploration Workshop}, event_place = {Lyon, France}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2013_2, title = {Shared Control of Multiple Mobile Robots}, year = {2013}, month = {3}, day = {6}, abstract = {This talk will show some recent theoretical and experimental results in the multi-robot field, with special attention to the UAV (Unmanned Aerial Vehicle) case. The main topic will the presentation of a novel control framework where a team of human assistants are able to interact with a group of semi-autonomous mobile robots by using haptic interfaces. Within this framework, special attention will be given to the following topics: formation control by means of camera sensors, generalized connectivity and rigidity maintenance of the robotic network, mutual localization without identity measurements, human/multi-robot collaboration. The talk will present both the theoretical methodologies used in the control algorithms and the practical aspects behind the application on a group multiple quadrotor UAVs.}, web_url = {https://www.cs.bham.ac.uk/events/seminars/seminar_details.html?seminar_id=1021}, event_name = {Schools of Mechanical Engineering and Computer Science, University of Birmingham}, event_place = {Birmingham, UK}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ Curio2013, title = {Novel Design Principles for Interfacing Artificial and Human Vision for Assistive Perceiving Systems}, year = {2013}, month = {3}, day = {4}, abstract = {Studying the interface between artificial and biological vision has been an area of research that has been greatly promoted for a long time. It seems promising that cognitive science can provide new ideas to interface computer vision and human perception, yet no established design principles do exist. In the first part of my talk I am going to introduce the novel concept of 'object detectability'. Object detectability refers to a measure of how likely a human observer is visually aware of the location and presence of specific object types in a complex, dynamic, urban scene. We have shown a proof of concept of how to maximize human observers' scene awareness in a dynamic driving context. Nonlinear functions are learnt from experimental samples of a combined feature vector of human gaze and visual features mapping to object detectabilities. We obtain object detectabilities through a detection experiment, simulating a proxy task of distracted real-world driving. In order to specifically enhance overall pedestrian detectability in a dynamic scene, the sum of individual detectability predictors defines a complex cost function that we seek to optimize with respect to human gaze. Results show significantly increased human scene awareness in hazardous test situations comparing optimized gaze and random fixation. Thus, our approach can potentially help a driver to save reaction time and resolve a risky maneuvre. In our framework, the remarkable ability of the human visual system to detect specific objects in the periphery has been implicitly characterized by our perceptual detectability task and has thus been taken into account. The framework may provide a foundation for future work to determine what kind of information a Computer Vision system should process reliably, e.g. certain pose or motion features, in order to optimally alert a driver in time-critical situations. Dynamic image data was taken from the Caltech Pedestrian database. I will conclude with a brief overview of recent work, including a new circular output random regression forest for continuous object viewpoint estimation and a novel learning-based, monocular odometry approach based on robust LVMs and sensorimotor learning, offering stable 3D information integration. Last but not least, I present results of a perception experiment to quantify emotion in estimated facial movement synergy components that can be exploited to control emotional content of 3D avatars in a perceptually meaningful way.}, event_name = {Max Planck Institute for Intelligent Systems: Perceiving Systems Department}, event_place = {Tübingen, Germany}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}} } @Book{ Nieuwenhuizen2012_3, title = {Changes in Pilot Control Behaviour across Stewart Platform Motion Systems}, year = {2012}, month = {9}, pages = {266}, abstract = {Flight simulators provide an effective, efficient, and safe environment for practising flight-critical manoeuvres without requiring a real aircraft. In general, high-performance full flight simulators are used for training tasks that require simulator motion, although low-cost motion systems have been proposed for certain training tasks that only require limited motion cues. These systems have shorter stroke actuators, lower bandwidth, and higher motion noise. The influence of these characteristics on pilot perception and control behaviour is unknown. In this thesis, this is investigated by simulating a model of a simulator with limited capabilities on a high-end simulator. The simulator limitations, which consist of a platform filter, time delay, and noise characteristics, can then be removed one by one and their effect on control behaviour studied in isolation. Pilot perception and control behaviour was identified in an experimental closed-loop control task. The time delay and noise characteristics of the simulators did not have an effect on pilot behaviour. However, it was found that the bandwidth of the motion system had a significant effect on performance and control behaviour. Results indicate that the motion cues were barely used at all in conditions with a low bandwidth, and that participants relied on the visual cues to perform the control task. The approach used in this thesis provided valuable insight into changes in pilot response dynamics that form the basis of observed changes in performance. The results demonstrated that simulator motion cues must be considered carefully in piloted control tasks in simulators and that measured results depend on simulator characteristics as pilots adapt their control behaviour to the available cues.}, web_url = {http://www.logos-verlag.de/cgi-bin/engbuchmid?isbn=3233&lng=deu&id=}, publisher = {Logos Verlag}, address = {Berlin, Germany}, series = {MPI Series in Biological Cybernetics ; 33}, state = {published}, ISBN = {978-3-8325-3233-8}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}} } @Book{ Breidt2012, title = {Datenbasierte Gesichtsanimation}, year = {2012}, month = {4}, pages = {175}, abstract = {Die Erzeugung realistischer 3D-Computeranimationen von Gesichtern ist auf Grund der hohen Bedeutung des menschlichen Gesichts für eine Vielzahl von Anwendungsbereichen von Interesse. Neben virtuellen Schauspielern in der Film- und Computerspiele-Industrie oder Online-Avataren verlangt auch die experimentelle Untersuchung der menschlichen Wahrnehmung von Gesichtern nach effizienten Lösungen zur Erstellung von Gesichtsanimationen. Insbesondere die experimentelle Verwendung motiviert den in dieser Arbeit vertretenen datenbasierten Ansatz, der möglichst ohne die in der Industrie übliche kreativ-handwerkliche Gestaltung der Gesichtsdaten auskommen will. Die Arbeit beschreibt, wie Messdaten realer Gesichter in Form von Motion Capture sowie 3D- bzw. 4D-Scans für diese Aufgabe eingesetzt werden können. Ausgehend von der Grundannahme der Darstellbarkeit eines Gesichts und dessen Bewegungen als Linearkombination werden Möglichkeiten der Gewinnung und Nutzung solcher Daten aufgezeigt: Der erste Teil kombiniert statische Oberflächenmessungen des Gesichts in Form von räumlich hoch aufgelösten 3D-Scans mit den zeitlich hoch aufgelösten, markerbasierten Bewegungsdaten eines Motion-Capture-Systems. Hierzu werden die gemessenen Bewegungen durch eine semantische Parametrisierung auf Basis des Facial Action Coding Systems (FACS) dargestellt. Dies erlaubt nicht nur die identitätsunabhängige Übertragung der Bewegung auf ein beliebiges Gesicht, sondern auch eine kompakte und gleichzeitig interpretierbare Beschreibung der Bewegung. Die zweite Hälfte der Arbeit baut auf neuen Messverfahren auf, die eine detaillierte 3D-Aufnahme des zeitlichen und räumlichen Verlaufs komplexer Gesichtsbewegungen in einem einzigen Aufnahmevorgang als 4D-Scan ermöglichen. Um solche Daten jedoch systematisch einsetzen und verändern zu können, werden Methoden zur Herstellung einer Korrespondenz zwischen den einzelnen Zeitschritten der Aufnahme benötigt. Hierzu werden sowohl ein modellfreies Verfahren als auch ein modellbasiertes Verfahren zur Rekonstruktion von Gesichtsbewegungen vorgestellt. Mit Hilfe des modellbasierten Ansatzes wird zudem gezeigt, wie stark verrauschte Daten echtzeitfähiger Tiefensensoren rekonstruiert werden können. Schließlich wird die modellbasierten Bewegungsanalyse dazu verwendet, aus Aufnahmen komplexer Gesichtsbewegungen FACS-Aktivierungen zu gewinnen und damit ein individuelles Gesichtsmodell zu berechnen, das interpretierbare Parameter besitzt.}, web_url = {http://www.logos-verlag.de/cgi-bin/buch/isbn/3136}, publisher = {Logos Verlag}, address = {Berlin, Germany}, series = {MPI Series in Biological Cybernetics ; 32}, state = {published}, ISBN = {978-3-8325-3136-2}, author = {Breidt M{mbreidt}{Department Human Perception, Cognition and Action}} } @Article{ LinkenaugerLRP2012, title = {A Perceptual–Motor Deficit Predicts Social and Communicative Impairments in Individuals With Autism Spectrum Disorders}, journal = {Autism Research}, year = {2012}, month = {10}, volume = {5}, number = {5}, pages = {352–362}, abstract = {Individuals with autism spectrum disorders (ASDs) have known impairments in social and motor skills. Identifying putative underlying mechanisms of these impairments could lead to improved understanding of the etiology of core social/communicative deficits in ASDs, and identification of novel intervention targets. The ability to perceptually integrate one's physical capacities with one's environment (affordance perception) may be such a mechanism. This ability has been theorized to be impaired in ASDs, but this question has never been directly tested. Crucially, affordance perception has shown to be amenable to learning; thus, if it is implicated in deficits in ASDs, it may be a valuable unexplored intervention target. The present study compared affordance perception in adolescents and adults with ASDs to typically developing (TD) controls. Two groups of individuals (adolescents and adults) with ASDs and age-matched TD controls completed well-established action capability estimation tasks (reachability, graspability, and aperture passability). Their caregivers completed a measure of their lifetime social/communicative deficits. Compared with controls, individuals with ASDs showed unprecedented gross impairments in relating information about their bodies' action capabilities to visual information specifying the environment. The magnitude of these deficits strongly predicted the magnitude of social/communicative impairments in individuals with ASDs. Thus, social/communicative impairments in ASDs may derive, at least in part, from deficits in basic perceptual–motor processes (e.g. action capability estimation). Such deficits may impair the ability to maintain and calibrate the relationship between oneself and one's social and physical environments, and present fruitful, novel, and unexplored target for intervention.}, web_url = {http://onlinelibrary.wiley.com/doi/10.1002/aur.1248/pdf}, state = {published}, DOI = {10.1002/aur.1248}, author = {Linkenauger S{sally}{Department Human Perception, Cognition and Action}, Lerner MD, Ramenzoni VC and Proffitt D} } @Article{ GeneweinB2012, title = {A sensorimotor paradigm for Bayesian model selection}, journal = {Frontiers in Human Neuroscience}, year = {2012}, month = {10}, volume = {6}, number = {291}, pages = {1-16}, abstract = {Sensorimotor control is thought to rely on predictive internal models in order to cope efficiently with uncertain environments. Recently, it has been shown that humans not only learn different internal models for different tasks, but that they also extract common structure between tasks. This raises the question of how the motor system selects between different structures or models, when each model can be associated with a range of different task-specific parameters. Here we design a sensorimotor task that requires subjects to compensate visuomotor shifts in a three-dimensional virtual reality setup, where one of the dimensions can be mapped to a model variable and the other dimension to the parameter variable. By introducing probe trials that are neutral in the parameter dimension, we can directly test for model selection. We found that model selection procedures based on Bayesian statistics provided a better explanation for subjects’ choice behavior than simple non-probabilistic heuristics. Our experimental design lends itself to the general study of model selection in a sensorimotor context as it allows to separately query model and parameter variables from subjects.}, web_url = {http://www.frontiersin.org/Human_Neuroscience/10.3389/fnhum.2012.00291/abstract}, state = {published}, DOI = {10.3389/fnhum.2012.00291}, author = {Genewein T{tgenewein}{Research Group Sensorimotor Learning and Decision-Making} and Braun DA{dbraun}{Research Group Sensorimotor Learning and Decision-Making}} } @Article{ YuilleB2012, title = {Action as an innate bias for visual learning}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, year = {2012}, month = {10}, volume = {109}, number = {44}, pages = {17736-17737}, abstract = {Babies are faced at birth with a buzzing blooming confusion of visual stimuli (1). The set of all possible images is truly enormous (2), and simple calculations suggest that only a small fraction of all possible images have ever been seen over the entire history and prehistory of mankind. Moreover, the world consists of an estimated number of 30,000 objects (3), which occur in more than 1,000 different types of scenes. How can an infant start making sense of the visual world? Detailed models of how infants learn to understand images and the balance between nature and nurture are currently lacking. Studies suggest that visual abilities develop in a stereotyped order (4). In particular, infants appear to be able to perceive motion and detect faces at an early stage of development. They can probably exploit the regularities that motion tends to be smooth in space and time, which also enables them to track image patches. Vision researchers have also demonstrated that many vertebrates and insects rely heavily on motion perception for surviving in this complex visual world, e.g., for camouflage breaking or figure ground separation (5, 6), and there are computational models that relate to neural circuitry (7).}, web_url = {http://www.pnas.org/content/109/44/17736.full.pdf+html}, state = {published}, DOI = {10.1073/pnas.1215851109}, author = {Yuille AL{yuille} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ FranchiSSBR2012, title = {Bilateral Teleoperation of Groups of Mobile Robots with Time-Varying Topology}, journal = {IEEE Transaction on Robotics}, year = {2012}, month = {10}, volume = {28}, number = {5}, pages = {1019-1033}, abstract = {In this paper, a novel decentralized control strategy for bilaterally teleoperating heterogeneous groups of mobile robots from different domains (aerial, ground, marine, and underwater) is proposed. By using a decentralized control architecture, the group of robots, which is treated as the slave side, is made able to navigate in a cluttered environment while avoiding obstacles, interrobot collisions, and following the human motion commands. Simultaneously, the human operator acting on the master side is provided with a suitable force feedback informative of the group response and of the interaction with the surrounding environment. Using passivity-based techniques, we allow the behavior of the group to be as flexible as possible with arbitrary split and join events (e.g., due to interrobot visibility/packet losses or specific task requirements) while guaranteeing the stability of the system. We provide a rigorous analysis of the system stability and steady-state characteristics and validate performance through human/hardware-in-the-loop simulations by considering a heterogeneous fleet of unmanned aerial vehicles (UAVs) and unmanned ground vehicles as a case study. Finally, we also provide an experimental validation with four quadrotor UAVs.}, file_url = {fileadmin/user_upload/files/publications/2012/2012e-FraSecSonBueRob.pdf}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6199993}, state = {published}, DOI = {10.1109/TRO.2012.2196304}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}, Secchi C, Son HI{chakurt}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Article{ PrettoBRB2012, title = {Foggy perception slows us down}, journal = {eLife}, year = {2012}, month = {10}, volume = {1}, pages = {1-12}, abstract = {Visual speed is believed to be underestimated at low contrast, which has been proposed as an explanation of excessive driving speed in fog. Combining psychophysics measurements and driving simulation, we confirm that speed is underestimated when contrast is reduced uniformly for all objects of the visual scene independently of their distance from the viewer. However, we show that when contrast is reduced more for distant objects, as is the case in real fog, visual speed is actually overestimated, prompting drivers to decelerate. Using an artificial anti-fog—that is, fog characterized by better visibility for distant than for close objects, we demonstrate for the first time that perceived speed depends on the spatial distribution of contrast over the visual scene rather than the global level of contrast per se. Our results cast new light on how reduced visibility conditions affect perceived speed, providing important insight into the human visual system.}, web_url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3479833/}, state = {published}, DOI = {10.7554/eLife.00031}, EPUB = {e00281}, author = {Pretto P{pretto}{Department Human Perception, Cognition and Action}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}, Rainer G{gregor} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ FranchiMGRBR2012, title = {Modeling and Control of UAV Bearing-Formations with Bilateral High-Level Steering}, journal = {International Journal of Robotics Research}, year = {2012}, month = {10}, volume = {31}, number = {12}, pages = {1504-1525}, abstract = {In this paper we address the problem of controlling the motion of a group of unmanned aerial vehicles (UAVs) bound to keep a formation defined in terms of only relative angles (i.e. a bearing formation). This problem can naturally arise within the context of several multi-robot applications such as, e.g. exploration, coverage, and surveillance. First, we introduce and thoroughly analyze the concept and properties of bearing formations, and provide a class of minimally linear sets of bearings sufficient to uniquely define such formations. We then propose a bearing-only formation controller requiring only bearing measurements, converging almost globally, and maintaining bounded inter-agent distances despite the lack of direct metric information. The controller still leaves the possibility of imposing group motions tangent to the current bearing formation. These can be either autonomously chosen by the robots because of any additional task (e.g. exploration), or exploited by an assisting human co-operator. For this latter ‘human-in-the-loop’ case, we propose a multi-master/multi-slave bilateral shared control system providing the co-operator with some suitable force cues informative of the UAV performance. The proposed theoretical framework is extensively validated by means of simulations and experiments with quadrotor UAVs equipped with onboard cameras. Practical limitations, e.g. limited field-of-view, are also considered.}, file_url = {fileadmin/user_upload/files/publications/2012/2012q-FraMasGraRylBueRob-preprint.pdf}, web_url = {http://ijr.sagepub.com/content/early/2012/10/05/0278364912462493.full.pdf+html}, state = {published}, DOI = {10.1177/0278364912462493}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}, Masone C{masone}{Department Human Perception, Cognition and Action}, Grabe V{vgrabe}{Department Human Perception, Cognition and Action}, Ryll M{maryll}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Article{ 6459, title = {Design of a Haptic Interface for a Gastrointestinal Endoscopy Simulation}, journal = {Advanced Robotics}, year = {2012}, month = {9}, volume = {26}, number = {18}, pages = {2115-2143}, abstract = {This paper presents a new design and analysis of a haptic interface for a gastrointestinal endoscopy simulation. The gastrointestinal endoscopy is a procedure in which the digestive tract and organs of a patient are diagnosed and treated using a long and flexible endoscope. The developed haptic interface incorporates two degrees of freedom (DOF), each of which is necessary to describe the movements of an endoscope during the actual endoscopy procedures. The haptic interface has a translational motion mechanism to implement the insertion movement of the endoscope, and a rotational motion mechanism to implement the rotational movement of the endoscope. The endoscope included in the haptic interface is supported by a folding guide to prevent the endoscope from buckling. Force feedback in each direction is provided by wire-driven mechanisms. The developed haptic interface has a workspace, sensitivity, and maximum attainable force and torque enough to simulate the endoscopy procedures such as colonoscopy, upper GI (gastrointestinal) endoscopy, and endoscopic retrograde cholangiopancreatography (ERCP). The developed haptic interface is applied to implementation of a colonoscopy simulation. Performance including force bandwidth is evaluated through experiments and simulation.}, web_url = {http://www.tandfonline.com/doi/abs/10.1080/01691864.2012.703300}, state = {published}, DOI = {10.1080/01691864.2012.703300}, author = {Yu IS, Woo HS, Son HI{chakurt}{Department Human Perception, Cognition and Action}, Ahn W, Jung HR, Lee DY and Yi SY} } @Article{ BiegBBC2012, title = {Looking for Discriminating Is Different from Looking for Looking's Sake}, journal = {PLoS ONE}, year = {2012}, month = {9}, volume = {7}, number = {9}, pages = {1-9}, abstract = {Recent studies provide evidence for task-specific influences on saccadic eye movements. For instance, saccades exhibit higher peak velocity when the task requires coordinating eye and hand movements. The current study shows that the need to process task-relevant visual information at the saccade endpoint can be, in itself, sufficient to cause such effects. In this study, participants performed a visual discrimination task which required a saccade for successful completion. We compared the characteristics of these task-related saccades to those of classical target-elicited saccades, which required participants to fixate a visual target without performing a discrimination task. The results show that task-related saccades are faster and initiated earlier than target-elicited saccades. Differences between both saccade types are also noted in their saccade reaction time distributions and their main sequences, i.e., the relationship between saccade velocity, duration, and amplitude.}, web_url = {http://www.plosone.org/article/fetchObjectAttachment.action;jsessionid=409E420397B230BE376365245B458D2A?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0045445&representation=PDF}, state = {published}, DOI = {10.1371/journal.pone.0045445}, EPUB = {e45445}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Article{ GrauMoyaOB2012, title = {Risk-Sensitivity in Bayesian Sensorimotor Integration}, journal = {PLoS Computational Biology}, year = {2012}, month = {9}, volume = {8}, number = {9}, pages = {1-7}, abstract = {Information processing in the nervous system during sensorimotor tasks with inherent uncertainty has been shown to be consistent with Bayesian integration. Bayes optimal decision-makers are, however, risk-neutral in the sense that they weigh all possibilities based on prior expectation and sensory evidence when they choose the action with highest expected value. In contrast, risk-sensitive decision-makers are sensitive to model uncertainty and bias their decision-making processes when they do inference over unobserved variables. In particular, they allow deviations from their probabilistic model in cases where this model makes imprecise predictions. Here we test for risk-sensitivity in a sensorimotor integration task where subjects exhibit Bayesian information integration when they infer the position of a target from noisy sensory feedback. When introducing a cost associated with subjects' response, we found that subjects exhibited a characteristic bias towards low cost responses when their uncertainty was high. This result is in accordance with risk-sensitive decision-making processes that allow for deviations from Bayes optimal decision-making in the face of uncertainty. Our results suggest that both Bayesian integration and risk-sensitivity are important factors to understand sensorimotor integration in a quantitative fashion.}, web_url = {http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.1002698}, state = {published}, DOI = {10.1371/journal.pcbi.1002698}, EPUB = {e1002698}, author = {Grau-Moya J{jgrau}{Research Group Sensorimotor Learning and Decision-Making}, Ortega PA{portega}{Research Group Sensorimotor Learning and Decision-Making} and Braun DA{dbraun}{Research Group Sensorimotor Learning and Decision-Making}} } @Article{ FranchiSRBR2012, title = {Shared Control: Balancing Autonomy and Human Assistance with a Group of Quadrotor UAVs}, journal = {IEEE Robotics & Automation Magazine}, year = {2012}, month = {9}, volume = {19}, number = {3}, pages = {57-68}, abstract = {Robustness and flexibility constitute the main advantages of multiple-robot systems with respect to single-robot ones as per the recent literature. The use of multiple unmanned aerial vehicles (UAVs) combines these benefits with the agility and pervasiveness of aerial platforms [1], [2]. The degree of autonomy of the multi-UAV system should be tuned according to the specificities of the situation under consideration. For regular missions, fully autonomous UAV systems are often appropriate, but, in general, the use of semiautonomous groups of UAVs, supervised or partially controlled by one or more human operators, is the only viable solution to deal with the complexity and unpredictability of real-world scenarios as in, e.g., the case of search and rescue missions or exploration of large/cluttered environments [3]. In addition, the human presence is also mandatory for taking the responsibility of critical decisions in high-risk situations [4].}, file_url = {fileadmin/user_upload/files/publications/2012/2012f-FraSecRylBueRob-preprint_01.pdf}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6290692&contentType=Journals+%26+Magazines&sortType%3Dasc_p_Sequence%26filter%3DAND%28p_IS_Number%3A6299141%29}, state = {published}, DOI = {10.1109/MRA.2012.2205625}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}, Secchi C, Ryll M{maryll}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Article{ StreuberMBd2012, title = {The Influence of Visual Information on the Motor Control of Table Tennis Strokes}, journal = {Presence}, year = {2012}, month = {9}, volume = {21}, number = {3}, pages = {281-294}, abstract = {Theories of social interaction (i.e., common coding theory) suggest that visual information about the interaction partner is critical for successful interpersonal action coordination. Seeing the interaction partner allows an observer to understand and predict the interaction partner's behavior. However, it is unknown which of the many sources of visual information about an interaction partner (e.g., body, end effectors, and/or interaction objects) are used for action understanding and thus for the control of movements in response to observed actions. We used a novel immersive virtual environment to investigate this further. Specifically, we asked participants to perform table tennis strokes in response to table tennis balls stroked by a virtual table tennis player. We tested the effect of the visibility of the ball, the paddle, and the body of the virtual player on task performance and movement kinematics. Task performance was measured as the minimum distance between the center of the paddle and the center of the ball (radial error). Movement kinematics was measured as variability in the paddle speed of repeatedly executed table tennis strokes (stroke speed variability). We found that radial error was reduced when the ball was visible compared to invisible. However, seeing the body and/or the racket of the virtual players only reduced radial error when the ball was invisible. There was no influence of seeing the ball on stroke speed variability. However, we found that stroke speed variability was reduced when either the body or the paddle of the virtual player was visible. Importantly, the differences in stroke speed variability were largest in the moment when the virtual player hit the ball. This suggests that seeing the virtual player's body or paddle was important for preparing the stroke response. These results demonstrate for the first time that the online control of arm movements is coupled with visual body information about an opponent.}, web_url = {http://www.mitpressjournals.org/doi/abs/10.1162/PRES_a_00113}, state = {published}, DOI = {10.1162/PRES_a_00113}, author = {Streuber S{stst}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}} } @Article{ RoheWF2012, title = {Dissociation of BOLD responses to reward prediction errors and reward receipt by a model comparison}, journal = {European Journal of Neuroscience}, year = {2012}, month = {8}, volume = {36}, number = {3}, pages = {2376–2382}, abstract = {The representation of reward anticipation and reward prediction errors is the basis for reward-associated learning. The representation of whether or not a reward occurred (reward receipt) is important for decision making. Recent studies suggest that, while reward anticipation and reward prediction errors are encoded in the midbrain and the ventral striatum, reward receipts are encoded in the medial orbitofrontal cortex. In order to substantiate this functional specialization we analyzed data from an fMRI study in which 59 subjects completed two simple monetary reward paradigms. Because reward receipts and reward prediction errors were correlated, a statistical model comparison was applied separating the effects of the two. Reward prediction error fitted BOLD responses significantly better than reward receipt in the midbrain and the ventral striatum. Conversely, reward receipt fitted BOLD responses better in the orbitofrontal cortex. Activation related to reward anticipation was found in the orbitofrontal cortex. The results confirm a functional specialization of behaviorally important aspects of reward processing within the mesolimbic dopaminergic system.}, web_url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1460-9568.2012.08125.x/pdf}, state = {published}, DOI = {10.1111/j.1460-9568.2012.08125.x}, author = {Rohe T{trohe}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging}, Weber B and Fliessbach K} } @Article{ 6456, title = {Effect of Impedance-Shaping on Perception of Soft Tissues in Macro-Micro Teleoperation}, journal = {IEEE Transactions on Industrial Electronics}, year = {2012}, month = {8}, volume = {59}, number = {8}, pages = {3273-3285}, abstract = {This paper aims at analyzing the effect of widely known impedance-shaping control method on the perception of soft-tissues in tele-microsurgical applications. The generalized teleoperation control architecture has been modified to include the impedance-shaping term. New performance index has been defined based on the two proposed indices for the detection and the discrimination of the soft environments to analyze the effect of this modified control on the kinesthetic perception of soft-tissues. The effect is then theoretically analyzed on the conventional position-position, force-position, and four-channel control architectures based on the newly defined index. The effectiveness of this newly proposed kinesthetic perception index is also verified using psychophysics experiments. The theoretical analysis of the effects of the impedance-shaping method on the perception of soft tissues is then validated using the proposed index by experiments with phantom soft tissues for conventional teleoperation architectures.}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5759774}, state = {published}, DOI = {10.1109/TIE.2011.2148672}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Bhattacharjee T and Hashimoto H} } @Article{ GaissertWFB2012, title = {Haptic Categorical Perception of Shape}, journal = {PLoS One}, year = {2012}, month = {8}, volume = {7}, number = {8}, pages = {1-7}, abstract = {Categorization and categorical perception have been extensively studied, mainly in vision and audition. In the haptic domain, our ability to categorize objects has also been demonstrated in earlier studies. Here we show for the first time that categorical perception also occurs in haptic shape perception. We generated a continuum of complex shapes by morphing between two volumetric objects. Using similarity ratings and multidimensional scaling we ensured that participants could haptically discriminate all objects equally. Next, we performed classification and discrimination tasks. After a short training with the two shape categories, both tasks revealed categorical perception effects. Training leads to between-category expansion resulting in higher discriminability of physical differences between pairs of stimuli straddling the category boundary. Thus, even brief training can alter haptic representations of shape. This suggests that the weights attached to various haptic shape features can be changed dynamically in response to top-down information about class membership.}, web_url = {http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0043062}, state = {published}, DOI = {10.1371/journal.pone.0043062}, EPUB = {e43062}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action}, Waterkamp S{swaterka}{Department Human Perception, Cognition and Action}, Fleming RW{roland}{Department Human Perception, Cognition and Action} and B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Article{ ConradVN2012, title = {Interactions Between Apparent Motion Rivalry in Vision and Touch}, journal = {Psychological Science}, year = {2012}, month = {8}, volume = {23}, number = {8}, pages = {940-948}, abstract = {In multistable perception, the brain alternates between several perceptual explanations of ambiguous sensory signals. It is unknown whether multistable processes can interact across the senses. In the study reported here, we presented subjects with unisensory (visual or tactile), spatially congruent visuotactile, and spatially incongruent visuotactile apparent motion quartets. Congruent stimulation induced pronounced visuotactile interactions, as indicated by increased dominance times for both vision and touch, and an increased percentage bias for the percept already dominant under unisensory stimulation. Thus, the joint evidence from vision and touch stabilizes the more likely perceptual interpretation and thereby decelerates the rivalry dynamics. Yet the temporal dynamics depended also on subjects’ attentional focus and was generally slower for tactile than for visual reports. Our results support Bayesian approaches to perceptual inference, in which the probability of a perceptual interpretation is determined by combining visual, tactile, or visuotactile evidence with modality-specific priors that depend on subjects’ attentional focus. Critically, the specificity of visuotactile interactions for spatially congruent stimulation indicates multisensory rather than cognitive-bias mechanisms.}, web_url = {http://pss.sagepub.com/content/23/8/940.full.pdf+html}, state = {published}, DOI = {10.1177/0956797612438735}, author = {Conrad V{conrad}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}{Research Group Cognitive Neuroimaging}, Vitello MP{vitello}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Article{ SoykaRBB2011, title = {Modeling direction discrimination thresholds for yaw rotations around an earth-vertical axis for arbitrary motion profiles}, journal = {Experimental Brain Research}, year = {2012}, month = {7}, volume = {220}, number = {1}, pages = {89-99}, abstract = {Understanding the dynamics of vestibular perception is important, for example, for improving the realism of motion simulation and virtual reality environments or for diagnosing patients suffering from vestibular problems. Previous research has found a dependence of direction discrimination thresholds for rotational motions on the period length (inverse frequency) of a transient (single cycle) sinusoidal acceleration stimulus. However, self-motion is seldom purely sinusoidal, and up to now, no models have been proposed that take into account non-sinusoidal stimuli for rotational motions. In this work, the influence of both the period length and the specific time course of an inertial stimulus is investigated. Thresholds for three acceleration profile shapes (triangular, sinusoidal, and trapezoidal) were measured for three period lengths (0.3, 1.4, and 6.7 s) in ten participants. A two-alternative forced-choice discrimination task was used where participants had to judge if a yaw rotation around an earth-vertical axis was leftward or rightward. The peak velocity of the stimulus was varied, and the threshold was defined as the stimulus yielding 75 % correct answers. In accordance with previous research, thresholds decreased with shortening period length (from ~2 deg/s for 6.7 s to ~0.8 deg/s for 0.3 s). The peak velocity was the determining factor for discrimination: Different profiles with the same period length have similar velocity thresholds. These measurements were used to fit a novel model based on a description of the firing rate of semi-circular canal neurons. In accordance with previous research, the estimates of the model parameters suggest that velocity storage does not influence perceptual thresholds.}, web_url = {http://www.springerlink.com/content/h72677r65r8p3g0u/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-012-3120-x}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ BarnettCowanRB2012, title = {Persistent perceptual delay for head movement onset relative to auditory stimuli of different durations and rise times}, journal = {Experimental Brain Research}, year = {2012}, month = {7}, volume = {220}, number = {1}, pages = {41-50}, abstract = {The perception of simultaneity between auditory and vestibular information is crucially important for maintaining a coherent representation of the acoustic environment whenever the head moves. It has been recently reported, however, that despite having similar transduction latencies, vestibular stimuli are perceived significantly later than auditory stimuli when simultaneously generated. This suggests that perceptual latency of a head movement is longer than a co-occurring sound. However, these studies paired a vestibular stimulation of long duration (~1 s) and of a continuously changing temporal envelope with a brief (10–50 ms) sound pulse. In the present study, the stimuli were matched for temporal envelope duration and shape. Participants judged the temporal order of the two stimuli, the onset of an active head movement and the onset of brief (50 ms) or long (1,400 ms) sounds with a square- or raised-cosine-shaped envelope. Consistent with previous reports, head movement onset had to precede the onset of a brief sound by about 73 ms in order for the stimuli to be perceived as simultaneous. Head movements paired with long square sounds (~100 ms) were not significantly different than brief sounds. Surprisingly, head movements paired with long raised-cosine sound (~115 ms) had to be presented even earlier than brief stimuli. This additional lead time could not be accounted for by differences in the comparison stimulus characteristics (temporal envelope duration and shape). Rather, differences between sound conditions were found to be attributable to variability in the time for head movement to reach peak velocity: the head moved faster when paired with a brief sound. The persistent lead time required for vestibular stimulation provides further evidence that the perceptual latency of vestibular stimulation is greater than the other senses.}, web_url = {http://www.springerlink.com/content/2q0453017814jm13/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-012-3112-x}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Raeder SM{sophie13}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ McDonnellBB2012, title = {Render me Real? Investigating the Effect of Render Style on the Perception of Animated Virtual Humans}, journal = {ACM Transactions on Graphics}, year = {2012}, month = {7}, volume = {31}, number = {4: SIGGRAPH 2012 Conference Proceedings}, pages = {91: 1-11}, abstract = {The realistic depiction of lifelike virtual humans has been the goal of many movie makers in the last decade. Recently, films such as Tron: Legacy and The Curious Case of Benjamin Button have produced highly realistic characters. In the real-time domain, there is also a need to deliver realistic virtual characters, with the increase in popularity of interactive drama video games (such as L.A. Noire™ or Heavy Rain™). There have been mixed reactions from audiences to lifelike characters used in movies and games, with some saying that the increased realism highlights subtle imperfections, which can be disturbing. Some developers opt for a stylized rendering (such as cartoon-shading) to avoid a negative reaction [Thompson 2004]. In this paper, we investigate some of the consequences of choosing realistic or stylized rendering in order to provide guidelines for developers for creating appealing virtual characters. We conducted a series of psychophysical experiments to determine whether render style affects how virtual humans are perceived. Motion capture with synchronized eye-tracked data was used throughout to animate custom-made virtual model replicas of the captured actors.}, web_url = {http://s2012.siggraph.org/attendees/sessions/100-71}, state = {published}, DOI = {10.1145/2185520.2185587}, author = {McDonnell R, Breidt M{mbreidt}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ NethSEKBM2011_2, title = {Velocity-Dependent Dynamic Curvature Gain for Redirected Walking}, journal = {IEEE Transactions on Visualization and Computer Graphics}, year = {2012}, month = {7}, volume = {18}, number = {7}, pages = {1041-1052}, abstract = {Redirected walking techniques allow people to walk in a larger virtual space than the physical extents of the laboratory. We describe two experiments conducted to investigate human sensitivity to walking on a curved path and to validate a new redirected walking technique. In a psychophysical experiment, we found that sensitivity to walking on a curved path was significantly lower for slower walking speeds (radius of 10 m versus 22 m). In an applied study, we investigated the influence of a velocity-dependent dynamic gain controller and an avatar controller on the average distance that participants were able to freely walk before needing to be reoriented. The mean walked distance was significantly greater in the dynamic gain controller condition, as compared to the static controller (22 m versus 15 m). Our results demonstrate that perceptually motivated dynamic redirected walking techniques, in combination with reorientation techniques, allow for unaided exploration of a large virtual city model.}, file_url = {fileadmin/user_upload/files/publications/2011/TVCG_Neth_Manuscript_revised.pdf}, web_url = {http://www.computer.org/portal/web/csdl/doi/10.1109/TVCG.2011.275}, state = {published}, DOI = {10.1109/TVCG.2011.275}, author = {Neth CT{neth}{Department Human Perception, Cognition and Action}, Souman JL{souman}{Department Human Perception, Cognition and Action}, Engel D{engel}{Department Human Perception, Cognition and Action}, Kloos U, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Article{ RedcayKS2012, title = {Look at this: the neural correlates of initiating and responding to bids for joint attention}, journal = {Frontiers in Human Neuroscience}, year = {2012}, month = {6}, volume = {6}, number = {169}, pages = {1-14}, abstract = {When engaging in joint attention, one person directs another person's attention to an object (Initiating Joint Attention, IJA), and the second person's attention follows (Responding to Joint Attention, RJA). As such, joint attention must occur within the context of a social interaction. This ability is critical to language and social development; yet the neural bases for this pivotal skill remain understudied. This paucity of research is likely due to the challenge in acquiring functional MRI data during a naturalistic, contingent social interaction. To examine the neural bases of both IJA and RJA we implemented a dual-video set-up that allowed for a face-to-face interaction between subject and experimenter via video during fMRI data collection. In each trial, participants either followed the experimenter's gaze to a target (RJA) or cued the experimenter to look at the target (IJA). A control condition, solo attention (SA), was included in which the subject shifted gaze to a target while the experimenter closed her eyes. Block and event-related analyses were conducted and revealed common and distinct regions for IJA and RJA. Distinct regions included the ventromedial prefrontal cortex for RJA and intraparietal sulcus and middle frontal gyrus for IJA (as compared to SA). Conjunction analyses revealed overlap in the dorsal medial prefrontal cortex (dMPFC) and right posterior superior temporal sulcus (pSTS) for IJA and RJA (as compared to SA) for the event analyses. Functional connectivity analyses during a resting baseline suggest joint attention processes recruit distinct but interacting networks, including social-cognitive, voluntary attention orienting, and visual networks. This novel experimental set-up allowed for the identification of the neural bases of joint attention during a real-time interaction and findings suggest that whether one is the initiator or responder, the dMPFC and right pSTS, are selectively recruited during periods of joint attention.}, web_url = {http://www.frontiersin.org/Human_Neuroscience/10.3389/fnhum.2012.00169/abstract}, state = {published}, DOI = {10.3389/fnhum.2012.00169}, author = {Redcay E, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action} and Saxe R} } @Article{ ArmannB2011, title = {Male and female faces are only perceived categorically when linked to familiar identities – And when in doubt, he is a male}, journal = {Vision Research}, year = {2012}, month = {6}, volume = {63}, pages = {69–80}, abstract = {Categorical perception (CP) is a fundamental cognitive process that enables us to sort similar objects in the world into meaningful categories with clear boundaries between them. CP has been found for high-level stimuli like human faces, more precisely, for the perception of face identity, expression and ethnicity. For sex however, which represents another important and biologically relevant dimension of human faces, results have been equivocal so far. Here, we reinvestigate CP for sex using newly created face stimuli to control two factors that to our opinion might have influenced the results in earlier studies. Our new stimuli are (a) derived from single face identities, so that changes of sex are not confounded with changes of identity information, and (b) “normalized” in their degree of maleness and femaleness, to counteract natural variations of perceived masculinity and femininity of faces that might obstruct evidence of categorical perception. Despite careful normalization, we did not find evidence of CP for sex using classical test procedures, unless participants were specifically familiarized with the face identities before testing. These results support the single-route hypothesis, stating that sex and identity information in faces are not processed in parallel, in contrast to what was suggested in the classical Bruce and Young model of face perception. Besides, interestingly, our participants show a consistent bias, before and after perceptual normalization of the male–female range of the test morph continua, to judge faces as male rather than female.}, web_url = {http://www.sciencedirect.com/science/article/pii/S0042698912001496}, state = {published}, DOI = {10.1016/j.visres.2012.05.005}, author = {Armann R{armann}{Department Human Perception, Cognition and Action} and B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Article{ PasqualettiFB2011, title = {On Cooperative Patrolling: Optimal Trajectories, Complexity Analysis, and Approximation Algorithms}, journal = {IEEE Transaction on Robotics}, year = {2012}, month = {6}, volume = {28}, number = {3}, pages = {592-606}, abstract = {The subject of this paper is the patrolling of an environment with the aid of a team of autonomous agents. We consider both the design of open-loop trajectories with optimal properties and of distributed control laws converging to optimal trajectories. As performance criteria, the refresh time and the latency are considered, i.e., respectively, time gap between any two visits of the same region and the time necessary to inform every agent about an event occurred in the environment. We associate a graph with the environment, and we study separately the case of a chain, tree, and cyclic graph. For the case of chain graph, we first describe a minimum refresh time and latency team trajectory and propose a polynomial time algorithm for its computation. Then, we describe a distributed procedure that steers the robots toward an optimal trajectory. For the case of tree graph, a polynomial time algorithm is developed for the minimum refresh time problem, under the technical assumption of a constant number of robots involved in the patrolling task. Finally, we show that the design of a minimum refresh time trajectory for a cyclic graph is NP-hard, and we develop a constant factor approximation algorithm.}, file_url = {fileadmin/user_upload/files/publications/2012/2010f-FraPasBul-preprint.pdf}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6122514}, state = {published}, DOI = {10.1109/TRO.2011.2179580}, author = {Pasqualetti F, Franchi A{antonio}{Department Human Perception, Cognition and Action} and Bullo F} } @Article{ GraydonLTP2011, title = {Scared stiff: The influence of anxiety on the perception of action capabilities}, journal = {Cognition and Emotion}, year = {2012}, month = {6}, volume = {26}, number = {7}, pages = {1301-1315}, abstract = {Influences on the perception of affordances (i.e., opportunities for actions) have been primarily studied by manipulating the functional morphology of the body. However, affordances are not just determined by the functional morphology of the perceiver, but also by the physiological state of the perceiver. States of anxiety have been shown to lead to marked changes in individuals' physiological state and their behaviour. To assess the influence of emotional state on affordance perception, the perception of action capabilities in near space was examined after participants completed an anxiety-provoking task. Anxiety was induced immediately prior to tasks that assessed participants' perceived reaching ability in Experiment 1, grasping ability in Experiment 2, and the ability to pass their hands through apertures in Experiment 3. Results indicated that those participants who experienced changes in anxiety underestimated their reaching, grasping, and passing ability compared to non-anxious participants. In other words, anxious participants were more conservative in their estimations of their action capabilities. These results suggest that anxiety influences the perception for affordances in near space and are consistent with the notion that anxiety induces withdrawal behaviours.}, web_url = {http://www.tandfonline.com/doi/abs/10.1080/02699931.2012.667391}, state = {published}, DOI = {10.1080/02699931.2012.667391}, author = {Graydon M, Linkenauger SA{sally}{Department Human Perception, Cognition and Action}, Teachman B and Proffitt DR} } @Article{ ChuangVB2012_2, title = {Learned non-rigid object motion is a view-invariant cue to recognizing novel objects}, journal = {Frontiers in Computational Neuroscience}, year = {2012}, month = {5}, volume = {6}, number = {26}, pages = {1-8}, abstract = {There is evidence that observers use learned object motion to recognize objects. For instance, studies have shown that reversing the learned direction in which a rigid object rotated in depth impaired recognition accuracy. This motion reversal can be achieved by playing animation sequences of moving objects in reverse frame order. In the current study, we used this sequence-reversal manipulation to investigate whether observers encode the motion of dynamic objects in visual memory, and whether such dynamic representations are encoded in a way that is dependent on the viewing conditions. Participants first learned dynamic novel objects, presented as animation sequences. Following learning, they were then tested on their ability to recognize these learned objects when their animation sequence was shown in the same sequence order as during learning or in the reverse sequence order. In Experiment 1, we found that non-rigid motion contributed to recognition performance; that is, sequence-reversal decreased sensitivity across different tasks. In subsequent experiments, we tested the recognition of non-rigidly deforming (Experiment 2) and rigidly rotating (Experiment 3) objects across novel viewpoints. Recognition performance was affected by viewpoint changes for both experiments. Learned non-rigid motion continued to contribute to recognition performance and this benefit was the same across all viewpoint changes. By comparison, learned rigid motion did not contribute to recognition performance. These results suggest that non-rigid motion provides a source of information for recognizing dynamic objects, which is not affected by changes to viewpoint.}, web_url = {http://www.frontiersin.org/Journal/DownloadFile.ashx?pdf=1&FileId=%2062343&articleId=%2022441&Version=%201&ContentTypeId=21&FileName=%20fncom-06-00026.pdf}, state = {published}, DOI = {10.3389/fncom.2012.00026}, author = {Chuang LL{chuang}{Department Human Perception, Cognition and Action}, Vuong QC{qvuong}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ BarnettCowanMVTB2011, title = {MPI CyberMotion Simulator: Implementation of a Novel Motion Simulator to Investigate Multisensory Path Integration in Three Dimensions}, journal = {Journal of Visualized Experiments}, year = {2012}, month = {5}, volume = {63}, number = {5}, pages = {1-6}, abstract = {Path integration is a process in which self-motion is integrated over time to obtain an estimate of one's current position relative to a starting point 1. Humans can do path integration based exclusively on visual 2-3, auditory 4, or inertial cues 5. However, with multiple cues present, inertial cues - particularly kinaesthetic - seem to dominate 6-7. In the absence of vision, humans tend to overestimate short distances (<5 m) and turning angles (<30°), but underestimate longer ones 5. Movement through physical space therefore does not seem to be accurately represented by the brain. Extensive work has been done on evaluating path integration in the horizontal plane, but little is known about vertical movement (see 3 for virtual movement from vision alone). One reason for this is that traditional motion simulators have a small range of motion restricted mainly to the horizontal plane. Here we take advantage of a motion simulator 8-9 with a large range of motion to assess whether path integration is similar between horizontal and vertical planes. The relative contributions of inertial and visual cues for path navigation were also assessed. 16 observers sat upright in a seat mounted to the flange of a modified KUKA anthropomorphic robot arm. Sensory information was manipulated by providing visual (optic flow, limited lifetime star field), vestibular-kinaesthetic (passive self motion with eyes closed), or visual and vestibular-kinaesthetic motion cues. Movement trajectories in the horizontal, sagittal and frontal planes consisted of two segment lengths (1st: 0.4 m, 2nd: 1 m; ±0.24 m/s2 peak acceleration). The angle of the two segments was either 45° or 90°. Observers pointed back to their origin by moving an arrow that was superimposed on an avatar presented on the screen. Observers were more likely to underestimate angle size for movement in the horizontal plane compared to the vertical planes. In the frontal plane observers were more likely to overestimate angle size while there was no such bias in the sagittal plane. Finally, observers responded slower when answering based on vestibular-kinaesthetic information alone. Human path integration based on vestibular-kinaesthetic information alone thus takes longer than when visual information is present. That pointing is consistent with underestimating and overestimating the angle one has moved through in the horizontal and vertical planes respectively, suggests that the neural representation of self-motion through space is non-symmetrical which may relate to the fact that humans experience movement mostly within the horizontal plane.}, web_url = {http://www.jove.com/pdf/default.aspx?PDF=&ID=3436}, state = {published}, DOI = {10.3791/3436}, EPUB = {e3436}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Vidal M{vidal}{Department Human Perception, Cognition and Action}, Teufel H{teufel}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ CamposBB2012, title = {Multisensory integration in the estimation of walked distances}, journal = {Experimental Brain Research}, year = {2012}, month = {5}, volume = {218}, number = {4}, pages = {551-565}, abstract = {When walking through space, both dynamic visual information (optic flow) and body-based information (proprioceptive and vestibular) jointly specify the magnitude of distance travelled. While recent evidence has demonstrated the extent to which each of these cues can be used independently, less is known about how they are integrated when simultaneously present. Many studies have shown that sensory information is integrated using a weighted linear sum, yet little is known about whether this holds true for the integration of visual and body-based cues for travelled distance perception. In this study using Virtual Reality technologies, participants first travelled a predefined distance and subsequently matched this distance by adjusting an egocentric, in-depth target. The visual stimulus consisted of a long hallway and was presented in stereo via a head-mounted display. Body-based cues were provided either by walking in a fully tracked free-walking space (Exp. 1) or by being passively moved in a wheelchair (Exp. 2). Travelled distances were provided either through optic flow alone, body-based cues alone or through both cues combined. In the combined condition, visually specified distances were either congruent (1.0×) or incongruent (0.7× or 1.4×) with distances specified by body-based cues. Responses reflect a consistent combined effect of both visual and body-based information, with an overall higher influence of body-based cues when walking and a higher influence of visual cues during passive movement. When comparing the results of Experiments 1 and 2, it is clear that both proprioceptive and vestibular cues contribute to travelled distance estimates during walking. These observed results were effectively described using a basic linear weighting model.}, web_url = {http://www.springerlink.com/content/t37011l884450186/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-012-3048-1}, author = {Campos JL{camposjl}{Department Human Perception, Cognition and Action}, Butler JS{butler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ NolanBWFBR2011, title = {Neural correlates of oddball detection in self-motion heading: A high-density event-related potential study of vestibular integration}, journal = {Experimental Brain Research}, year = {2012}, month = {5}, volume = {219}, number = {1}, pages = {1-11}, abstract = {The perception of self-motion is a product of the integration of information from both visual and non-visual cues, to which the vestibular system is a central contributor. It is well documented that vestibular dysfunction leads to impaired movement and balance, dizziness and falls, and yet our knowledge of the neuronal processing of vestibular signals remains relatively sparse. In this study, high-density electroencephalographic recordings were deployed to investigate the neural processes associated with vestibular detection of changes in heading. To this end, a self-motion oddball paradigm was designed. Participants were translated linearly 7.8 cm on a motion platform using a one second motion profile, at a 45° angle leftward or rightward of straight ahead. These headings were presented with a stimulus probability of 80–20 %. Participants responded when they detected the infrequent direction change via button-press. Event-related potentials (ERPs) were calculated in response to the standard (80 %) and target (20 %) movement directions. Statistical parametric mapping showed that ERPs to standard and target movements differed significantly from 490 to 950 ms post-stimulus. Topographic analysis showed that this difference had a typical P3 topography. Individual participant bootstrap analysis revealed that 93.3 % of participants exhibited a clear P3 component. These results indicate that a perceived change in vestibular heading can readily elicit a P3 response, wholly similar to that evoked by oddball stimuli presented in other sensory modalities. This vestibular-evoked P3 response may provide a readily and robustly detectable objective measure for the evaluation of vestibular integrity in various disease models.}, web_url = {http://www.springerlink.com/content/a574525416v829w4/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-012-3059-y}, author = {Nolan H, Butler JS{butler}{Department Human Perception, Cognition and Action}, Whelan R, Foxe JJ, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Reilly RB} } @Article{ SonO2011, title = {Real-time automatic inspection of macro defects in in-line TFT fabrication process}, journal = {Proceedings of the Institution of Mechanical Engineering, Part E: Journal of Process Mechanical Engineering}, year = {2012}, month = {5}, volume = {226}, number = {2}, pages = {178-183}, abstract = {In this article, an automatic detection and judgement method for macro defects in thin film transistor (TFT) fabrication process is proposed using a high-resolution line charge-coupled device camera as a preliminary inspection method for TFT liquid crystal display (TFT-LCD) panel. Macro defects are classified primarily into four types. Relevant detection and judgement methods are then applied according to the type of macro defect using different criteria such as diffraction pattern shifts, just noticeable differences, and the gradient of inspection images. The proposed method is verified with industrial experiments. In the experiment, 559 TFT glasses are used, which are sampled among the glasses and were judged as PASS (i.e. non-killer-defected glass) in the TFT fabrication process by a conventional human inspection method, but were judged as REJECT (i.e. killer-defected glass) in the module process. All macro defects in the sampled glasses were detected and rejected in the TFT fabrication process using the proposed method.}, web_url = {http://pie.sagepub.com/content/226/2/178.full.pdf+html}, state = {published}, DOI = {10.1177/0954408911413194}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action} and Oh MH} } @Article{ WittLP2012, title = {Get Me Out of This Slump! Visual Illusions Improve Sports Performance}, journal = {Psychological Science}, year = {2012}, month = {4}, volume = {23}, number = {4}, pages = {397-399}, abstract = {One of the reasons we (the authors) enjoy going to live college basketball games is to watch the antics of the student section. We love watching the students’ creativity in trying to pump up the home team and distract the visiting team, especially during free throws. Such escapades made us question whether manipulating what athletes see can influence their subsequent performance. Perception is clearly important for performance. For instance, when athletes look directly at a target without moving their eyes around—a pattern known as the quiet eye—they are more successful in making free throws, putting, and performing a variety of other tasks (e.g., Vickers, 1996, 2007). The quiet eye might lead to more successful performance by focusing attention on targets, and helping athletes to ignore distractors. Additionally, the quiet eye might change the way targets look. Targets presented in the fovea look bigger than those in the periphery (Newsome, 1972), so the quiet eye might lead athletes to perceive targets as bigger. Misperceiving a target as bigger could influence performance in one of three ways. It could disrupt performance because the observer might aim for a location that does not correspond with the target. In this case, the misperception would result in worse performance. However, actions and explicit perceptions may not be influenced by illusions to the same degree (Goodale & Milner, 1992). That is, there may be dissociations between perceptions and visually guided actions such that illusions, which fool conscious perception, do not influence subsequent actions (e.g., Ganel, Tanzer, & Goodale, 2008). In this case, misperceiving a target as bigger would not affect performance. A final alternative is that misperceiving a target as bigger could enhance performance. Bigger targets feel as if they should be easier to hit, so people may feel more confident when aiming for a bigger target. Given that increased confidence improves performance (e.g., Woodman & Hardy, 2003), a perceptually bigger target may also lead to enhanced performance. Here, we report an experiment in which we tested these possibilities.}, web_url = {http://pss.sagepub.com/content/23/4/397.full.pdf+html}, state = {published}, DOI = {10.1177/0956797611428810}, author = {Witt JK, Linkenauger SA{sally}{Department Human Perception, Cognition and Action} and Proffitt DR} } @Article{ vonLassbergBCK2012, title = {Smooth Pursuit Eye Movement Adaptation in High Level Gymnasts}, journal = {Motor Control}, year = {2012}, month = {4}, volume = {16}, number = {2}, pages = {176-194}, abstract = {This study investigated long-term adaptations of smooth pursuit eye movement characteristics in high-level gymnasts and compared these responses to those of nonathletes. Gymnasts were selected because of their exceptional ability to spatially orient during fast, multiaxial whole body rotations. Participants were tested with standardized and supra-maximal sinusoidal smooth pursuit measurements. The results showed significantly higher gain values in top-level gymnasts, followed by young federal team gymnasts, followed by the nonathlete control group. By testing participants over the course of three years and also after periods of abstinence from training, changes to patterns of smooth pursuit over time are revealed. These results have interesting implications for understanding the characteristics of eye-movements in expert populations as well as understanding the general principles that underlie oculomotor adaptation.}, web_url = {http://journals.humankinetics.com/mc-current-issue/mc-volume-16-issue-2-april/smooth-pursuit-eye-movement-adaptation-in-high-level-gymnasts}, state = {published}, author = {von Lassberg C, Beykirch K{kab}{Department Human Perception, Cognition and Action}, Campos JL{camposjl}{Department Human Perception, Cognition and Action} and Krug J} } @Article{ GianiOBKPN2012, title = {Steady-state responses in MEG demonstrate information integration within but not across the auditory and visual senses}, journal = {NeuroImage}, year = {2012}, month = {4}, volume = {60}, number = {2}, pages = {1478–1489}, abstract = {To form a unified percept of our environment, the human brain integrates information within and across the senses. This MEG study investigated interactions within and between sensory modalities using a frequency analysis of steady-state responses that are elicited time-locked to periodically modulated stimuli. Critically, in the frequency domain, interactions between sensory signals are indexed by crossmodulation terms (i.e. the sums and differences of the fundamental frequencies). The 3x2 factorial design, manipulated (1) modality: auditory, visual or audiovisual (2) steady-state modulation: the auditory and visual signals were modulated only in one sensory feature (e.g. visual gratings modulated in luminance at 6 Hz) or in two features (e.g. tones modulated in frequency at 40 Hz & amplitude at 0.2 Hz). This design enabled us to investigate crossmodulation frequencies that are elicited when two stimulus features are modulated concurrently (i) in one sensory modality or (ii) in auditory and visual modalities. In support of within-modality integration, we reliably identified crossmodulation frequencies when two stimulus features in one sensory modality were modulated at different frequencies. In contrast, no crossmodulation frequencies were identified when information needed to be combined from auditory and visual modalities. The absence of audiovisual crossmodulation frequencies suggests that the previously reported audiovisual interactions in primary sensory areas may mediate low level spatiotemporal coincidence detection that is prominent for stimulus transients but less relevant for sustained SSR responses. In conclusion, our results indicate that information in SSRs is integrated over multiple time scales within but not across sensory modalities at the primary cortical level.}, web_url = {http://www.sciencedirect.com/science/article/pii/S1053811912001322}, state = {published}, DOI = {10.1016/j.neuroimage.2012.01.114}, author = {Giani AS{giani}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging}, Ortiz EB, Belardinelli P, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}, Preissl H and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Article{ FischerLBB2011, title = {Visual Motion Responses in the Posterior Cingulate Sulcus: A Comparison to V5/MT and MST}, journal = {Cerebral Cortex}, year = {2012}, month = {4}, volume = {22}, number = {4}, pages = {865-876}, abstract = {Motion processing regions apart from V5+/MT+ are still relatively poorly understood. Here, we used functional magnetic resonance imaging to perform a detailed functional analysis of the recently described cingulate sulcus visual area (CSv) in the dorsal posterior cingulate cortex. We used distinct types of visual motion stimuli to compare CSv with V5/MT and MST, including a visual pursuit paradigm. Both V5/MT and MST preferred 3D flow over 2D planar motion, responded less yet substantially to random motion, had a strong preference for contralateral versus ipsilateral stimulation, and responded nearly equally to contralateral and to full-field stimuli. In contrast, CSv had a pronounced preference to 2D planar motion over 3D flow, did not respond to random motion, had a weak and nonsignificant lateralization that was significantly smaller than that of MST, and strongly preferred full-field over contralateral stimuli. In addition, CSv had a better capability to integrate eye movements with retinal motion compared with V5/MT and MST. CSv thus differs from V5+/MT+ by its unique preference to full-field, coherent, and planar motion cues. These results place CSv in a good position to process visual cues related to self-induced motion, in particular those associated to eye or lateral head movements.}, web_url = {http://cercor.oxfordjournals.org/content/22/4/865.full.pdf+html}, state = {published}, DOI = {10.1093/cercor/bhr154}, author = {Fischer E{efischer}{Department Physiology of Cognitive Processes}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Bartels A{abartels}{Department Physiology of Cognitive Processes}} } @Article{ FischerBLB2012, title = {Human Areas V3A and V6 Compensate for Self-Induced Planar Visual Motion}, journal = {Neuron}, year = {2012}, month = {3}, volume = {73}, number = {6}, pages = {1228-1240}, abstract = {Little is known about mechanisms mediating a stable perception of the world during pursuit eye movements. Here, we used fMRI to determine to what extent human motion-responsive areas integrate planar retinal motion with nonretinal eye movement signals in order to discard self-induced planar retinal motion and to respond to objective (“real”) motion. In contrast to other areas, V3A lacked responses to self-induced planar retinal motion but responded strongly to head-centered motion, even when retinally canceled by pursuit. This indicates a near-complete multimodal integration of visual with nonvisual planar motion signals in V3A. V3A could be mapped selectively and robustly in every single subject on this basis. V6 also reported head-centered planar motion, even when 3D flow was added to it, but was suppressed by retinal planar motion. These findings suggest a dominant contribution of human areas V3A and V6 to head-centered motion perception and to perceptual stability during eye movements.}, web_url = {http://www.sciencedirect.com/science/article/pii/S0896627312001407}, state = {published}, DOI = {10.1016/j.neuron.2012.01.022}, author = {Fischer E{efischer}{Department Physiology of Cognitive Processes}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes} and Bartels A{abartels}{Department Physiology of Cognitive Processes}} } @Article{ MachullaDFE2011, title = {Multisensory simultaneity recalibration: storage of the aftereffect in the absence of counterevidence}, journal = {Experimental Brain Research}, year = {2012}, month = {3}, volume = {217}, number = {1}, pages = {89-97}, abstract = {Recent studies show that repeated exposure to an asynchrony between auditory and visual stimuli shifts the point of subjective simultaneity. Usually, the measurement stimuli used to assess this aftereffect are interleaved with short re-exposures to the asynchrony. In a first experiment, we show that the aftereffect declines during measurement in spite of the use of re-exposures. In a second experiment, we investigate whether the observed decline is either due to a dissipation of the aftereffect with the passage of time, or the result of using measurement stimuli with a distribution of asynchronies different from the exposure stimulus. To this end, we introduced a delay before measuring the aftereffects and we compared the magnitude of the aftereffect with and without delay. We find that the aftereffect does not dissipate during the delay but instead is stored until new sensory information in the form of measurement stimuli is presented as counterevidence (i.e., stimuli with an asynchrony that differs from the one used during exposure).}, web_url = {http://www.springerlink.com/content/u7337tv890047w92/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-011-2976-5}, author = {Machulla TK{tonja}{Research Group Multisensory Perception and Action}, Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Fr\"ohlich E{efroehl}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Article{ KaulardCBW2012, title = {The MPI Facial Expression Database: A Validated Database of Emotional and Conversational Facial Expressions}, journal = {PLoS One}, year = {2012}, month = {3}, volume = {7}, number = {3}, pages = {1-18}, abstract = {The ability to communicate is one of the core aspects of human life. For this, we use not only verbal but also nonverbal signals of remarkable complexity. Among the latter, facial expressions belong to the most important information channels. Despite the large variety of facial expressions we use in daily life, research on facial expressions has so far mostly focused on the emotional aspect. Consequently, most databases of facial expressions available to the research community also include only emotional expressions, neglecting the largely unexplored aspect of conversational expressions. To fill this gap, we present the MPI facial expression database, which contains a large variety of natural emotional and conversational expressions. The database contains 55 different facial expressions performed by 19 German participants. Expressions were elicited with the help of a method-acting protocol, which guarantees both well-defined and natural facial expressions. The method-acting protocol was based on every-day scenarios, which are used to define the necessary context information for each expression. All facial expressions are available in three repetitions, in two intensities, as well as from three different camera angles. A detailed frame annotation is provided, from which a dynamic and a static version of the database have been created. In addition to describing the database in detail, we also present the results of an experiment with two conditions that serve to validate the context scenarios as well as the naturalness and recognizability of the video sequences. Our results provide clear evidence that conversational expressions can be recognized surprisingly well from visual information alone. The MPI facial expression database will enable researchers from different research fields (including the perceptual and cognitive sciences, but also affective computing, as well as computer vision) to investigate the processing of a wider range of natural facial expressions.}, web_url = {http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0032321}, state = {published}, DOI = {10.1371/journal.pone.0032321}, EPUB = {e32321}, author = {Kaulard K{kascot}{Department Human Perception, Cognition and Action}, Cunningham DW{dwc}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Article{ FrankensteinMBM2011, title = {Is the Map in Our Head Oriented North?}, journal = {Psychological Science}, year = {2012}, month = {2}, volume = {23}, number = {2}, pages = {120-125}, abstract = {We examined how a highly familiar environmental space—one’s city of residence—is represented in memory. Twenty-six participants faced a photo-realistic virtual model of their hometown and completed a task in which they pointed to familiar target locations from various orientations. Each participant’s performance was most accurate when he or she was facing north, and errors increased as participants’ deviation from a north-facing orientation increased. Pointing errors and latencies were not related to the distance between participants’ initial locations and the target locations. Our results are inconsistent with accounts of orientation-free memory and with theories assuming that the storage of spatial knowledge depends on local reference frames. Although participants recognized familiar local views in their initial locations, their strategy for pointing relied on a single, north-oriented reference frame that was likely acquired from maps rather than experience from daily exploration. Even though participants had spent significantly more time navigating the city than looking at maps, their pointing behavior seemed to rely on a north-oriented mental map.}, web_url = {http://pss.sagepub.com/content/23/2/120.full.pdf+html}, state = {published}, DOI = {10.1177/0956797611429467}, author = {Frankenstein J{frankenstein}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Meilinger T{meilinger}{Department Human Perception, Cognition and Action}} } @Article{ GaissertW2011_2, title = {Categorizing natural objects: a comparison of the visual and the haptic modalities}, journal = {Experimental Brain Research}, year = {2012}, month = {1}, volume = {216}, number = {1}, pages = {123-134}, abstract = {Although the hands are the most important tool for humans to manipulate objects, only little is known about haptic processing of natural objects. Here, we selected a unique set of natural objects, namely seashells, which vary along a variety of object features, while others are shared across all stimuli. To correctly interact with objects, they have to be identified or categorized. For both processes, measuring similarities between objects is crucial. Our goal is to better understand the haptic similarity percept by comparing it to the visual similarity percept. First, direct similarity measures were analyzed using multidimensional scaling techniques to visualize the perceptual spaces of both modalities. We find that the visual and the haptic modality form almost identical perceptual spaces. Next, we performed three different categorization tasks. All tasks exhibit a highly accurate processing of complex shapes of the haptic modality. Moreover, we find that objects grouped into the same category form regions within the perceptual space. Hence, in both modalities, perceived similarity constitutes the basis for categorizing objects. Moreover, both modalities focus on shape to form categories. Taken together, our results lead to the assumption that the same cognitive processes link haptic and visual similarity perception and the resulting categorization behavior.}, web_url = {http://www.springerlink.com/content/h8174v8813827266/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-011-2916-4}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Article{ DurhamFB2011, title = {Distributed pursuit-evasion without mapping or global localization via local frontiers}, journal = {Autonomous Robots}, year = {2012}, month = {1}, volume = {32}, number = {1}, pages = {81-95}, abstract = {This paper addresses a visibility-based pursuit-evasion problem in which a team of mobile robots with limited sensing and communication capabilities must coordinate to detect any evaders in an unknown, multiply-connected planar environment. Our distributed algorithm to guarantee evader detection is built around maintaining complete coverage of the frontier between cleared and contaminated regions while expanding the cleared region. We detail a novel distributed method for storing and updating this frontier without building a map of the environment or requiring global localization. We demonstrate the functionality of the algorithm through simulations in realistic environments and through hardware experiments. We also compare Monte Carlo results for our algorithm to the theoretical optimum area cleared as a function of the number of robots available.}, file_url = {fileadmin/user_upload/files/publications/2012/2011c-DurFraBul-preprint.pdf}, web_url = {http://www.springerlink.com/content/a02pr41790ll754w/fulltext.pdf}, state = {published}, DOI = {10.1007/s10514-011-9260-1}, author = {Durham JW, Franchi A{antonio}{Department Human Perception, Cognition and Action} and Bullo F} } @Article{ 4958, title = {From Isovists via Mental Representations to Behaviour: First Steps Toward Closing the Causal Chain}, journal = {Environment and Planning B: Planning and Design}, year = {2012}, month = {1}, volume = {39}, number = {1}, pages = {48-62}, abstract = {This paper addresses the interactions between human wayfinding performance, the mental representation of routes, and the geometrical layout of path intersections. The conclusions of this paper are based on the results of a virtual reality empirical experiment. The study consisted of a route-learning and reproduction task and two choice reaction tasks measuring the acquired knowledge of route decision points. In order to relate the recorded behaviour to the geometry of the environment, a specific adaptation of an isovist-based spatial analysis that accounts for directional bias in human spatial perception and representation was developed. The analyses applied provided conclusive evidence of correspondences between the geometrical properties of environments as captured by isovists and their mental representations.}, web_url = {http://www.envplan.com/epb/fulltext/b39/b34048t.pdf}, state = {published}, DOI = {10.1068/b34048t}, author = {Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Franz G{gf}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ DopjansBW2012, title = {Serial exploration of faces: Comparing vision and touch}, journal = {Journal of Vision}, year = {2012}, month = {1}, volume = {12}, number = {1:6}, pages = {1-14}, abstract = {Even though we can recognize faces by touch surprisingly well, haptic face recognition performance is still worse than for visual exploration. One possibility for this performance difference might be due to different encoding strategies in the two modalities, namely, holistic encoding in vision versus serial encoding in haptics. Here, we tested this hypothesis by promoting serial encoding in vision, using a novel, gaze-restricted display that limited the effective field of view in vision to resemble that of haptic exploration. First, we compared haptic with gaze-restricted and unrestricted visual face recognition. Second, we used the face inversion paradigm to assess how encoding differences might affect processing strategies (featural vs. holistic). By promoting serial encoding in vision, we found equal face recognition performance in vision and haptics with a clear switch from holistic to featural processing, suggesting that performance differences in visual and haptic face recognition are due to modality-specific encoding strategies.}, web_url = {http://www.journalofvision.org/content/12/1/6.full.pdf+html}, state = {published}, DOI = {10.1167/12.1.6}, author = {Dopjans L{ldopjans}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Inproceedings{ OrtegaGGBB2012, title = {A Nonparametric Conjugate Prior Distribution for the Maximizing Argument of a Noisy Function}, year = {2012}, month = {12}, pages = {3014-3022}, abstract = {We propose a novel Bayesian approach to solve stochastic optimization problems that involve finding extrema of noisy, nonlinear functions. Previous work has focused on representing possible functions explicitly, which leads to a two-step procedure of first, doing inference over the function space and second, finding the extrema of these functions. Here we skip the representation step and directly model the distribution over extrema. To this end, we devise a non-parametric conjugate prior where the natural parameter corresponds to a given kernel function and the sufficient statistic is composed of the observed function values. The resulting posterior distribution directly captures the uncertainty over the maximum of the unknown function.}, file_url = {fileadmin/user_upload/files/publications/2012/NIPS-2012-Ortega.pdf}, web_url = {http://nips.cc/Conferences/2012/}, editor = {Bartlett, P. , F.C.N. Pereira, L. Bottou, C.J.C. Burges, K.Q. Weinberger}, booktitle = {Advances in Neural Information Processing Systems 25}, event_name = {Twenty-Sixth Annual Conference on Neural Information Processing Systems (NIPS 2012)}, event_place = {Lake Tahoe, NV, USA}, state = {published}, author = {Ortega PA{portega}{Research Group Sensorimotor Learning and Decision-Making}, Grau-Moya J{jgrau}{Research Group Sensorimotor Learning and Decision-Making}, Genewein T{tgenewein}{Research Group Sensorimotor Learning and Decision-Making}, Balduzzi D{balduzzi}{Department Empirical Inference} and Braun DA{dbraun}{Research Group Sensorimotor Learning and Decision-Making}} } @Inproceedings{ FranchiR2012, title = {Decentralized Control of Parallel Rigid Formations with Direction Constraints and Bearing Measurements}, year = {2012}, month = {12}, pages = {5310-5317}, abstract = {In this paper we analyze the relationship between scalability, minimality and rigidity, and its application to cooperative control. As a case study, we address the problem of multi-agent formation control by proposing a distributed control strategy that stabilizes a formation described with bearing (direction) constraints, and that only requires bearing measurements and parallel rigidity of the interaction graph. We also consider the possibility of having different graphs modeling the interaction network in order to explicitly take into account the conceptual difference between sensing, communication, control, and parameters stored in the network. We then show how the information can be ‘moved’ from a graph to another making use of decentralized estimation, provided the parallel rigidity property. Finally we present simulative examples in order to show the validity of the theoretical analysis in some illustrative cases.}, file_url = {fileadmin/user_upload/files/publications/2012/2012i-FraRob-preprint.pdf}, web_url = {http://control.disp.uniroma2.it/cdc2012/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {51th IEEE Conference on Decision and Control (CDC 2012)}, event_place = {Maui, HI, USA}, state = {published}, ISBN = {978-1-4673-2065-8}, DOI = {10.1109/CDC.2012.6426034}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ LacheleFBR2012, title = {SwarmSimX: Real-time Simulation Environment for Multi-robot Systems}, year = {2012}, month = {11}, pages = {375-387}, abstract = {In this paper we present a novel simulation environment called SwarmSimX with the ability to simulate dozens of robots in a realistic 3D environment. The software architecture of SwarmSimX allows new robots, sensors, and other libraries to be loaded at runtime, extending the functionality of the simulation environment significantly. In addition, SwarmSimX allows an easy exchange of the underlying libraries used for the visual and physical simulation to incorporate different libraries (e.g., improved or future versions). A major feature is also the possibility to perform the whole simulation in real-time allowing for human-in-the-loop or hardware-in-the-loop scenarios. SwarmSimX has been already employed in several works presenting haptic shared control of multiple mobile robots (e.g., quadrotor UAVs). Additionally, we present here two validation tests showing the physical fidelity and the real-time performance of SwarmSimX. For the tests we used NVIDIA® PhysX® and Ogre3D as physics and rendering libraries, respectively.}, file_url = {fileadmin/user_upload/files/publications/2012/2012m-LaeFraBueRob-preprint.pdf}, web_url = {http://www.2012.simpar.org/}, editor = {Noda, I. , N. Ando, D. Brugali, J.J. Kuffner}, publisher = {Springer}, address = {Berlin, Germany}, booktitle = {Simulation, Modeling, and Programming for Autonomous Robots}, event_name = {3rd International Conference on Simulation, Modeling, and Programming for Autonomous Robots (SIMPAR 2012)}, event_place = {Tsukuba, Japan}, state = {published}, ISBN = {978-3-642-34326-1}, DOI = {10.1007/978-3-642-34327-8_34}, author = {L\"achele J{siddian}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ FranchiMR2012, title = {A Synergetic High-level/Reactive Planning Framework with Application to Human-Assisted Navigation}, year = {2012}, month = {10}, pages = {15-20}, abstract = {In this work we present a novel framework for the systematic integration of high-level/mission schedulers, middlelevel/cognitive-enabled online-planners and low-level/reactive trajectory modifiers. The approach does not rely on a particular parametrization of the trajectory and assumes a basic environment representation. As an application, the online capabilities of the method can be used to let a mobile robot cooperate with a human taking the role of the middle-level planner. In that case we also describe a rigorous way to bilaterally couple the human and the reactive planner in order to provide an immersive haptic feeling of the planner state. Hardware/Human in-the-loop simulations, with a quadrotor UAV used as robotic platform and a real haptic instrument, are provided as validating showcase of the presented theoretical framework.}, file_url = {fileadmin/user_upload/files/publications/2012/2012o-FraMasRob-preprint.pdf}, web_url = {http://cs.stanford.edu/people/tkr/iros2012/proceedings.php}, editor = {Kroeger, T. , C. Guarino Lo Bianco}, event_name = {2012 IEEE IROS Workshop on Robot Motion Planning: Online, Reactive, and in Real-time}, event_place = {Vilamoura, Portugal}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}, Masone C{masone}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ SpicaFOBR2012, title = {Aerial Grasping of a Moving Target with a Quadrotor UAV}, year = {2012}, month = {10}, pages = {4985-4992}, abstract = {Abstract—For a quadrotor aircraft, we study the problem of planning a trajectory that connects two arbitrary states while allowing the UAV to grasp a moving target at some intermediate time. To this end, two classes of canonical grasping maneuvers are defined and characterized. A planning strategy relying on differential flatness is then proposed to concatenate one or more grasping maneuvers by means of spline-based subtrajectories, with the additional objective of minimizing the total transfer time. The proposed planning algorithm is not restricted to pure hovering-to-hovering motions and takes into account practical constraints, such as the finite duration of the grasping phase. The effectiveness of the proposed approach is shown by means of physically-based simulations.}, file_url = {fileadmin/user_upload/files/publications/2012/IROS-2012-Spica.pdf}, web_url = {http://www.iros2012.org/site/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2012)}, event_place = {Vilamoura, Portugal}, state = {published}, ISBN = {978-1-4673-1737-5}, DOI = {10.1109/IROS.2012.6385771}, author = {Spica R{rspica}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Oriolo G, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ SonHBL2012, title = {Effects of imperfect communication network on haptic teleoperator's performance}, year = {2012}, month = {10}, pages = {1772-1777}, abstract = {There is, practically, imperfect communication network (e.g., time delay and packet loss/switching) in haptic interaction (or teleoperation) systems. It is well known that such imperfect communication degrades teleoperator's performance as well as stability. We hypothesis that as an imperfectness level in the communication network is increasing, the teleoperator's performance is decreasing monotonically. In this paper, we verified the hypothesis via a human-centered evaluation of the teleoperator's perceptual performance in terms of just noticeable difference (JND), point of subject equality (PSE), and perception time using two psychophysical experiments: experiment of packet separation time and experiment of packet loss. In the experiment of packet separation time, there were significant increases of JND and PSE as the packet separation time was increased. However, interestingly, there was no significant decrease of teleoperator's perceptual performance in the experiment of packet loss although the packet loss rate was increased until 75 %. The experimental results clearly shows that the packet separation time affects on the teleoperator's perceptual performance more than the packet loss rate.}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=06393131}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {12th International Conference on Control, Automation and Systems (ICCAS 2012)}, event_place = {Jeje, South Korea}, state = {published}, ISBN = {978-1-4673-2247-8}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Hong A{ahong}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Lee D} } @Inproceedings{ HongCL2012, title = {H∞ Control of Bilateral Telesurgical Systems with Communication Constraints}, year = {2012}, month = {10}, pages = {1762-1767}, abstract = {Telesurgery has come to the forefront because of many merits such as a small incision, less bleeding and a short period of hospitalization. By means of internet, telesurgery is practical even the master and the slave are not physically in the same place. Internet, however, causes communication constraints such as time-varying delay and packet loss which induce instability and performance degradations in teleoperation systems. In this paper, we consider teleoperation systems including bilateral communications with asynchronous packet loss and time-varying delay. We define teleoperation sytsems as polytopic linear differential inclusions (PLDIs) to cope with switchings between subsystems which are divided by the status of communication channels. A sufficient condition which guarantees asymptotic stability and H_\infty performance is derived for teleoperation systems modeled as PLDIs. Then, we propose a H_\infty control design method, using linear matrix inequalities (LMIs).}, web_url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6393129&tag=1}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {12th International Conference on Control, Automation and Systems (ICCAS 2012)}, event_place = {Jeje, South Korea}, state = {published}, ISBN = {978-1-4673-2247-8}, author = {Hong A{ahong}{Department Human Perception, Cognition and Action}, Cho JH and Lee DY} } @Inproceedings{ VenrooijMvAvMB2012, title = {How effective is an armrest in mitigating biodynamic feedthrough?}, year = {2012}, month = {10}, pages = {2150-2155}, abstract = {Biodynamic feedthrough (BDFT) refers to a phenomenon where vehicle accelerations feed through the human body, causing involuntary limb motions, which may cause involuntary control inputs. Many studies have been devoted to mitigating BDFT effects. In the current paper, the effectiveness of a simple, cheap and widely-used hardware component is studied: the armrest. An experiment was conducted in which the BDFT dynamics were measured with and without armrest for different levels of neuromuscular admittance (i.e., different settings of the limb dynamics). The results show that the effect of the armrest on BDFT dynamics varies, both with frequency and neuromuscular admittance.}, web_url = {http://www.smc2012.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Systems, Man, and Cybernetics (SMC 2012)}, event_place = {Seoul, South Korea}, state = {published}, ISBN = {978-1-4673-1713-9}, DOI = {10.1109/ICSMC.2012.6378058}, author = {Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}, Mulder M, van Paassen MM, Abbink DA, van der Helm VCT, M Mulder and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ DropPDVM2012_2, title = {Identification of the Transition from Compensatory to Feedforward Behavior in Manual Control}, year = {2012}, month = {10}, pages = {2008-2013}, abstract = {The human in manual control of a dynamical system can use both feedback and feedforward control strategies and will select a strategy based on performance and required effort. Literature has shown that feedforward control is used during tracking tasks in response to predictable targets. The influence of an external disturbance signal on the utilization of a feedforward control strategy has never been investigated, however. We hypothesized that the human will use a combined feedforward and feedback control strategy whenever the predictable target signal is sufficiently strong, and a predominantly feedback strategy whenever the random disturbance signal is dominant. From the data of a human-in-the-loop experiment we conclude that feedforward control is used in all the considered experimental conditions, including those where the disturbance signal is dominant and feedforward control does not deliver a marked performance advantage.}, web_url = {http://www.smc2012.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Systems, Man, and Cybernetics (SMC 2012)}, event_place = {Seoul, South Korea}, state = {published}, ISBN = {978-1-4673-1713-9}, DOI = {10.1109/ICSMC.2012.6378033}, author = {Drop FM{fdrop}{Department Human Perception, Cognition and Action}, Pool DM{dpool}{Department Human Perception, Cognition and Action}, Damveld HJ, van Paassen MM, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mulder M} } @Inproceedings{ MasoneFBR2012, title = {Interactive Planning of Persistent Trajectories for Human-Assisted Navigation of Mobile Robots}, year = {2012}, month = {10}, pages = {2641-2648}, abstract = {This work extends the framework of bilateral shared control of mobile robots with the aim of increasing the robot autonomy and decreasing the operator commitment. We consider persistent autonomous behaviors where a cyclic motion must be executed by the robot. The human operator is in charge of modifying online some geometric properties of the desired path. This is then autonomously processed by the robot in order to produce an actual path guaranteeing: i) tracking feasibility, ii) collision avoidance with obstacles, iii) closeness to the desired path set by the human operator, and iv) proximity to some points of interest. A force feedback is implemented to inform the human operator of the global deformation of the path rather than using the classical mismatch between desired and executed motion commands. Physically-based simulations, with human/hardware-in-the-loop and a quadrotor UAV as robotic platform, demonstrate the feasibility of the method.}, file_url = {fileadmin/user_upload/files/publications/2012/IROS-2012-Masone.pdf}, web_url = {http://www.iros2012.org/site/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2012)}, event_place = {Vilamoura, Portugal}, state = {published}, ISBN = {978-1-4673-1737-5}, DOI = {10.1109/IROS.2012.6386171}, author = {Masone C{masone}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano R{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ RiedelFBR2012, title = {Intercontinental haptic control and advanced supervisory interfaces for groups of multiple UAVs}, year = {2012}, month = {10}, pages = {-}, file_url = {fileadmin/user_upload/files/publications/2012/HFR-2012-Riedel.pdf}, web_url = {http://hfr2012.wordpress.com/}, event_name = {5th Workshop for Young Researchers on Human-Friendly Robotics (HFR 2012)}, event_place = {Bruxelles, Belgium}, state = {published}, author = {Riedel M{mriedel}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ GrabeBR2012, title = {Robust Optical-Flow Based Self-Motion Estimation for a Quadrotor UAV}, year = {2012}, month = {10}, pages = {2153-2159}, abstract = {Robotic vision has become an important field of research for micro aerial vehicles in the recent years. While many approaches for autonomous visual control of such vehicles rely on powerful ground stations, the increasing availability of small and light hardware allows for the design of more independent systems. In this context, we present a robust algorithm able to recover the UAV ego-motion using a monocular camera and on-board hardware. Our method exploits the continuous homography constraint so as to discriminate among the observed feature points in order to classify those belonging to the dominant plane in the scene. Extensive experiments on a real quadrotor UAV demonstrate that the estimation of the scaled linear velocity in a cluttered environment improved by a factor of 25% compared to previous approaches.}, file_url = {fileadmin/user_upload/files/publications/2012/IROS-2012-Grabe.pdf}, web_url = {http://www.iros2012.org/site/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2012)}, event_place = {Vilamoura, Portugal}, state = {published}, ISBN = {978-1-4673-1737-5}, DOI = {10.1109/IROS.2012.6386234}, author = {Grabe V{vgrabe}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ MasoneFBR2012_2, title = {Shared trajectory planning for human-in-the-loop navigation of mobile robots in cluttered environments}, year = {2012}, month = {10}, pages = {-}, abstract = {The advances made in the last two decades have allowed robotic platforms, and in particular mobile robots, to successfully address a large variety of tasks, albeit mainly repetitive and simple ones. However, real-world applications typically involve complex decision making processes and non structured environments thus requiring a level of perception/world awareness and cognitive capabilities that cannot yet be provided by a robot. For this reason it is convenient, if not mandatory, to have a human supervising the execution. The robot shared control framework (see, e.g., [1], [2]) represents a promising step in this direction, since it allows to merge robots (limited) autonomy and humans cognitive capabilities. Previous studies have applied this idea to mobile robots navigating in cluttered environments, with an emphasis on bilateral shared control architectures with haptic feedback for the human operator. Typically, the operator commands a motion (desired position, reference velocity) to the robot via a haptic device. The robot executes the command while retaining some autonomy in order to, e.g., avoid obstacles or other dangers. Finally, the loop is closed by rendering on the haptic feedback a force that is proportional to the mismatch between commanded and executed motion in order to increase the operator’s situational awareness. Despite being an effective approach, commanding direct motion inputs requires a high commitment of the human, especially when the task is very complex or the environment is highly cluttered. Therefore, we propose an extension to the shared control in which an operator acts at the planning level, in order to modify some characteristics of the task but without the burden of directly driving the robot [3]. We assume that a task scheduler generates an initial trajectory based only on prior information. The trajectory is described as i) a geometric path controls to the set of parameters x, allowing the user to command some global behavior, e.g. translations or rotations of the curve. At the same time, the robot must track the generated trajectory and, whenever needed, modify it in real time in order to avoid collisions or to reach a nearby target. In particular, the robot performs both a reactive deformation of the reference trajectory and a planning of alternative paths. Finally, the bilateral component of the human-robot interaction is realized by feeding back to the operator a force cue informative of the global deformation acting on the desired path rather than on a local mismatch between commanded and executed position/velocity. Summarizing, the novel elements of this approach are: i) broadening the classical shared control approach by endowing the mobile robot with a higher planning autonomy, ii) allowing a human operator to act at the planning level rather than at the motion control level, iii) generating a force cue informative of the global deformation of the desired path rather than of the mismatch between direct motion commands and their execution. The proposed method has been extensively tested with human/hardware in-the-loop simulations, featuring a physically simulated quadrotor aerial vehicle and a haptic device (see Fig. 1).}, file_url = {fileadmin/user_upload/files/publications/2012/HFR-2012-Masone.pdf}, web_url = {http://hfr2012.wordpress.com/}, event_name = {5th International Workshop on Human-Friendly Robotics (HFR 2012)}, event_place = {Bruxelles, Belgium}, state = {published}, author = {Masone C{masone}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ CognettiSFO2012, title = {Two Measurement Scenarios for Anonymous Mutual Localization in Multi-UAV Systems}, year = {2012}, month = {10}, pages = {13-18}, abstract = {We present a method for reconstructing the relative poses among the components of a multi-UAV system using anonymous (i.e., without identity information) robot-to-robot measurements. We consider two cases: bearing-only and bearing+distance measurements. While bearing can be rather directly extracted from a camera image, visual reconstruction of distances is more elaborate and typically associated with a larger noise. Nevertheless, our experiments show that use of such metric information improves significantly the quality of the localization.}, file_url = {fileadmin/user_upload/files/publications/2012/2012l-CogSteFraOri-preprint.pdf}, web_url = {http://www.ifac-papersonline.net/Detailed/56943.html}, editor = {Halme, A. , J. Suomela}, event_name = {2nd IFAC Workshop on Multivehicle Systems (MVS 2012)}, event_place = {Espoo, Finland}, state = {published}, ISBN = {978-3-902823-15-1}, DOI = {10.3182/20121003-3-SF-4024.00006}, author = {Cognetti M{mcognetti}{Department Human Perception, Cognition and Action}, Stegagno P, Franchi A{antonio}{Department Human Perception, Cognition and Action} and Oriolo G} } @Inproceedings{ VenrooijPMvB2012, title = {A practical biodynamic feedthrough model for helicopters}, year = {2012}, month = {9}, pages = {1-13}, abstract = {Biodynamic feedthrough (BDFT) occurs when vehicle vibrations and accelerations feed through the pilot’s body and cause involuntary motion of limbs, resulting in involuntary control inputs. BDFT can severely reduce ride comfort, control accuracy and, above all, safety during the operation of rotorcraft. Furthermore, BDFT can cause and sustain Rotorcraft-Pilot Couplings (RPCs). Despite many studies conducted in past decades – both within and outside of the rotorcraft community – BDFT is still a poorly understood phenomenon. The complexities involved in BDFT have kept researchers and manufacturers in the rotorcraft domain from developing robust ways of dealing with its effects. A practical BDFT pilot model, describing the amount of involuntary control inputs as a function of accelerations, could pave the way to account for adversive BDFT effects. In the current paper, such a model is proposed. Its structure is based on the model proposed by Mayo [1], its accuracy and usability are improved by incorporating insights from recently obtained experimental data. An evaluation of the model performance shows that the model describes the measured data well and that it provides a considerable improvement to the original Mayo model. Furthermore, the results indicate that the neuromuscular dynamics have an important influence on the BDFT model parameters.}, file_url = {fileadmin/user_upload/files/publications/2012/ERF-2012-Venrooij-096.pdf}, web_url = {http://erf2012.nlr.nl/}, event_name = {38th European Rotorcraft Forum (ERF 2012)}, event_place = {Amsterdam, Netherlands}, state = {published}, author = {Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}, Pavel MD, Mulder M, van der Helm FCT and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ HerdtweckC2012_2, title = {Monocular Heading Estimation in Non-stationary Urban Environment}, year = {2012}, month = {9}, pages = {244-250}, abstract = {Estimating heading information reliably from visual cues only is an important goal in human navigation research as well as in application areas ranging from robotics to automotive safety. The focus of expansion (FoE) is deemed to be important for this task. Yet, dynamic and unstructured environments like urban areas still pose an algorithmic challenge. We extend a robust learning framework that operates on optical flow and has at center stage a continuous Latent Variable Model (LVM) [1]. It accounts for missing measurements, erroneous correspondences and independent outlier motion in the visual field of view. The approach bypasses classical camera calibration through learning stages, that only require monocular video footage and corresponding platform motion information. To estimate the FoE we present both a numerical method acting on inferred optical flow fields and regression mapping, e.g. Gaussian-Process regression. We also present results for mapping to velocity, yaw, and even pitch and roll. Performance is demonstrated for car data recorded in non-stationary, urban environments.}, note = {Best Conference Paper Award}, file_url = {fileadmin/user_upload/files/publications/2012/HerdtweckCurioMFI2012.pdf}, web_url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6343057}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Multisensor Fusion and Information Integration (MFI 2012)}, event_place = {Hamburg, Germany}, state = {published}, ISBN = {978-1-4673-2511-0}, DOI = {10.1109/MFI.2012.6343057}, author = {Herdtweck C{grueschaan}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ NestiMBRBP2012, title = {Roll rate thresholds and perceived realism in driving simulation}, year = {2012}, month = {9}, pages = {1-6}, abstract = {Due to limited operational space, in dynamic driving simulators it is common practice to implement motion cueing algorithms that tilt the simulator cabin to reproduce sustained accelerations. In order to avoid conflicting inertial cues, the tilt rate is kept below drivers’ perceptual thresholds, which are typically derived from the results of classical vestibular research where additional sensory cues to self-motion are removed. Here we conduct two experiments in order to assess whether higher tilt limits can be employed to expand the user’s perceptual workspace of dynamic driving simulators. In the first experiment we measure detection thresholds for roll in conditions that closely resemble typical driving. In the second experiment we measure drivers’ perceived realism in slalom driving for sub-, near- and supra-threshold roll rates. Results show that detection threshold for roll in an active driving task is remarkably higher than the limits currently used in motion cueing algorithms to drive simulators. Supra-threshold roll rates in the slalom task are also rated as more realistic. Overall, our findings suggest that higher tilt limits can be successfully implemented in motion cueing algorithms to better optimize simulator operational space.}, file_url = {fileadmin/user_upload/files/publications/2012/DSC-2012-Nest.pdf}, web_url = {http://dsc2010.ensam.eu/}, event_name = {Driving Simulation Conference Europe (DSC 2012)}, event_place = {Paris, France}, state = {published}, author = {Nesti A{ale}{Department Human Perception, Cognition and Action}, Masone C{masone}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Pretto P{pretto}{Department Human Perception, Cognition and Action}} } @Inproceedings{ BiegCFRB2012, title = {Einfluss von Ablenkung und Augenbewegungen auf Steuerungsaufgaben}, year = {2012}, month = {8}, pages = {341-344}, abstract = {In der vorliegenden Studie wurde der Einfluss visueller Ablenkung auf Steuerungsaufgaben untersucht. Die Ergebnisse deuten darauf hin, dass bereits eine kurze Verlagerung der Aufmerksamkeit und des Blicks mit einer systematischen Beeinflussung der Steuerungsaufgabe einhergeht. Im Gegenzug findet auch eine systematische Beeinflussung der Augenbewegungen durch die gleichzeitig durchgeführte Steuerungsaufgabe statt. Die Berücksichtigung solcher Interferenzen kann bei der Entwicklung von grafischen On-Board-Informationssystemen für Fahr- oder Flugzeuge von Nutzen sein.}, web_url = {http://dl.mensch-und-computer.de/handle/123456789/2907}, editor = {Reiterer, H. , O. Deussen}, publisher = {Oldenbourg}, address = {München, Germany}, booktitle = {Mensch & Computer 2012: 12. fachübergreifende Konferenz für interaktive und kooperative Medien}, event_name = {Mensch & Computer (M&C)}, event_place = {Konstanz, Germany}, state = {published}, ISBN = {978-3-486-71879-9}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Inproceedings{ OlivariNVBP2012, title = {Multi-loop Pilot Behavior Identification in Response to Simultaneous Visual and Haptic Stimuli}, year = {2012}, month = {8}, pages = {1-23}, abstract = {The goal of this paper is to better understand how the neuromuscular system of a pilot, or more generally an operator, adapts itself to di erent types of haptic aids during a pitch control task. A multi-loop pilot model, capable of describing the human behaviour during a tracking task, is presented. Three di erent identi cation techniques were investigated in order to simultaneously identify neuromuscular admittance and the visual response of a human pilot. In one of them, the various frequency response functions that build up the pilot model are identi ed using multi-inputs linear time-invariant models in ARX form. A second method makes use of cross-spectral densities and diagram block algebra to obtain the desired frequency response estimates. The identi cation techniques were validated using Monte Carlo simulations of a closed-loop control task. Both techniques were compared with the results of another identi cation method well known in literature and based on cross-spectral density estimates. All those methods were applied in an experimental setup in which pilots performed a pitch control task with di erent haptic aids. Two di erent haptic aids for tracking task are presented, a Direct Haptic Aid and an Indirect Haptic Aid. The two haptic aids were compared with a baseline condition in which no haptic force was used. The data obtained with the proposed method provide insight in how the pilot adapts his control behavior in relation to di erent haptic feedback schemes. From the experimental results it can be concluded that humans adapt their neuromuscular admittance in relation with di erent haptic aids. Furthermore, the two new identi cation techniques seemed to give more reliable admittance estimates.}, file_url = {fileadmin/user_upload/files/publications/2012/Olivari2012.pdf}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2012-4795}, event_name = {AIAA Modeling and Simulation Technologies Conference 2012}, event_place = {Minneapolis, MN, USA}, state = {published}, ISBN = {978-1-62410-183-0}, DOI = {10.2514/6.2012-4795}, author = {Olivari M, Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Pollini L} } @Inproceedings{ ZelazoFABR2012, title = {Rigidity Maintenance Control for Multi-Robot Systems}, year = {2012}, month = {7}, pages = {1-8}, abstract = {Rigidity of formations in multi-robot systems is important for formation control, localization, and sensor fusion. This work proposes a rigidity maintenance gradient controller for a multi-agent robot team. To develop such a controller, we first provide an alternative characterization of the rigidity matrix and use that to introduce the novel concept of the rigidity eigenvalue. We provide a necessary and sufficient condition relating the positivity of the rigidity eigenvalue to the rigidity of the formation. The rigidity maintenance controller is based on the gradient of the rigidity eigenvalue with respect to each robot position. This gradient has a naturally distributed structure, and is thus amenable to a distributed implementation. Additional requirements such as obstacle and inter-agent collision avoidance, as well as typical constraints such as limited sensing/communication ranges and line-of-sight occlusions, are also explicitly considered. Finally, we present a simulation with a group of seven quadrotor UAVs to demonstrate and validate the theoretical results.}, file_url = {fileadmin/user_upload/files/publications/2012/2012g-ZelFraAlgBueRob-preprint.pdf}, web_url = {http://www.roboticsproceedings.org/rss08/index.html}, booktitle = {Robotics: Science and Systems VIII}, event_name = {2012 Robotics: Science and Systems Conference}, event_place = {Sydney, Australia}, state = {published}, ISBN = {9780262519687}, author = {Zelazo D, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Allg\"ower P, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ EngelC2012, title = {Detectability prediction in dynamic scenes for enhanced environment perception}, year = {2012}, month = {6}, pages = {178-183}, abstract = {A driver assistance system realizes that the driver is distracted and that a potentially hazardous situation is emerging. Where should it guide the attention of the driver? Optimally to the spot that allows the driver to make the best decision. Pedestrian detectability has been proposed recently as a measure of the probability that a driver perceives pedestrians in an image [9]. Leveraging this information allows a driver assistance system to direct the attention of the driver to the spot that maximizes the probability that all pedestrians are seen. In this paper we extend this concept to dynamic scenes. We use an annotated video dataset recorded from a moving car in an urban environment and acquire the detectabilities of pedestrians via a psychophysical experiment. Based on these measured detectabilites we train a machine learning algorithm to predict detectabilities from a set of image features. We then exploit this mapping to predict the optimal focus of attention in a second experiment, thus demonstrating the usefulness of our method in a dynamic driver assistance context.}, file_url = {fileadmin/user_upload/files/publications/2012/IV2012-Engel.pdf}, web_url = {http://www.robesafe.es/iv2012/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE Intelligent Vehicles Symposium (IV 2012)}, event_place = {Alcalá de Henares, Spain}, state = {published}, DOI = {10.1109/IVS.2012.6232267}, author = {Engel D{engel}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ HerdtweckC2012, title = {Experts of probabilistic flow subspaces for robust monocular odometry in urban areas}, year = {2012}, month = {6}, pages = {661-667}, abstract = {Visual odometry has been promoted as a fundamental component for intelligent vehicles. Relying solely on monocular image cues would be desirable. Nevertheless, this is a challenge especially in dynamically varying urban areas due to scale ambiguities, independent motions, and measurement noise. We propose to use probabilistic learning with auxiliar depth cues. Specifically, we developed an expert model that specializes monocular egomotion estimation units on typical scene structures, i.e. statistical variations of scene depth layouts. The framework adaptively selects the best fitting expert. For on-line estimation of egomotion, we adopted a probabilistic subspace flow estimation method. Learning in our framework consists of two components: 1) Partitioning of datasets of video and ground truth odometry data based on unsupervised clustering of dense stereo depth profiles and 2) training a cascade of subspace flow expert models. A probabilistic quality measure from the estimates of the experts provides a selection rule overall leading to improvements of egomotion estimation for long test sequences.}, file_url = {fileadmin/user_upload/files/publications/2012/IV-2012-Herdtweck-Curio.pdf}, web_url = {http://www.robesafe.es/iv2012/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE Intelligent Vehicles Symposium (IV 2012)}, event_place = {Alcalá de Henares, Spain}, state = {published}, DOI = {10.1109/IVS.2012.6232238}, author = {Herdtweck C{grueschaan}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ CognettiSFOB2012, title = {3-D Mutual Localization with Anonymous Bearing Measurements}, year = {2012}, month = {5}, pages = {791-798}, abstract = {We present a decentralized algorithm for estimating mutual 3-D poses in a group of mobile robots, such as a team of UAVs. Our algorithm uses bearing measurements reconstructed, e.g., by a visual sensor, and inertial measurements coming from the robot IMU. Since identification of a specific robot in a group would require visual tagging and may be cumbersome in practice, we simply assume that the bearing measurements are anonymous. The proposed localization method is a non-trivial extension of our previous algorithm for the 2-D case [1], and exhibits similar performance and robustness. An experimental validation of the algorithm has been performed using quadrotor UAVs.}, file_url = {fileadmin/user_upload/files/publications/2012/2012c-CogSteFraOriBue.pdf}, web_url = {http://www.icra2012.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2012)}, event_place = {St. Paul, MN, USA}, state = {published}, DOI = {10.1109/ICRA.2012.6225288}, author = {Cognetti M{mcognetti}{Department Human Perception, Cognition and Action}, Stegagno P, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Oriolo G and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ BrowatzkiTMBW2012, title = {Active Object Recognition on a Humanoid Robot}, year = {2012}, month = {5}, pages = {2021-2028}, abstract = {Interaction with its environment is a key requisite for a humanoid robot. Especially the ability to recognize and manipulate unknown objects is crucial to successfully work in natural environments. Visual object recognition, however, still remains a challenging problem, as three-dimensional objects often give rise to ambiguous, two-dimensional views. Here, we propose a perception-driven, multisensory exploration and recognition scheme to actively resolve ambiguities that emerge at certain viewpoints. We define an efficient method to acquire two-dimensional views in an object-centered task space and sample characteristic views on a view sphere. Information is accumulated during the recognition process and used to select actions expected to be most beneficial in discriminating similar objects. Besides visual information we take into account proprioceptive information to create more reliable hypotheses. Simulation and real-world results clearly demonstrate the efficiency of active, multisensory exploration over passive, visiononly recognition methods.}, file_url = {fileadmin/user_upload/files/publications/2012/ICRA-2012-Browatzki.pdf}, web_url = {http://www.icra2012.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2012)}, event_place = {St. Paul, MN, USA}, state = {published}, DOI = {10.1109/ICRA.2012.6225218}, author = {Browatzki B{browatbn}{Department Human Perception, Cognition and Action}, Tikhanoff V, Metta G, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Inproceedings{ SecchiFBP2012, title = {Bilateral teleoperation of a group of UAVs with communication delays and switching topology}, year = {2012}, month = {5}, pages = {4307-4314}, abstract = {In this paper, we present a passivity-based decentralized approach for bilaterally teleoperating a group of UAVs composing the slave side of the teleoperation system. In particular, we explicitly consider the presence of time delays, both among the master and slave, and within UAVs composing the group. Our focus is on analyzing suitable (passive) strategies that allow a stable teloperation of the group despite presence of delays, while still ensuring high flexibility to the group topology (e.g., possibility to autonomously split or join during the motion). The performance and soundness of the approach is validated by means of human/hardware-in-the-loop simulations (HHIL).}, file_url = {fileadmin/user_upload/files/publications/2012/ICRA-2012-Secchi.pdf}, web_url = {http://www.icra2012.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2012)}, event_place = {St. Paul, MN, USA}, state = {published}, DOI = {10.1109/ICRA.2012.6225304}, author = {Secchi C, Franchi A{antonio}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ VenrooijYPQJM2011, title = {Measuring biodynamic feedthrough in helicopters}, year = {2012}, month = {5}, pages = {958-967}, abstract = {Biodynamic feedthrough (BDFT) refers to a phenomenon where vehicle accelerations cause involuntary pilot limb motions which, when coupled to a control device, can result in unintentional control inputs. It is known that BDFT occurs in helicopters, amongst many other vehicles. The goal of the current study is to analyze the pilot’s response to helicopter motion and experimentally determine the level of BDFT occurring in helicopters. In this study, BDFT was measured for the collective and the cyclic control devices, in roll, pitch, and vertical direction, for three different control tasks, a position task (PT) or ’stiff task’, a force task (FT) or ’compliant task’, and a relax task (RT). The study focuses on the influence of the pilot’s neuromuscular dynamics on the level of BDFT. Two major conclusions can be drawn from the experimental results: 1) BDFT in helicopters is task dependent 2) the highest level of BDFT is measured in lateral direction, followed by longitudinal and finally vertical direction.}, file_url = {fileadmin/user_upload/files/publications/2011/ERF-2011-Venrooij.pdf}, web_url = {http://www.erf2011.org/}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {37th European Rotorcraft Forum (ERF 2011)}, event_place = {Vergiate, Gallarate, Italy}, state = {published}, ISBN = {978-1-61839-626-6}, author = {Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}, Yilmaz D, Pavel MD, Quaranta G, Jump M and Mulder M} } @Inproceedings{ RyllBR2012_2, title = {Modeling and Control of a Quadrotor UAV with Tilting Propellers}, year = {2012}, month = {5}, pages = {4606-4613}, abstract = {Standard quadrotor UAVs possess a limited mobility because of their inherent underactuation, i.e., availability of 4 independent control inputs (the 4 propeller spinning velocities) vs. the 6 dofs parameterizing the quadrotor position/ orientation in space. As a consequence, the quadrotor pose cannot track an arbitrary trajectory over time (e.g., it can hover on the spot only when horizontal). In this paper, we propose a novel actuation concept in which the quadrotor propellers are allowed to tilt about their axes w.r.t. the main quadrotor body. This introduces an additional set of 4 control inputs which provides full actuation to the quadrotor position/orientation. After deriving the dynamical model of the proposed quadrotor, we formally discuss its controllability properties and propose a nonlinear trajectory tracking controller based on dynamic feedback linearization techniques. The soundness of our approach is validated by means of simulation results.}, web_url = {http://www.icra2012.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2012)}, event_place = {St. Paul, MN, USA}, state = {published}, DOI = {10.1109/ICRA.2012.6225129}, author = {Ryll M{maryll}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ JumpPPWFFZSSBDSMHNB2011, title = {MyCopter: Enabling Technologies for Personal Air Transport Systems}, year = {2012}, month = {5}, pages = {336-347}, abstract = {This paper describes the European Commission (EC) Framework 7 funded project myCopter (2011-2014). The project is still at an early stage so the paper starts with the current transportation issues faced by developed countries and describes a means to solve them through the use of personal aerial transportation. The concept of personal air vehicles (PAV) is briefly reviewed and how this project intends to tackle the problem from a different perspective described. It is argued that the key reason that many PAV concepts have failed is because the operational infrastructure and socio-economic issues have not been properly addressed; rather, the start point has been the design of the vehicle itself. Some of the key aspects that would make a personal aerial transport system (PATS) viable include the required infrastructure and associated technologies, the skill levels and machine interfaces needed by the occupant or pilot and the views of society as a whole on the acceptability of such a proposition. The myCopter project will use these areas to explore the viability of PAVs within a PATS. The paper reports upon the early progress made within the project. An initial reference set of PAV requirements has been collated. A non-physical flight simulation model capable of providing a wide range of handling qualities characteristics has been developed and its function has undergone limited verification. Results from this exercise show that the model behaves as intended and that it can deliver a predictable range of vehicle dynamics. The future direction of the themes of work described within the paper are then described.}, file_url = {fileadmin/user_upload/files/publications/2011/ERF2011_122.pdf}, web_url = {http://www.erf2011.org/}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {37th European Rotorcraft Forum (ERF 2011)}, event_place = {Vergiate, Gallarate, Italy}, state = {published}, ISBN = {978-1-61839-626-6}, author = {Jump M, Perfect P, Padfield GD, White MD, Floreano D, Fua P, Zufferey J-C, Schill F, Siegwart R, Bouabdallah S, Decker M, Schippl J, Mayer S, H\"ofinger M, Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ GrabeBR2012_2, title = {On-board velocity estimation and closed-loop control of a quadrotor UAV based on optical flow}, year = {2012}, month = {5}, pages = {491-497}, abstract = {Robot vision became a field of increasing importance in micro aerial vehicle robotics with the availability of small and light hardware. While most approaches rely on external ground stations because of the need of high computational power, we will present a full autonomous setup using only on-board hardware. Our work is based on the continuous homography constraint to recover ego-motion from optical flow. Thus we are able to provide an efficient fall back routine for any kind of UAV (Unmanned Aerial Vehicles) since we rely solely on a monocular camera and on on-board computation. In particular, we devised two variants of the classical continuous 4-point algorithm and provided an extensive experimental evaluation against a known ground truth. The results show that our approach is able to recover the ego-motion of a flying UAV in realistic conditions and by only relying on the limited on-board computational power. Furthermore, we exploited the velocity estimation for closing the loop and controlling the motion of the UAV online.}, file_url = {fileadmin/user_upload/files/publications/2012/ICRA2012-Grabe.pdf}, web_url = {http://www.icra2012.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2012)}, event_place = {St. Paul, MN, USA}, state = {published}, ISBN = {978-1-4673-1403-9}, DOI = {10.1109/ICRA.2012.6225328}, author = {Grabe V{vgrabe}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ QuarantaMV2012, title = {Robust Stability Analysis: a Tool to Assess the Impact of Biodynamic Feedthrough on Rotorcraft}, year = {2012}, month = {5}, pages = {1306-1315}, abstract = {Biodynamic feedthrough (BDFT) may significantly affect the closed-loop behavior of rotorcraft, reducing the stability and increasing the proneness to Rotorcraft-Pilot Couplings (RPC). Leveraging robust stability analysis, the inherently uncertain pilot BDFT can be treated as the uncertain portion of a feedback system, allowing analytical, numerical or graphical determination of proneness to RPC by comparing robust stability margins of helicopter models with BDFT data. The application of the proposed approach to collective bounce is exemplified using simple analytical helicopter and pilot BDFT models, and applied to detailed helicopter models and BDFT measurement data.}, file_url = {fileadmin/user_upload/files/publications/2012/AHS-2012-Quaranta.pdf}, web_url = {http://www.aero.polimi.it/mbdyn/documentation/research/rpc/index.html}, web_url2 = {http://toc.proceedings.com/15008webtoc.pdf}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {68th American Helicopter Society International Annual Forum (AHS 2012)}, event_place = {Fort Worth, TX, USA}, state = {published}, ISBN = {78-1-62276-051-0}, author = {Quaranta G, Masarati P and Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}} } @Inproceedings{ HongBS2012, title = {Experimental Design for the Evaluation of a Multi-Modal Feedback in Multi-Robot Teleoperation}, year = {2012}, month = {4}, pages = {-}, web_url = {http://conference.icros.org/}, publisher = {Institute of Control, Robotics and Systems}, address = {Bucheon, South Korea}, event_name = {27th ICROS Annual Conference (ICROS 2012)}, state = {published}, author = {Hong A{ahong}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Son HI{chakurt}{Department Human Perception, Cognition and Action}} } @Inproceedings{ AlexandrovaRBTKBM2012, title = {Enhancing Medical Communication Training Using Motion Capture, Perspective Taking and Virtual Reality}, year = {2012}, month = {2}, pages = {16-22}, abstract = {The aim of this work is to increase the effectiveness of real world medical training simulations by helping trainees gain a better understanding of the importance of communication and teamwork. Therefore we develop an online application which can be used together with real world simulations to improve training. To produce the online application we reconstructed two real world scenarios (one with students and one with practitioners) in an immersive virtual environment. Our application enables the trainees to view the scenario from different perspectives or to freely explore the environment. We aim to integrate it into the medical student curriculum at the University of Tübingen.}, web_url = {http://www.nextmed.com/index.html}, editor = {Westwood, J.D. , S.W. Westwood, L. Felländer-Tsai, R.S. Haluck, R.A. Robb, S. Senger, K.G. Vosburgh}, publisher = {IOS Press}, address = {Amsterdam, Netherlands}, booktitle = {Medicine Meets Virtual Reality 19: NextMed}, event_name = {19th Medicine Meets Virtual Reality Conference (MMVR 2012)}, event_place = {Newport Beach, CA, USA}, state = {published}, ISBN = {978-1-61499-021-5}, DOI = {10.3233/978-1-61499-022-2-16}, author = {Alexandrova IV{ivelina}{Department Human Perception, Cognition and Action}, Rall M, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, Tullius G, Kloos C, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Inbook{ MohlerdB2012, title = {Multisensory contributions to spatial perception}, year = {2012}, month = {10}, pages = {81-97}, editor = {Waller, D. , L. Nadel}, publisher = {American Psychological Association}, address = {Washington, DC, USA}, booktitle = {Handbook of Spatial Cognition}, state = {published}, ISBN = {978-1-433-81204-0}, author = {Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, Di Luca M{max}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inbook{ CamposB2011, title = {Multimodal Integration during Self-Motion in Virtual Reality}, year = {2012}, month = {1}, pages = {603-628}, abstract = {This chapter begins by a brief description of some of the different types of simulation tools and techniques that are being used to study self-motion perception, along with some of the advantages and disadvantages of the different interfaces. Subsequently, some of the current empirical work investigating multisensory self-motion perception using these technologies will be summarized, focusing mainly on visual, proprioceptive, and vestibular influences during full-body self-motion through space. Finally, the implications of this research for several applied areas will be briefly described.}, file_url = {fileadmin/user_upload/files/publications/2011/Campos-Buelthoff-MultisensorySelfMotion.pdf}, web_url = {http://www.crcnetbase.com/doi/abs/10.1201/b11092-38}, editor = {Murray, M. M. , M. T. Wallace}, publisher = {CRC Press}, address = {Boca Raton, FL, USA}, series = {Frontiers in Neuroscience}, booktitle = {The neural bases of multisensory processes}, state = {published}, ISBN = {978-1-4398121-7-4}, DOI = {10.1201/b11092-38}, author = {Campos JL{camposjl}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Techreport{ LeeB2012, title = {Helilab User Manual: Human Behavior and Flight Data Acquisition and Analysis}, year = {2012}, month = {5}, number = {196}, abstract = {We, here, introduce a flight simulator dedicated to collect both human behavior and flight data with high fidelity. This paper illustrates the current settings of the flight simulator, key issues in using the simulator, and the standard procedure of data acquisition and analysis.}, file_url = {fileadmin/user_upload/files/publications/2012/MPIK-TR-196a.pdf}, state = {published}, author = {Lee J-J{jlee}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ EsinsSKWB2012_2, title = {Comparing the other race effect and congenital prosopagnosia using a three-experiment test battery}, year = {2012}, month = {11}, volume = {13}, pages = {38}, abstract = {Congenital prosopagnosia, an innate impairment in recognizing faces, as well as the otherrace-effect, the disadvantage in recognizing faces of foreign races, both influence face recognition abilities. Here we compared both phenomena by testing three groups: German congenital prosopagnosics (cPs), unimpaired German and unimpaired South Korean participants (n=23 per group), on three tests with Caucasian faces. First we ran the Cambridge Face Memory Test (Duchaine & Nakayama, 2006 Neuropsychologia 44 576-585). Participants had to recognize Caucasian target faces in a 3AFC task. German controls performed better than Koreans (p=0.009) who performed better than prosopagnosics (p=0.0001). Variation of the individual performances was larger for cPs than for Koreans (p = 0.028). In the second experiment, participants rated the similarity of Caucasian faces (in-house 3D face-database) which differed parametrically in features or second order relations (configuration). We found differences between sensitivities to change type (featural or configural, p=0) and between groups (p=0.005) and an interaction between both factors (p = 0.019). During the third experiment, participants had to learn exemplars of artificial objects (greebles), natural objects (shells), and faces and recognize them among distractors. The results showed an interaction (p = 0.005) between stimulus type and participant group: cPs where better for non-face stimuli and worse for face stimuli than the other groups. Our results suggest that congenital prosopagnosia and the other-race-effect affect face perception in different ways. The broad range in performance for the cPs directs the focus of our future research towards looking for different forms of congenital prosopagnosia.}, web_url = {http://www.neuroschool-tuebingen-nena.de/}, event_name = {13th Conference of the Junior Neuroscientists of Tübingen (NeNA 2012)}, event_place = {Schramberg, Germany}, state = {published}, author = {Esins J{esins}{Department Human Perception, Cognition and Action}, Schultz J{johannes}{Department Human Perception, Cognition and Action}, Kim BR, Wallraven C{walli}{Department Human Perception, Cognition and Action} and B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Poster{ NestiBPB2012, title = {Human sensitivity to different motion intensities}, year = {2012}, month = {11}, volume = {13}, pages = {27}, abstract = {Sensory information processes leading to human self-motion perception have been modelled in the past in terms of visual and inertial stimulations and their interactions. The models, validated through many psychophysical experiments, rely on the assumption that our sensitivity to supra-threshold self-motion is not affected by motion intensity. In other words, the relationship between motion stimulus intensity and human sensitivity to motion is assumed to be linear. However, recent studies have shown that this relationship is non-linear, in particular at higher motion intensity. Therefore, the implementation of nonlinearities in the computational models of human motion perception would increase their accuracy over a wider range of motion stimulus intensity. Here we test human sensitivity for sinusoidal yaw rotation in darkness at frequencies of 0.5 Hz and 1 Hz and velocity amplitudes ranging between 0 and 90 deg/s. In a two interval force choice experimental paradigm, subjects undergo two consecutive rotations in the same direction for each trial. One of these movements is repeated unchanged in every trial, while the other systematically varies in amplitude. Subjects are asked to report after each trial which one of the two movements was stronger. An adaptive staircase adjusts the motion for every trial to identify the smallest detectable change in stimulus intensity (differential threshold). Results show a power law relationship between differential thresholds and stimulus intensity, meaning that sensitivity decreases as motion becomes stronger. No frequency effect is observed. These findings are of particular interest for the field of vehicle motion simulation, where knowledge about self-motion perception is widely exploited to overcome the physical limitations of motion-based simulators. Furthermore, the identification of perceptual nonlinearities in multisensory stimulation will guide future work into understanding the neural mechanisms responsible for self-motion perception.}, web_url = {http://www.neuroschool-tuebingen-nena.de/}, event_name = {13th Conference of the Junior Neuroscientists of Tübingen (NeNA 2012)}, event_place = {Schramberg, Germany}, state = {published}, author = {Nesti A{ale}{Department Human Perception, Cognition and Action}, Beykirch K{kab}{Department Human Perception, Cognition and Action}, Pretto P{pretto}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ RoheN2012_2, title = {Neural audiovisual representations of space in sensory and higher multisensory cortices}, year = {2012}, month = {10}, volume = {42}, number = {463.12}, abstract = {Previous research has demonstrated that human observers locate audiovisual signals in space by averaging auditory (A) and visual (V) spatial signals according to their relative sensory reliabilities (=inverse of variance) (Ernst & Banks, 2002; Alais & Burr, 2004). This form of audiovisual integration is optimal in that it provides the most reliable percept.Yet, the neural systems mediating integration of spatial inputs remain unclear. Multisensory integration of spatial signals has previously been related to higher order association areas such as intraparietal sulcus (IPS) as well as the planum temporale (PT; Bonath et al., 2007). In the current fMRI study, we investigated whether and how early sensory (auditory cortex (A1), PT; visual regions V1-V3) and higher association (IPS) areas represent A and V spatial information. Subjects were presented with synchronous audiovisual signals, at spatially congruent or discrepant locations along the azimuth and at two levels of sensory reliability. Hence, the experimental design factorially manipulated: (1) V location, (2) A location, (3) V reliability. Subjects’ task was to localize the A signal. At the behavioral level, the perceived location of the A input was shifted towards the location of the V input depending on the relative A and V reliabilities. Likewise, at the neural level, the spatial location decoded with linear support vector machines from fMRI signals in brain areas along the A and V processing hierarchies was determined by the relative sensory reliabilities. The spatial location decoded from A1/PT was determined primarily by A spatial information with a stronger influence from V spatial information when the V reliability was high. Conversely, the spatial location decoded from visual areas (V1, V2, V3) and IPS was determined primarily by V spatial information with a stronger A influence when the V information was less reliable. In conclusion, our results suggest that the brain represents audiovisual spatial location in qualitative agreement with reliability-weighted multisensory integration at multiple levels of the cortical processing hierarchy.}, web_url = {http://www.sfn.org/am2012/}, event_name = {42nd Annual Meeting of the Society for Neuroscience (Neuroscience 2012)}, event_place = {New Orleans, LA, USA}, state = {published}, author = {Rohe T{trohe}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Poster{ Genewein2012, title = {A Sensorimotor Paradigm for Bayesian Model Selection}, year = {2012}, month = {9}, web_url = {http://www.uni-tuebingen.de/einrichtungen/zentrale-einrichtungen/forum-scientiarum/studium/akademien/archiv/sa-2012-2-decisions.html}, event_name = {Tübingen International Summerschool 2012 (TISS 2012)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Genewein T{tgenewein}{Research Group Sensorimotor Learning and Decision-Making}} } @Poster{ BiegBBC2012_2, title = {Asymmetries in saccadic latencies during interrupted ocular pursuit}, journal = {Perception}, year = {2012}, month = {9}, volume = {41}, number = {ECVP Abstract Supplement}, pages = {137}, abstract = {Smooth pursuit eye movements can be interrupted and resumed at a later stage, eg, when a concurrent task requires visual sampling from elsewhere. Here we address whether and how interruptive saccades are affected by pursuit movements. Our participants pursued an object which moved horizontally in a sinusoidal pattern (frequency: 0.25 Hz, amplitude: 4 deg. visual angle). During this, discrimination targets appeared at 10 deg. eccentricity, to the left or right of the center. They were timed so that they appeared for 1 second while the pursuit object moved either toward or away from the discrimination target's position. Saccade reaction times were earlier when the discrimination targets appeared in a position that the tracking object was moving towards. Interestingly, saccade RTs back to the pursuit object were shorter when the object moved away from the discrimination target. We conclude that interruptions of pursuit movements lead to asymmetries in saccade generation. These asymmetries could have been caused by biases in attention along the predicted pursuit path.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v120443}, event_name = {35th European Conference on Visual Perception}, event_place = {Alghero, Italy}, state = {published}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Poster{ EsinsBKS2012, title = {Can a test battery reveal subgroups in congenital prosopagnosia?}, journal = {Perception}, year = {2012}, month = {9}, volume = {41}, number = {ECVP Abstract Supplement}, pages = {113}, abstract = {Congenital prosopagnosia, the innate impairment in recognizing faces exhibits diverse deficits. Due to this heterogeneity the possible existence of subgroups of the impairment was suggested (eg Kress and Daum, 2003 Behavioural Neurology14109-21). We examined 23 congenital prosopagnosics (cPAs) identified via a screening questionnaire (as used in Stollhoff, Jost, Elze, and Kennerknecht, 2011 PLoS ONE6e15702) and 23 age-, gender and educationally matched controls with a battery consisting of nine different tests. These included well known tests like the Cambridge Face Memory Test (CFMT, Duchaine and Nakayama, 2006 Neuropsychologia44576-85), a Famous Face Test (FFT), and new, own tests about object and face recognition. As expected, cPAs had lower CFMT and FFT scores than the controls. Analyses of the performance patterns across the nine tests suggest the existence of subgroups within both cPAs and controls. These groups could not be revealed only based on the CFMT and FFT scores, indicating the necessity of tests addressing different, specific aspects of object and face perception for the identification of subgroups. Current work focuses on characterizing the subgroups and identifying the most useful tests.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v120524}, event_name = {35th European Conference on Visual Perception}, event_place = {Alghero, Italy}, state = {published}, author = {Esins J{esins}{Department Human Perception, Cognition and Action}, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}, Kennerknecht I and Schultz J{johannes}{Department Human Perception, Cognition and Action}} } @Poster{ EndresANG2012_2, title = {Explicit coding in the brain: data-driven semantic analysis of human fMRI BOLD responses with Formal Concept Analysis}, journal = {Frontiers in Computational Neuroscience}, year = {2012}, month = {9}, volume = {Conference Abstract: Bernstein Conference 2012}, pages = {166}, abstract = {Understanding how semantic information is represented in the brain has been an important research focus of neuroscience in the past few years. We showed previously (Endres et al 2010) that Formal Concept Analysis (FCA, (Ganter and Wille 1999)) can reveal interpretable semantic information (e.g. specialization hierarchies, or feature-based representation) from electrophysiological data. Unlike other analysis methods (e.g. hierarchical clustering), FCA does not impose inappropriate structure on the data. FCA is a mathematical formalism compatible with the explicit coding hypothesis (Foldiak, 2009) Here, we investigate whether similar findings can be obtained from fMRI BOLD responses recorded from human subjects. While the BOLD response provides only an indirect measure of neural activity on a much coarser spatio-temporal scale than electrophysiological recordings, it has the advantage that it can be recorded from humans, which can be questioned about their perceptions during the experiment, thereby obviating the need of interpreting animal behavioural responses. Furthermore, the BOLD signal can be recorded from the whole brain simultaneously. In our experiment, a single human subject was scanned while viewing 72 grayscale pictures of animate and inanimate objects in a target detection task (Siemens Trio 3T scanner, GE-EPI, TE=40ms, 38 axial slices, TR=3.08s, 48 sessions, amounting to a total of 10,176 volume images). These pictures comprise the formal objects for FCA. We computed formal attributes by learning a hierarchical Bayesian classifier, which maps BOLD responses onto binary features, and these features onto object labels. The connectivity matrix between the binary features and the object labels can then serve as the formal context. In line with previous reports, FCA revealed a clear dissociation between animate and inanimate objects in a high-level visual area (inferior temporal cortex, IT), with the inanimate category including plants. The inanimate category was subdivided into plants and non-plants when we increased the number of attributes extracted from the fMRI responses. FCA also highlighted organizational differences between the IT and the primary visual cortex, V1. We show that subjective familiarity and similarity ratings are strongly correlated with the attribute structure computed from the fMRI signal.}, web_url = {http://www.frontiersin.org/10.3389/conf.fncom.2012.55.00056/event_abstract}, event_name = {Bernstein Conference 2012}, event_place = {München, Germany}, state = {published}, DOI = {10.3389/conf.fncom.2012.55.00056}, author = {Endres D, Adam R{ruthi}{Research Group Cognitive Neuroimaging}, Noppeney U{unoppe}{Research Group Cognitive Neuroimaging} and Giese MA{giese}} } @Poster{ ChuangNB2012, title = {Eye-movement planning during flight maneuvers}, journal = {Perception}, year = {2012}, month = {9}, volume = {41}, number = {ECVP Abstract Supplement}, pages = {99}, abstract = {How are eye-movements planned to access relevant visual information during flight control? From the cockpit perspective, there are two classes of visual information that are relevant for flight control. First, the changing visuals of the external world provide direct perceptual feedback on how the pilot's command of the control stick is affecting the aircraft's current position, orientation and velocity. Second, flight instruments provide abstracted and specific values—on factors such as the aircraft's compass bearing and vertical speed—that have to be continuously monitored, in order for the global objective of certain maneuvers (eg, turns) to be achieved. Trained pilots have to coordinate their eye-movements across this structured visual workspace (ie, outside view and instruments) to access timely and task-relevant information. The current work focuses on providing descriptions of these planned eye-movements. Eye-movements were recorded of pilots in a high-fidelity flight simulator (100° field-of-view) whilst they performed specific flight maneuvers. Fixation durations and transitions between the individual instruments and aspects of the external environment are represented as network graphs. This allowed us to formally describe the sources of information that were relied on across the different tasks and to compare actual performance to expert predictions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v120634}, event_name = {35th European Conference on Visual Perception}, event_place = {Alghero, Italy}, state = {published}, author = {Chuang L{chuang}{Department Human Perception, Cognition and Action}, Nieuwenhuizen F{fmnieuwenhuizen}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ RoheN2012_3, title = {Intraparietal sulcus represents audiovisual space}, journal = {Frontiers in Computational Neuroscience}, year = {2012}, month = {9}, volume = {Conference Abstract: Bernstein Conference 2012}, pages = {192-193}, abstract = {Previous research has demonstrated that human observers locate audiovisual (AV) signals in space by averaging auditory (A) and visual (V) spatial signals according to their relative sensory reliabilities (=inverse of variance) (Ernst & Banks, 2002; Alais & Burr, 2004). This form of AV integration is optimal in that it provides the most reliable percept. Yet, the neural systems mediating integration of spatial inputs remain unclear. Multisensory integration of spatial signals has previously been related to higher order association areas such as intraparietal sulcus (IPS) as well as early sensory areas like the planum temporale (Bonath et al., 2007). In the current fMRI study, we investigated whether and how early visual (V1-V3) and higher association (IPS) areas represent A and V spatial information given their retinotopic organization. One subject was presented with synchronous audiovisual signals, at spatially congruent or discrepant locations along the azimuth and at two levels of sensory reliability. Hence, the experimental design factorially manipulated: (1) V location, (2) A location, (3) V reliability. The subject’s task was to localize the A signal. Retinotopic maps in visual areas and IPS were measured with standard wedge and ring checkerboard stimuli. At the behavioral level, the perceived location of the A input was shifted towards the location of the V input depending on the relative A and V reliabilities. At the neural level, the cue locations represented in retinotopic maps were decoded by computing a population vector estimate (Pouget et al., 2000) from the voxels’ BOLD responses to the AV cues given the voxels’ preferred visual field coordinate. In early visual areas (V1-V3), the decoded cue locations were determined by the V spatial signal but were independent from the A spatial signal. In IPS, the decoded cue locations were determined by the V and the A spatial signals if relative V reliability was low. In conclusion, our results suggest that the brain represents AV spatial location in IPS in qualitative agreement with reliability-weighted multisensory integration.}, web_url = {http://www.frontiersin.org/10.3389/conf.fncom.2012.55.00054/event_abstract}, event_name = {Bernstein Conference 2012}, event_place = {München, Germany}, state = {published}, DOI = {10.3389/conf.fncom.2012.55.00054}, author = {Rohe T{trohe}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Poster{ KaulardSWBd2012, title = {Inverting natural facial expressions puzzles you}, journal = {Perception}, year = {2012}, month = {9}, volume = {41}, number = {ECVP Abstract Supplement}, pages = {103}, abstract = {The face inversion effect has often been demonstrated in face identification tasks. Less is known about whether processes underlying face expression recognition are also sensitive to face inversion. Face expression recognition is usually investigated using pictures of six emotional expressions. In everyday life, humans are however exposed to a much larger set of facial expressions, which are dynamic. Here, we examine the effect of face inversion on expression recognition for a variety of facial expressions displayed statically and dynamically. We measured participants'recognition accuracy for 12 expressions using a 13 alternative-forced-choice task. We varied the dynamics (videos versus pictures) and the orientation (upright versus inverted) of the presentation of the expressions in a completely crossed design. Accuracy was significantly higher when expressions were presented as videos (62%) than as pictures (47%). Similarly, recognition accuracy was significantly higher for upright (84%) compared to inverted (64%) expressions. Moreover, the effect of orientation changed significantly with expression type. No other effects were significant. This is the first study to report that face inversion affects the recognition of natural facial expressions. Because face inversion effects are interpreted as a sign of configural processing, our results suggest configural processing for a majority of facial expressions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v120193}, event_name = {35th European Conference on Visual Perception}, event_place = {Alghero, Italy}, state = {published}, author = {Kaulard K{kascot}{Department Human Perception, Cognition and Action}, Schultz J{johannes}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}} } @Poster{ ChuangNB2012_2, title = {Investigating Gaze Behavior of Novice Pilots during Basic Flight Maneuvers}, year = {2012}, month = {9}, web_url = {http://research.fit.edu/hci-aero/hci-aero2012/Poster_Sessions.html}, event_name = {International Conference on Human-Computer Interaction in Aerospace (HCI-Aero 2012)}, event_place = {Bruxelles, Belgium}, state = {published}, author = {Chuang LL{chuang}{Department Human Perception, Cognition and Action}, Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ LiFLK2012, title = {Multi-Stable Visual Motion Perception}, journal = {Frontiers in Computational Neuroscience}, year = {2012}, month = {9}, volume = {Conference Abstract: Bernstein Conference 2012}, pages = {190}, abstract = {Perceptual multi-stability is established when the brain fails to reach a single interpretation of the input from the external world. This issue intrigued scientific minds for more than two hundred years. This phenomenon has been found in vision (Leopold & Logothetis, 1999), audition (Repp, 2007), olfaction (Zhou & Chen, 2009) and speech (Warren & Gregory, 1958). Crucial features are similar within and across modalities (Schwarts et al., 2012). In the visual modality, a number of ambiguous visual patterns have been described such as the Necker cube, motion plaids, and binocular rivalry. Multi-stable stimuli can provide unique insights into visual processing, as changes in perception are decoupled from changes in the stimulus. Understanding of how multi-stable perception occurs might help one to understand visual perception in general. A key question in multi-stable perception is what the brain processes are responsible in the identification and alternation of the percepts. Some investigators suggest that both top-down and bottom-up processes are involved (García Pérez, 1989) but others argue that multi-stable perception does not need high-level processing but happens automatically as low-level competition between the stimulus features (Akman et al., 2009; Wilson et al, 2000). Furthermore, it is well known that changes in stimulus features can bias perception in one or another direction, (Klink, et al., 2012). In order to explore this question, we used multi-stable motion stimuli and specifically moving plaids consisting of three superimposed gratings moving in equidistant directions (difference of 120 deg). These stimuli induce the perception of component and pattern motion simultaneously since any two component gratings bind together and are perceived to move in the opposite direction of the third grating component. We modulated properties of the stimuli such as grating speed and size and recorded the responses of human subjects reporting the direction of the single grating using one of three buttons for each direction. Preliminary results show that perceptual dominance is greatly affected by the selection of grating speeds. Grating size did not greatly change the predominance of the different gratings. We find that gratings with speed closer to physiological values have greater probability to be perceived and that gratings with similar speeds tend to group more often than gratings with different speeds. Further manipulations of other stimulus features like contrast and spatial frequency allow parametric variations of the relative probabilities of different interpretations. Our future goal is to use this information to built models of perceptual alternations using probabilistic inference.}, web_url = {http://www.frontiersin.org/10.3389/conf.fncom.2012.55.00058/event_abstract}, event_name = {Bernstein Conference 2012}, event_place = {München, Germany}, state = {published}, DOI = {10.3389/conf.fncom.2012.55.00058}, author = {Li Q{qinglinli}{Department Physiology of Cognitive Processes}, Fleming RW{roland}{Department Human Perception, Cognition and Action}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes} and Keliris GA{george}{Department Physiology of Cognitive Processes}} } @Poster{ GieseCC2012, title = {Perceptual relevance of kinematic components of facial movements extracted by unsupervised learning}, journal = {Perception}, year = {2012}, month = {9}, volume = {41}, number = {ECVP Abstract Supplement}, pages = {150}, abstract = {The idea that complex facial or body movements are composed of simpler components (usually referred to as 'movement primitives'or 'action units') is common in motor control (Chiovetto 2011 Journal of Neurophysiology105(4), 1429-31.) as well as in the study of facial expressions (Ekman and Friesen, 1978). However, such components have rarely been extracted from real facial movement data. Methods: Combining a novel algorithm for anechoic demixing derived from (Omlor and Giese 2011 Journal of Machine Learning Research121111-1148) with a motion retargetting system for 3D facial animation (Curio et al, 2010, MIT Press, 47-65), we estimated spatially and temporally localized components that capture the major part of the variance of dynamic facial expressions. The estimated components were used to generate stimuli for a psychophysical experiment assessing classification rates and emotional expressiveness ratings for stimuli containing combinations of the extracted components. Results: We investigated how the information carried by the different extracted dynamic facial movement components is integrated in facial expression perception. In addition, we tried to apply different cue fusion models to account quantitatively for the obtained experimental results.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v120635}, event_name = {35th European Conference on Visual Perception}, event_place = {Alghero, Italy}, state = {published}, author = {Giese MA{giese}, Chiovetto E and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Poster{ GrauMoya2012, title = {Risk-sensitivity in Bayesian Sensorimotor Integration}, year = {2012}, month = {9}, web_url = {http://www.uni-tuebingen.de/einrichtungen/zentrale-einrichtungen/forum-scientiarum/studium/akademien/archiv/sa-2012-2-decisions.html}, event_name = {Tübingen International Summerschool 2012 (TISS 2012)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Grau-Moya J{jgrau}{Research Group Sensorimotor Learning and Decision-Making}} } @Poster{ delaRosaMBC2012, title = {View dependencies in the visual recognition of social interactions}, journal = {Perception}, year = {2012}, month = {9}, volume = {41}, number = {ECVP Abstract Supplement}, pages = {240}, abstract = {Humans daily physically interact with other people (eg when shaking hands). Understanding the action of others is important for a successful social interaction. Little is known about the visual processes underlying the visual recognition of social interactions. Here we were examined the view dependency of social interaction recognition. We used motion capture to record predefined interactions (eg high five; handshake; hug) acted out by pairs of participants and created 3D models of these interactions. In the actual experiment participants were presented with these interactions one at a time and had to identify a predefined interaction (1IFC task). We manipulated the view point (front, side, top, 45 degree side view) from which participants saw the interaction and the presentation time of the social interactions. We recorded participants'accuracy (as measured by d prime) and reaction time to identify a predefined social interaction. We found that the d primes and reaction time significantly depended on the view point of the social interaction. The results suggest the existence of view dependencies in the visual recognition of social interactions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v120439}, event_name = {35th European Conference on Visual Perception}, event_place = {Alghero, Italy}, state = {published}, author = {de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Miekes S, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Poster{ GianiN2012, title = {Awareness related auditory scene analysis: A processing cascade enables a tone pair to be segregated from background and enter awareness}, year = {2012}, month = {8}, number = {MO-76}, web_url = {http://www.biomag2012.org/}, event_name = {8th International Conference on Biomagnetism (BIOMAG 2012)}, event_place = {Paris, France}, state = {published}, author = {Giani AS{giani}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Poster{ DobsBCS2012, title = {Investigating factors influencing the perception of identity from facial motion}, journal = {Journal of Vision}, year = {2012}, month = {8}, volume = {12}, number = {9}, pages = {35}, abstract = {Previous research has shown that facial motion can convey information about identity in addition to facial form (e.g. Hill & Johnston, 2001). The present study aims at finding whether identity judgments vary depending on the kinds of facial movements and the task performed. To this end, we used a recent facial motion capture and animation system (Curio et al., 2006). We recorded different actors performing classic emotional facial movements (e.g. happy, sad) and non-emotional facial movements occurring in social interactions (e.g. greetings, farewell). Only non-rigid components of these facial movements were used to animate one single avatar head. In a between-subject design, four groups of participants performed identity judgments based on emotional or social facial movements in a same-different (SD) or a delayed matching-to-sample task (XAB). In the SD task, participants watched two distinct facial movements (e.g. happy and sad) and had to choose whether the same or different actors performed these facial movements. In the XAB task, participants saw one target facial movement X (e.g. happy) performed by one actor followed by two facial movements of another kind (e.g. sad) performed by two actors. Participants chose which of the latter facial movements was performed by the same actor as the one performing X. Prior to the experiment, participants were familiarized with the actors by watching them perform facial movements not subsequently tested. Participants were able to judge actor identities correctly in all conditions, except for the SD task performed on the emotional stimuli. Sensitivity to identity as measured by d-prime was higher in the XAB than in the SD task. Furthermore, performance was higher for social than for emotional stimuli. Our findings reveal an effect of task on identity judgments based on facial motion, and suggest that such judgments are easier when facial movements are less stereotypical.}, web_url = {http://www.journalofvision.org/content/12/9/35.abstract}, event_name = {12th Annual Meeting of the Vision Sciences Society (VSS 2012)}, event_place = {Naples, FL, USA}, state = {published}, author = {Dobs K{kdobs}{Department Human Perception, Cognition and Action}, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}, Curio C{curio}{Department Human Perception, Cognition and Action} and Schultz J{johannes}{Department Human Perception, Cognition and Action}} } @Poster{ DobrickiMB2012, title = {Onset time of visually induced circular self-motion perception as an indicator for altered self-localization in immersive virtual reality}, journal = {Journal of Vision}, year = {2012}, month = {8}, volume = {12}, number = {9}, pages = {1326}, abstract = {In the framework of the experimental induction of full-body illusions the features of the experience of being a distinct entity (selfhood) are altered such that participants identify with and mis-localize themselves towards a virtual body. On the other hand, it has been found that the experience of circular self-motion, or vection, can be induced by rotating a naturalistic visual environment around human participants. Circular vection is likely influenced by a person’s self-localization, since it is the illusion of self-rotation around a specific location. Thus, estimates of vection may serve as indicators for altered self-localization. In the framework of a within-subjects design experiment, male participants viewed an avatar from behind within a naturalistic virtual city in a head-mounted display setup. First, we stroked their back for three minutes while they watched the avatar getting synchronously and congruently stroked, or no visuo-tactile stroking was applied (stimulation factor). Subsequently, we assessed their identification with the avatar with a questionnaire, and then repeated the initial treatment. Finally, we rotated the participants’ perspective around their vertical axis for one minute. During rotation the avatar was in the same location in front of the viewer, rotating around his axis, or in a standing posture (avatar-motion factor). Participants were asked to indicate when they started to experience vection. They reported significantly higher identification with the avatar and self-localization in the avatar’s position after visuo-tactile stimulation. Moreover, when they experienced visuo-tactile stimulation, regardless of the avatar-motion factor, participants showed a later onset of vection. One possible explanation for these results is that participants perceived themselves as partially localized in the avatar’s position, and in turn this decrease in their accuracy of self-localization delayed their experience of circular vection. Consequently, we suggest estimates of self-motion as a new measure for selfhood and embodiment, and specifically for self-localization.}, web_url = {http://www.journalofvision.org/content/12/9/1326.abstract}, event_name = {12th Annual Meeting of the Vision Sciences Society (VSS 2012)}, event_place = {Naples, FL, USA}, state = {published}, author = {Dobricki M{mdobricki}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ LinkenaugerMPB2012, title = {The Role of Visual Foot Size in Perceiving Object Size from Texture Gradient}, journal = {Journal of Vision}, year = {2012}, month = {8}, volume = {12}, number = {9}, pages = {902}, abstract = {The ground plane’s texture gradient is a well-known, perspective depth cue that derives from the fact that, for a uniformly textured surface, texture elements become smaller and more densely arrayed in the visual field with increased in distance e.g. grass on a field or cobble stones on a street. This size / distance relationship also occurs for objects such that objects of equal size occlude an equal amount of texture at their base regardless of their distance from the observer. Texture gradients have been studied primarily as a relative depth cue that specifies the size of one object relative to another. However, more definite relative scaling can be achieved if the size of texture elements is scaled to some known metric. We hypothesized that perceivers use the amount of texture occluded by their own feet to scale the sizes of objects on a textured ground. Using head-mounted displays and a motion capture system, we were able to increase or decrease the apparent size of participants’ visual feet in a virtual environment. We asked participants to verbally estimate the width and height of many objects using meters and centimeters(varying in size at the base). As hypothesized, perceivers’ estimations of the sizes of cylinders were smaller when participants had larger virtual feet and larger when participants had smaller virtual feet. This demonstrates that texture gradient, in combination with the visual self-located body, can be used to estimate the size of objects.}, web_url = {http://www.journalofvision.org/content/12/9/902.abstract}, event_name = {12th Annual Meeting of the Vision Sciences Society (VSS 2012)}, event_place = {Naples, FL, USA}, state = {published}, author = {Linkenauger S{sally}{Department Human Perception, Cognition and Action}, Mohler B{mohler}{Department Human Perception, Cognition and Action}, Proffitt D and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ Bulthoff2012_5, title = {What gives a face its ethnicity?}, journal = {Journal of Vision}, year = {2012}, month = {8}, volume = {12}, number = {9}, pages = {1282}, abstract = {We can quickly and easily judge faces in terms of their ethnicity. What is the basis for our decision? Other studies have used either eye tracking (e.g., Armann & Bülthoff 2009) or the Bubbles method (e.g., Gosselin & Schyns 2001) in categorization tasks to investigate which facial features are used for sex or identity classification. The first method investigates which parts are preferentially looked at while the latter method shows which facial regions, when shown in isolation during the task, leads to correct classification. Here we measured the influence of facial features on ethnicity classification when they are embedded in the face of the other ethnicity. Asian and Caucasian faces of our 3D face database (http://faces.kyb.tuebingen.mpg.de) had been paired according to sex, age and appearance. We used 18 pairs of those Asian-Caucasian faces to create a variety of mixed-race faces. Mixed-race faces were obtained by exchanging one of the following facial features between both faces of a pair: mouth, nose, facial contour, shape, texture (skin) and eyes. We showed original and modified faces one by one in a simple ethnicity classification task. All faces were turned 20 degrees to the side for a more informative view of nose shape, face shape and facial contour while eyes and mouth and general face textures were still fully visible. Because of skin color differences between exchanged parts and original faces, all 3D faces were rendered as grey-level images. The results of 24 Caucasian participants show that the eyes and the texture of a face are major determinants for ethnicity classification, more than face shape and face contour, while mouth and nose had weak influence. Response times showed that participants were faster at classifying less ambiguous faces.}, web_url = {http://www.journalofvision.org/content/12/9/1282.abstract}, event_name = {12th Annual Meeting of the Vision Sciences Society (VSS 2012)}, event_place = {Naples, FL, USA}, state = {published}, author = {B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Poster{ EsinsSKWB2012, title = {Comparing the other-race-effect and congenital Prosopagnosia using a three-experiment test battery}, year = {2012}, month = {7}, volume = {8}, pages = {57}, abstract = {Congenital prosopagnosia, an innate impairment in recognizing faces, as well as the other-race-effect, the disadvantage in recognizing faces of foreign races, both influence face recognition abilities. Here we compared both phenomena by testing three groups: German congenital prosopagnosics (cPs), unimpaired German and unimpaired South Korean participants (n=23 per group), on three tests with Caucasian faces. First we ran the Cambridge Face Memory Test (Duchaine & Nakayama, 2006 Neuropsychologia 44 576-585). Participants had to recognize Caucasian target faces in a 3AFC task. German controls performed better than Koreans (p=0.009) who performed better than prosopagnosics (p=0.0001). Variation of the individual performances was larger for cPs than for Koreans (p = 0.028). In the second experiment, participants rated the similarity of Caucasian faces (in-house 3D face-database) which differed parametrically in features or second order relations (configuration). We found differences between sensitivities to change type (featural or configural, p=0) and between groups (p=0.005) and an interaction between both factors (p = 0.019). During the third experiment, participants had to learn exemplars of artificial objects (greebles), natural objects (shells), and faces and recognize them among distractors. The results showed an interaction (p = 0.005) between stimulus type and participant group: cPs where better for non-face stimuli and worse for face stimuli than the other groups. Our results suggest that congenital prosopagnosia and the other-race-effect affect face perception in different ways. The broad range in performance for the cPs directs the focus of our future research towards looking for different forms of congenital prosopagnosia.}, file_url = {fileadmin/user_upload/files/publications/2012/APCV-2012-Poster-Esins.pdf}, web_url = {http://apcv2012.com/}, event_name = {8th Asia-Pacific Conference on Vision (APCV 2012)}, event_place = {Incheon, South Korea}, state = {published}, author = {Esins J{esins}{Department Human Perception, Cognition and Action}, Schultz J{johannes}{Department Human Perception, Cognition and Action}, Kim BR, Wallraven C{walli}{Department Human Perception, Cognition and Action} and B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Poster{ JungAB2012, title = {What gives a face its race?}, year = {2012}, month = {7}, volume = {8}, pages = {60}, abstract = {What gives a face its race?By biological criteria, human “races” do not exist (e.g., Cosmides et al., 2003). Nevertheless, every-day life and research from various fields show that we robustly and reliably perceive humans as belonging to different race groups. Here, we investigate the bases for our quick and easy judgments, by measuring the influence of manipulated facial features on race classification. Asian and Caucasian faces of our 3-dimensional face database (http://faces.kyb.tuebingen.mpg.de) were paired according to sex, age and overall appearance. With these Asian-Caucasian face pairs we created a variety of mixed-race faces, by exchanging facial features between both faces of a pair: eyes, nose, mouth, “outer” features, shape or texture. Original and modified faces were shown in a simple race classification task. We tested 24 Westerners (Germany) and 24 Easterners (South Korea). In both groups, eyes and texture were major determinants for race classification, followed by face shape, and then outer features, mouth, nose, which only had a weak influence on perceived face. Eastern participants classified Caucasian original faces better than Asian original faces, while Western participants were similarly good at classifying both races. Western participants - but not their Eastern counterparts - were less susceptible to eye, shape and texture manipulations in other-race faces than in their own-race faces. A closer look at the data suggests that this effect mainly originates from differences in processing male and female faces in Western participants only. Our results provide more evidence of differences between observers from different cultural and ethnic backgrounds in face perception and processing.}, file_url = {fileadmin/user_upload/files/publications/2012/APCV-2012-Jung.pdf}, web_url = {http://apcv2012.com/}, event_name = {8th Asia-Pacific Conference on Vision (APCV 2012)}, event_place = {Incheon, South Korea}, state = {published}, author = {Jung W, Armann R{armann}{Department Human Perception, Cognition and Action} and B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Poster{ NestiBBP2012, title = {Roll rate thresholds in driving simulation}, journal = {Seeing and Perceiving}, year = {2012}, month = {6}, day = {21}, volume = {25}, number = {0}, pages = {167}, abstract = {The restricted operational space of dynamic driving simulators requires the implementation of motion cueing algorithms that tilt the simulator cabin to reproduce sustained accelerations. In order to avoid conflicting inertial cues, the tilt rate is limited below drivers’ perceptual thresholds, which are typically derived from the results of classical vestibular research, where additional sensory cues to self-motion are removed. These limits might be too conservative for an ecological driving simulation, which provides a variety of complex visual and vestibular cues as well as demands of attention which vary with task difficulty. We measured roll rate detection threshold in active driving simulation, where visual and vestibular stimuli are provided as well as increased cognitive load from the driving task. Here thresholds during active driving are compared with tilt rate detection thresholds found in the literature (passive thresholds) to assess the effect of the driving task. In a second experiment, these thresholds (active versus passive) are related to driving preferences in a slalom driving course in order to determine which roll rate values are most appropriate for driving simulators so as to present the most realistic driving experience. The results show that detection threshold for roll in an active driving task is significantly higher than the limits currently used in motion cueing algorithms, suggesting that higher tilt limits can be successfully implemented to better optimize simulator operational space. Supra-threshold roll rates in the slalom task are also rated as more realistic. Overall, our findings indicate that increasing task complexity in driving simulation can decrease motion sensitivity allowing for further expansion of the virtual workspace environment.}, web_url = {http://booksandjournals.brillonline.com/content/10.1163/187847612x647973}, event_name = {13th International Multisensory Research Forum (IMRF 2012)}, event_place = {Oxford, UK}, state = {published}, DOI = {10.1163/187847612X647973}, author = {Nesti A{ale}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Pretto P{pretto}{Department Human Perception, Cognition and Action}} } @Poster{ Bulthoff2012_3, title = {Persistent perceptual delay for head movement onset relative to auditory stimuli of different duration and rise times}, journal = {Seeing and Perceiving}, year = {2012}, month = {6}, day = {19}, volume = {25}, number = {0}, pages = {32}, abstract = {The perception of simultaneity between auditory and vestibular information is crucially important for maintaining a coherent representation of the acoustic environment whenever the head moves. Yet, despite similar transduction latencies, vestibular stimuli are perceived significantly later than auditory stimuli when simultaneously generated (Barnett-Cowan and Harris, 2009; 2011). However, these studies paired a vestibular stimulation of long duration (~1 s) and of a continuously changing temporal envelope with brief (10-50 ms) sound pulses. In the present study the stimuli were matched for temporal envelope. Participants judged the temporal order of the onset of an active head movement and of brief (50 ms) or long (1400 ms) sounds with a square or raised-cosine shaped envelope. Consistent with previous reports, head movement onset had to precede the onset of a brief sound by about 73 ms in order to be perceived as simultaneous. Head movements paired with long square sounds (~100ms) were not significantly different than brief sounds. Surprisingly, head movements paired with long raised-cosine sound (~115 ms) had to be presented even earlier than brief stimuli. This additional lead time could not be accounted for by differences in the comparison stimulus characteristics (duration and temporal envelope). Rather, differences among sound conditions were found to be attributable to variability in the time for head movement to reach peak velocity: the head moved faster when paired with a brief sound. The persistent lead time required for vestibular stimulation provides further evidence that the perceptual latency of vestibular stimulation is larger compared to auditory stimuli.}, web_url = {http://booksandjournals.brillonline.com/content/10.1163/187847612x646541}, event_name = {13th International Multisensory Research Forum (IMRF 2012)}, event_place = {Oxford, UK}, state = {published}, DOI = {10.1163/187847612X646541}, author = {Raeder S{sophie13}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}} } @Poster{ PerdikisMKWL2012, title = {EEG brain dynamics during processing of static and dynamic facial emotional expression}, year = {2012}, month = {5}, abstract = {Humans recognize facial emotional expressions (FEEs) better when FEEs are presented dynamically than through static images. Wallraven et al. 2008 propose that humans are sensitive to the natural dynamics of FEEs. Moreover, PET/fMRI studies suggest that differentiated brain networks process static and dynamic FEEs. However, in most cases, dynamic FEEs have been created out of static ones, using linear morphing techniques. Together with the low time resolution of PET/fMRI, such studies fail to capture the modulation of the activated brain networks by the subtle (and highly nonlinear) dynamics of FEEs. Our ongoing study investigates EEG responses to static and dynamic FEEs drawn from an ecologically valid database (Kaulard et al. 2008, Kaulard et al. 2009). “Happy” and “angry” FEEs performed by two male and two female actors are displayed to twenty female participants in an “oddball” experimental paradigm. Blocks of either dynamic or static stimuli that differ in their emotional content (“happy” versus “angry” and reverse) are presented in a pseudorandom order. The task consists of pressing a keyboard button upon appearance of a deviant stimulus. Data analysis focuses on synchrony and nonlinear coupling of sensor as well as source dynamics (as a bridge to PET/fMRI studies), both in the time-frequency and in the phase-space domain, to identify the brain networks that emerge and evolve dynamically in each condition. Preliminary results from pilot data analysis confirm the PET/fMRI findings of enhanced and differentiated brain activations for dynamic FEEs compared to static ones.}, web_url = {http://escan2012.sciencesconf.org/4021}, event_name = {1st Conference of the European Society for Cognitive and Affective Neuroscience (ESCAN 2012)}, event_place = {Marseille, France}, state = {published}, author = {Perdikis D, M\"uller V, Kaulard K{kascot}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action} and Lindenberg U} } @Poster{ NestiBMB2012, title = {Differential Thresholds for Vertical Motion}, year = {2012}, month = {1}, volume = {22}, number = {12}, web_url = {http://www.vertigocenter.ch/ZuMu2012/pres.html#Posters}, event_name = {22nd Okulomotoriktreffen Zürich-München (ZüMü 2012)}, event_place = {Zürich, Switzerland}, state = {published}, author = {Nesti A{ale}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, MacNeilage P{pogen} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ SoykaRBB2012, title = {Reaction Times for Self-Motion Detection}, year = {2012}, month = {1}, volume = {22}, number = {14}, web_url = {http://www.vertigocenter.ch/ZuMu2012/pres.html#Posters}, event_name = {22nd Okulomotoriktreffen Zürich-München (ZüMü 2012)}, event_place = {Zürich, Switzerland}, state = {published}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Thesis{ Nieuwenhuizen2012, title = {Changes in pilot control behaviour across Stewart platform motion systems}, year = {2012}, month = {7}, day = {4}, file_url = {fileadmin/user_upload/files/publications/2012/Nieuwenhuizen-Diss-2012.pdf}, web_url = {http://repository.tudelft.nl/view/ir/uuid%3A81b63869-6048-456d-99d2-aeade8da8ad2/}, state = {published}, type = {PhD}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2012_12, title = {Flying Robots and Flying Cars}, year = {2012}, month = {12}, day = {12}, file_url = {fileadmin/user_upload/files/publications/2012/KAIST-2012-key.pdf}, web_url = {http://rslab.kaist.ac.kr/xe/?document_srl=626#0}, event_name = {Korea Advanced Institute of Science and Technology: Robotics and Simulation Laboratory}, event_place = {Daejeon, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ NieuwenhuizenBM2012, title = {Changes in Pilot Control Behaviour across Stewart Platform Motion Systems}, year = {2012}, month = {11}, day = {29}, abstract = {Low-cost motion systems have been proposed for certain training tasks that would otherwise be performed on high-performance full flight simulators. These systems have shorter stroke actuators, lower bandwidth, and higher noise. The influence of these characteristics on pilot perception and control behaviour is unknown, and can be investigated by simulating a model of a simulator with limited capabilities on a high-end simulator. The platform limitations, such as a platform filter, time delay, and simulator noise characteristics, can then be removed one by one and their effect on control behaviour studied in isolation. By applying a cybernetic approach, human behaviour can be measured objectively in target-following disturbance-rejection control tasks. Experimental results show that small changes in time delay and simulator noise characteristics do not negatively affect human behaviour in these tasks. However, the motion system bandwidth has a significant effect on performance and control behaviour. Participants barely use motion cues when these have a low bandwidth, and instead rely on visual cues to generate lead to perform the control task. Therefore, simulator motion cues must be considered carefully in piloted control tasks in simulators and measured results depend on simulator characteristics as pilots adapt their control behaviour to the available cues.}, file_url = {fileadmin/user_upload/files/publications/2012/Flight-Simulation-Research-2012-Nieuwenhuizen.pdf}, web_url = {http://aerosociety.com/Events/Event-List/258/Flight-Simulation-Research-Conference}, event_name = {Autumn Flight Simulation Conference: Flight Simulation Research New Frontiers}, event_place = {London, UK}, state = {published}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mulder M} } @Conference{ Bulthoff2012_11, title = {Cognitive Science and its Impact on Future Convergence Technology}, year = {2012}, month = {11}, day = {26}, web_url = {http://convergence.geni-pco.com/}, event_name = {Future Convergence Technology Forum & Exhibition 2012}, event_place = {Seoul, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Curio2012_2, title = {Fusion of Human- and Machine-Vision: Research, Tools and Applications for Driving Assistance}, year = {2012}, month = {11}, day = {18}, event_name = {Bosch R&D}, event_place = {Hildesheim, Germany}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2012_10, title = {What Computer Vision and Computer Graphics can learn about Faces from Human Psychophysics}, year = {2012}, month = {11}, day = {6}, web_url = {http://users.cs.cf.ac.uk/Paul.Rosin/faceworkshop2012/invited.html}, event_name = {ACCV 2012 Workshop on Face Analysis: The Intersection of Computer Vision and Human Perception}, event_place = {Daejeon, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Chuang2012, title = {Active Information Retrieval in Scene Perception and Object Learning}, year = {2012}, month = {11}, day = {2}, abstract = {We pick out task-relevant information from the visual scene by moving our eyes and confidently manipulate our near-environment to achieve our goals. A better understanding of human behavior can be achieved by adopting this perspective. That is, humans are active (not passive observers). In my talk, I will address how we characterize natural information-seeking behavior in human participants in two context: a) scene processing, b) object learning. The first addresses how unrestrained gaze behavior can be characterized in terms of the information that is available in the scene. Here, I will explain why and how we eschew pure bottom-up procedures of using low-level image statistics to predict gaze movements. Next, I will discuss how we select which views of unfamiliar objects to learn, when we are free to manipulate them in 3D.}, event_name = {Department of Cognitive Neuroscience: Duke-NUS Graduate Medical School}, event_place = {Singapore}, state = {published}, author = {Chuang L{chuang}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2012_4, title = {Control and Estimation for Decentralized Multi-robot Systems}, year = {2012}, month = {11}, event_name = {Heudiasyc - CNRS - Université de Technologie de Compiègne}, event_place = {Compiègne, France}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ Soyka2012, title = {Modeling Self-Motion Perception based on the Vestibular System}, year = {2012}, month = {11}, volume = {13}, pages = {13}, abstract = {Understanding self-motion perception is important, e.g., for developing perception-based diagnostics for patients suffering from vestibular disorders, or for improving the realism of motion simulation. Here, self-motion perception was quantified with direction discrimination thresholds and reaction times for translational and rotational motions. Models based on the physiology of the vestibular system, which plays a central role in sensing inertial motions, are introduced that are able to describe psychophysical measurements. The Max Planck Institute CyberMotion Simulator was used to measure thresholds for 9 translational and 9 rotational motion stimuli with varying acceleration profiles. A forced-choice paradigm was used in which blindfolded participants had to judge the directions of motions with varying peak accelerations until the threshold acceleration was found that yielded a predefined performance level (e.g. 75% correct answers). A similar task was used with supra threshold accelerations in order to measure reaction times for 4 translational and 4 rotational motions. The results show that thresholds and reaction times depend on the actual shape and duration of an acceleration profile. The proposed models were fit to threshold measurements and are able to describe thresholds for arbitrary motion profiles. In accordance with previous research, the estimated model parameters indicate that velocity storage does not influence rotational thresholds. For translational motions, it was found that the sensitivity to jerk (the time derivative of acceleration) is higher than previously assumed. Furthermore, the models identified based on threshold measurements are able to predict differences between reaction times for varying motion profiles measured in another group of participants. This is an important finding, because it links reaction times and threshold measurements. Therefore, future research will be able to identify self-motion perception models based on reaction times. This is advantageous, since reaction time tasks are more convenient for participants and require fewer trials, allowing for faster testing.}, web_url = {http://www.neuroschool-tuebingen-nena.de/}, event_name = {13th Conference of the Junior Neuroscientists of Tübingen (NeNA 2012)}, event_place = {Schramberg, Germany}, state = {published}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}} } @Conference{ VolkovaMB2012, title = {Motion Capture of Emotional Body Language in Narrative Scenarios}, year = {2012}, month = {11}, volume = {13}, pages = {9}, abstract = {We interact with the world we live in by moving in it. The interaction is versatile and includes communications through speech and gestures, which serve as media to transmit ideas and emotions. A narrator, be it a professional actor on the stage or a friend telling an anecdote, expresses her ideas (the content) and feelings (the emotional colouring) through the choice of words and syntactical structures, her prosody, facial expressions and body language. Our present focus is on emotional body language, which became a field of intensive research several decades ago. Before psychopsysical experiments or trajectory analysis can take place, a set of mocap (motion capture) data has to be accumulated. This can be done with different equipment setups and by now human motion can be captured fairly precisely at a high frame rate. One of the major decisions for the researchers however is the choice of scenarios according to which the actors are to perform motion. This question is especially tricky when we deal with emotions, since the problems of sincerity and naturalness come into play. There are several ways to induce emotions and moods in people, but for motion capture the socalled imagination technique has been used most frequently. The actors are asked to evoke an emotion in themselves by recalling a past event. The main drawbacks of this technique in mocap are the following: (1) it is still impossible to ensure that the emotions are sincere and the motion is natural and not artificial or exaggerated; (2) the emotional categories often rapidly succeed each other in random fashion; (3) the emotional scenarios can be very abstract and taken out of context.We have developed an experimental setup where the emotional body language can be captured in a maximally natural yet controlled manner. The participants are asked to imagine they are narrating a fairy-tale to children. They perform several tasks on the text before their acting in recorded. The setup allows the actors to narrate the story at their own pace, move freely and does not require them to learn the text by heart, yet the recorded data can be easily extracted and processed after the motion capture session. The resulting extracted data can then analysed for various features or used in perceptual experiments.}, web_url = {http://www.neuroschool-tuebingen-nena.de/}, event_name = {13th Conference of the Junior Neuroscientists of Tübingen (NeNA 2012)}, event_place = {Schramberg, Germany}, state = {published}, author = {Volkova EP{evolk}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ DwarakanathPHE2012, title = {Motion parallax serves as an independent cue in sound source disambiguation}, year = {2012}, month = {11}, volume = {13}, pages = {6}, abstract = {In the absence of dominant cues to the distance of a sound source from the observer, estimating absolute or relative distance becomes difficult. Motion parallax may contribute to this estimation. However, its role as an independent cue has not yet been investigated. To address this issue, we designed an experiment that included logarithmically varying distance of sound source along the depth plane of the observer, elimination of distance related loudness using perceptual loudness equalization and to and fro (laterally) movement of subjects while the sounds were generated in three conditions a simultaneous playback, sequential playback and simultaneous playback of phase-interrupted sounds. Sequential presentation of the low and high sound subjects showed a substantial improvement in distance estimates relative to the baseline static condition. Improvement was also observed for the simultaneous phase interrupted sound condition. Here we demonstrate for the first time the existence of auditory motion parallax from lateral self- motion and show that it aids distance estimation of sound position. Interestingly, a bias to perceive low frequency sounds as farther away was also observed. Auditory depth perception is improved by lateral observer motion, which alters the inter-aural difference cues available.}, web_url = {http://www.neuroschool-tuebingen-nena.de/}, event_name = {13th Conference of the Junior Neuroscientists of Tübingen (NeNA 2012)}, event_place = {Schramberg, Germany}, state = {published}, author = {Dwarakanath A{adwarakanath}{Research Group Physiology of Sensory Integration}, Parise C{cesare}{Research Group Multisensory Perception and Action}, Hartcher-O'Brien J{jhartcher}{Research Group Multisensory Perception and Action} and Ernst M{marc}{Research Group Multisensory Perception and Action}} } @Conference{ NieuwenhuizenCB2012, title = {myCopter: Enabling Technologies for Personal Aerial Transportation Systems A progress report}, year = {2012}, month = {11}, abstract = {The volume of both road and air transportation continues to increase despite many concerns regarding its financial and environmental impact. The European Union ‘Out of the Box’ study suggests a personal aerial transportation system (PATS) as an alternative means of transport for daily commuting. The aim of the myCopter project is to determine the social and technical aspects needed to set up such a transportation system based on personal aerial vehicles (PAVs). The project focuses on three research areas: the human-machine interface and training, automation technologies, and social acceptance. In the first phase of the project, requirements were defined for automation technologies in terms of sensors and test platforms. Additionally, desirable features for PAVs were investigated to support the design and evaluation of technologies for an effective human-machine interface. Furthermore, an overview of the social-technological environment provided insight into the challenges and issues that surround the realisation of a PATS and its integration into the current transportation system in Europe. The presentation will elaborate on the second phase of the myCopter project, in which initial designs for a human-machine interface and training are developed. These are evaluated experimentally with a focus on aiding non-expert pilots in closed-loop control scenarios. Additionally, first evaluations of novel automation technologies are performed in simulated environments and evaluations on flying test platforms. At the same time, technological issues are evaluated that contribute towards a reflexive design of PAV technologies based on criteria that are acceptable to the general public. The presentation will also focus on the next stages of the project, in which further experimental evaluations will be performed on technologies for human-machine interfaces, and where developed automation technologies will be fully tested on unmanned flying vehicles. The expectations and perspectives of potential PAV user will be evaluated in group interviews in different European countries. Interesting technological and regulatory challenges need to be resolved for the development of a transportation system based on PAVs. The myCopter consortium combines the expertise from several research fields to tackle these challenges and to develop the technological and social aspects of a personal aerial transportation system.}, file_url = {fileadmin/user_upload/files/publications/2012/HELIWorld-2012-Nieuwenhuizen.pdf}, event_name = {4th International HELI World Conference at the International Aerospace Supply Fair AIRTEC 2012}, event_place = {Frankfurt a.M., Germany}, state = {published}, author = {Nieuwenhuizen F{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, Chuang L{chuang}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Streuber2012, title = {The influence of different sources of visual information on joint action performance}, year = {2012}, month = {11}, volume = {13}, pages = {21}, abstract = {Humans are social beings and they often act jointly together with other humans (joint actions) rather than alone. Successful joint action requires the understanding and the coordination of ones own actions with another persons actions. The research attempts to advance our knowledge about joint action coordination by extending existing research in two novel and important ways. First, prominent theories of joint action agree on visual information being critical for successful joint action coordination but are vague about the exact source of visual information being used during a joint action. However, in a real life interaction several sources of visual information exist which inform an interaction partner about the ongoing course of the interaction (e.g. visual information about objects, tools, other persons). Knowing which sources of visual information are used, however, is important for a more detailed characterization of the functioning of action coordination in joint actions. Second, previous studies investigating the role of visual information in social settings often constrain the experimental tasks to artificial laboratory settings. To examine joint action mechanisms under realistic conditions I devised experimental tasks that allowed a close-to-natural joint action. As a result the perceptual and motor components of the experimental tasks were less constrained allowing for a more natural interaction compared to previous studies. The current research examines the importance of different sources of visual information on joint action coordination under realistic settings. In three studies I examined the influence of different sources of visual information (Study 1), the functional role of different sources of visual information (Study 2), and the effect of social context on the use of visual information (Study 3) in a table tennis game. The results of these studies revealed that (1) visual anticipation of the interaction partner and the interaction object is critical in natural joint actions, (2) different sources of visual information are critical at different temporal phases during the joint action, and (3) the social context modulates the importance of different sources of visual information. In sum, this work provides important and new empirical evidence about the importance of different sources of visual information in close-to-natural joint actions.}, web_url = {http://www.neuroschool-tuebingen-nena.de/}, event_name = {13th Conference of the Junior Neuroscientists of Tübingen (NeNA 2012)}, event_place = {Schramberg, Germany}, state = {published}, author = {Streuber S{stst}{Department Human Perception, Cognition and Action}} } @Conference{ GianiN2012_2, title = {Towards multisensory awareness: Finding (neuronal) mechanisms that enable the detection and integration of audiovisual stimuli}, year = {2012}, month = {11}, volume = {13}, pages = {8}, abstract = {In daily life our sensory systems continuously receive complex information from different sensory modalities, such as vision, audition or touch. To form unified and coherent percepts this information needs to be integrated across the various senses; a process called multisensory integration. Multisensory information stemming from natural environments, such as market places or busy roads, can be extremely diverse. Moreover limited processing capacities allow only a small subset of the complex sensory information to enter awareness. Hence, two main questions arise: Which are the (neuronal) mechanisms that enable sensory awareness? And is perceptual awareness necessary for multisensory integration to occur? During my PhD I used magnetoencephalography (MEG) and psychophysical measurements, trying to find some answers to these questions, which I will be presenting during this talk.}, web_url = {http://www.neuroschool-tuebingen-nena.de/}, event_name = {13th Conference of the Junior Neuroscientists of Tübingen (NeNA 2012)}, event_place = {Schramberg, Germany}, state = {published}, author = {Giani A{giani}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Conference{ NieuwenhuizenB2012, title = {myCopter – Enabling Technologies for Personal Aerial Transportation Systems}, year = {2012}, month = {10}, day = {24}, web_url = {http://ec.europa.eu/research/transport/news/items/joint_eu_us_workshop_en.htm}, event_name = {Joint EU–US Workshop on Small Aircraft and Personal Planes Systems}, event_place = {Brussels, Belgium}, state = {published}, author = {Nieuwenhuizen F{fmnieuwenhuizen}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Nieuwenhuizen2012_2, title = {Assessing Pilot Behaviour in Closed-loop Environments}, year = {2012}, month = {10}, day = {18}, event_name = {2nd Simulator Oriented Flight Training Workshop: Deutsches Zentrum für Luft- und Raumfahrt}, event_place = {Braunschweig, Germany}, state = {published}, author = {Nieuwenhuizen F{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2012_8, title = {A Cybernetics Approach to Perception and Action}, year = {2012}, month = {10}, day = {15}, web_url = {http://www.smc2012.org/program/index.php/program/glance}, event_name = {IEEE International Conference on Systems, Man, and Cybernetics (SMC 2012)}, event_place = {Seoul, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2012_9, title = {The MPI View on Shared Control}, year = {2012}, month = {10}, day = {14}, web_url = {http://cnbisrv02.epfl.ch/~tcarlson/smc2012wsc/index.html}, event_name = {SMC 2012 Workshop on Shared Control}, event_place = {Seoul, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Curio2012, title = {Fusing Human- and Machine-Vision for Enhanced Driver Perception and Decision Making}, year = {2012}, month = {10}, day = {12}, event_name = {Environment Perception Group, Daimler AG}, event_place = {Ulm, Germany}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2012_7, title = {Flying Robots and Flying Cars}, year = {2012}, month = {10}, day = {10}, abstract = {We all know that our brain is constantly processing a vast amount of sensory and intrinsic information with which our behavior is coordinated accordingly. Interestingly, how the brain actually does it is less well understood. At the Max Planck Institute for Biological Cybernetics in Germany we aim to best model human perception and action and to test these models to predict human action for example in the context of driving and flying. To this end, we use systems and control theory, computer vision, and psychophysical techniques while conducting experiments with the most advanced state of the art motion simulators. In my talk I will present two examples that illustrate our research philosophy: (1) a telepresence scenario with flying robots (quadcopters) in which we study new ways to interface human operators and teams of autonomous remote robots in a shared bilateral control architecture. (2) a futuristic transportation scenario based on a European project (www.mycopter.eu) in which we are studying the enabling technologies for flying between homes and work place in swarms at low altitude. Our efforts are guided by the vision that in the future humans and machines will seamlessly cooperate in shared or remote spaces, and thus robots or flying cars become an integral part of our daily life.}, web_url = {http://cic.korea.ac.kr/kor/sub/sub01_03.php?mode=view&mNum=&sNum=3&idx=212}, event_name = {College of Information and Communications: Korea University}, event_place = {Seoul, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ ButlerDNWBRF2012, title = {High-density electrical mapping during active and passive self-motion}, year = {2012}, month = {10}, volume = {42}, number = {828.06}, abstract = {The perception of self-motion is a product of the integration of information from both visual and nonvisual cues, to which the vestibular system is a central contributor. It is well documented that self-motion dysfunction leads to impaired movement and balance, dizziness and falls, and yet our knowledge of the neuronal processing of self-motion signals remains relatively sparse. Here we present two studies extending an emerging line of research trying to obtain electroencephalographic (EEG) recordings while participants engage in real-world tasks. The first study investigated the feasibility of acquiring high-density event-related brain potential (ERP) recordings during treadmill walking. Participants performed a visual response inhibition task - designed to evoke a P3 component for correct response inhibitions and an error-related negativity (ERN) for incorrect commission errors - while speed of walking was experimentally manipulated. Robust P3 and ERN components were obtained under all experimental conditions - while participants were stationary, walking at moderate speed (2.4 km/hour), or walking rapidly (5km/hour). Signal-to-noise ratios were remarkably similar across conditions, pointing to the feasibility of high-fidelity ERP recordings under relatively vigorous activity regimens. In the second study, high-density electroencephalographic recordings were deployed to investigate the neural processes associated with vestibular detection of changes in heading. Participants were translated linearly 7.8 cm on a motion platform using a one second motion profile, at a 45 angle leftward or rightward of straight ahead. These headings were presented with a stimulus probability of 80-20 %. Participants responded when they detected the infrequent direction change via button-press. Statistical parametric mapping showed that ERP to standard and target movements differed significantly from 490 to 950 ms post-stimulus. Topographic analysis showed that this difference had a typical P3 topography. These studies provide highly promising methods for gaining insight into the neurophysiological correlates of self-motion in more naturalistic environmental settings.}, web_url = {http://www.sfn.org/am2012/}, event_name = {42nd Annual Meeting of the Society for Neuroscience (Neuroscience 2012)}, event_place = {New Orleans, LA, USA}, state = {published}, author = {Butler JS{butler}{Department Human Perception, Cognition and Action}, Desanctis P, Nolan H, Whelan R, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Reilly O and Foxe J} } @Conference{ Franchi2012_5, title = {Multiple-robot systems: Decentralized Control and Estimation with Diverse Topological Requirements}, year = {2012}, month = {10}, event_name = {Laboratoire d'Informatique, de Robotique et de Microélectronique de Montpellier (UM2-CNRS)}, event_place = {Montpellier, France}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ Venrooij2012_2, title = {What if we simply fly to work? myCopter – Enabling Technologies for Personal Aerial Transportation Systems}, year = {2012}, month = {9}, day = {26}, file_url = {fileadmin/user_upload/files/publications/2012/myCopter-Presentation-Venrooij.pdf}, event_name = {Deutsch-Italienische Handelskammer: Workshop zur Investorengewinnung}, event_place = {Vicenza, Italy}, state = {published}, author = {Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}, Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Venrooij2012, title = {What if we simply fly to work? myCopter – Enabling Technologies for Personal Aerial Transportation Systems}, year = {2012}, month = {9}, day = {25}, file_url = {fileadmin/user_upload/files/publications/2012/myCopter-Presentation-Venrooij.pdf}, event_name = {Deutsch-Italienische Handelskammer: Workshop zur Investorengewinnung}, event_place = {Torino, Italy}, state = {published}, author = {Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}, Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2012_6, title = {Decentralized Control and Estimation in Multi-robot Systems with Diverse Topological Requirements}, year = {2012}, month = {9}, day = {20}, abstract = {This talk will give an overview of some theoretical and experimental results in the multi-robot field, with a special regard to the multi-UAV case. The major strengths of a multi-robot system are both the resilience to single point failures and the possibility of parallelizing the execution of a given task. These properties can be fully exploited in coverage-like tasks, e.g., exploration, pursuit-evasion (a.k.a. "clearing"), and periodical monitoring (a.k.a. "patrolling"). These tasks, in turn, contain several control and estimation subproblems, e.g., how to:- keep a certain optimal arrangement by using an appropriate formation controller, that should be decentralized and using of cheap and lightweight sensors; - keep some topological properties of the interaction, like the connectivity and the rigidity of the group, while still allowing for a flexible behavior of the robots, i.e., a time-varying topology, and decentralization; - mutually localize the robots in order to allow a proper fusion of the information gained by every single robot. The common and particularly challenging situation where the robot-to-robot sensor is anonymous, i.e., it does not retrieve the identity of the detected robot, will be considered; - allow the presence of one or more human co-operators in order to cope with particularly challenging tasks, where cognitive capabilities are required, e.g., in search and rescue operations. A relevant problem in this shared control case is how to balance the robot autonomy with the human assistance. - cope with the uncertainty in the robotic system and in the interacting environment in order to effectively employ actual multi-robot systems in the real-world scenarios.}, web_url = {http://www.laas.fr/1-31318-Detail.php?id=876}, event_name = {Laboratoire d'Analyse et d'Architecture des Systèmes (LAAS-CNRS)}, event_place = {Toulouse, France}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ BulthoffN2012, title = {„Und wenn wir einfach zur Arbeit fliegen“ – Sind fliegende Autos ein Verkehrsmittel der Zukunft?}, year = {2012}, month = {9}, day = {18}, abstract = {Ein allmorgendliches Szenario: Stau auf den Autobahnen, die Hauptverkehrsstraßen der Städte sind verstopft, Züge und Busse sind hoffnungslos überfüllt. Der Pendlerverkehr ist längst an seine Grenzen gestoßen und Abhilfe kann der Ausbau des bestehenden Verkehrsnetzes nur noch bedingt schaffen. Vielerorts fehlt es einfach an dem benötigten Platz für neue Straßen und auch die Instandhaltung bestehender kostet schon Unsummen. Doch wie sehen die Alternativen aus? Ganz einfach: Der Individualverkehr hebt ab in die dritte Dimension! Diese Vision verfolgt Prof. Heinrich Bülthoff vom Max-Planck-Institut für biologische Kybernetik in Tübingen mit dem EU-Projekt „myCopter“. Ziel ist nicht, ein fliegendes Auto zu bauen, sondern vielmehr die technischen und gesellschaftlichen Bedingungen zu klären, unter denen diese zu einem von der Gesellschaft akzeptierten und brauchbaren Verkehrsmittel werden könnten. Damit wird – in hoffentlich nicht allzu ferner Zukunft - unser Weg zur Arbeit wieder entspannter sein. Zum Konsortium gehören neben dem MPI für biologische Kybernetik, die Universität Liverpool, die École Polytechnique in Lausanne, die ETH Zürich, das Karlsruher Institut für Technologie und das Deutsche Zentrum für Luft- und Raumfahrt.}, web_url = {http://gdnae.wordpress.com/2012/08/16/und-wenn-wir-einfach-zur-arbeit-fliegen-sind-fliegende-autos-ein-verkehrsmittel-der-zukunft/}, event_name = {127. Versammlung der Gesellschaft Deutscher Naturforscher und Ärzte e.V. (GDNÄ)}, event_place = {Göttingen, Germany}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Nieuwenhuizen F{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2012_6, title = {What do we read from a face? The role culture and expertise}, year = {2012}, month = {9}, day = {14}, web_url = {http://eewseng.kaist.ac.kr/kor/board.php?db=announcements&no=247&c=view}, event_name = {2012 World Class University International Conference (WCU IC)}, event_place = {Seoul, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ DobrickiMB2012_3, title = {The ownership of a virtual body induced by visuo-tactile stimulation indicates the alteration of self-boundaries}, year = {2012}, month = {9}, day = {7}, web_url = {http://w3.uniroma1.it/icsc/2012/}, event_name = {5th International Conference on Spatial Cognition (ICSC 2012)}, event_place = {Roma, Italy}, state = {published}, author = {Dobricki M{mdobricki}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Ryll2012, title = {Overactuation in UAVs – Modeling and Control of a Quadrotor with Tilting Propellers}, year = {2012}, month = {9}, day = {6}, web_url = {http://dgr.robotics.tu-berlin.de/index.php?option=com_content&view=article&id=58&Itemid=71}, event_name = {DGR-Tage 2012 (Deutsche Gesellschaft für Robotik): Technische Universität Berlin}, event_place = {Berlin, Germany}, state = {published}, author = {Ryll M{maryll}{Department Human Perception, Cognition and Action}} } @Conference{ Pretto2012, title = {Roll rate thresholds and perceived realism in driving simulation}, year = {2012}, month = {9}, day = {6}, web_url = {http://dsc2010.ensam.eu/}, event_name = {Driving Simulation Conference Europe (DSC 2012)}, event_place = {Paris, France}, state = {published}, author = {Pretto P{pretto}{Department Human Perception, Cognition and Action}} } @Conference{ EndresANG2012, title = {Explicit coding in the brain: data-driven semantic analysis of human fMRI BOLD responses with Formal Concept Analysis}, journal = {Perception}, year = {2012}, month = {9}, volume = {41}, number = {ECVP Abstract Supplement}, pages = {67}, abstract = {We investigated whether semantic information about object categories can be obtained from human fMRI BOLD responses with Formal Concept Analysis (FCA), an order-theoretic approach for the analysis of semantic information, such as specialization hierarchies and parts-based codes. Unlike other analysis methods (eg hierarchical clustering), FCA does not impose inappropriate structure on the data. FCA is a mathematical formulation of the explicit coding hypothesis (Foldiak, 2009 Current Biology19R904-R906). A human subject was scanned viewing 72 gray-scale pictures of animate and inanimate objects in a target detection task. To apply FCA, we employ a hierarchical Bayesian classifier, which maps fMRI responses onto binary attributes, and these onto object labels. The connectivity matrix between attributes and labels is the formal context for FCA. FCA revealed a clear dissociation between animate and inanimate objects in a high-level visual area (inferior temporal cortex, IT), with the inanimate category including plants. The inanimate category was subdivided into plants and non-plants when we increased the number of attributes extracted from the fMRI responses. FCA also displayed organizational differences between the IT and the primary visual cortex, V1. We show that familiarity and similarity ratings are strongly correlated with the attributes computed from the fMRI signal.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v120406}, event_name = {35th European Conference on Visual Perception}, event_place = {Alghero, Italy}, state = {published}, author = {Endres D, Adam R{ruthi}{Research Group Cognitive Neuroimaging}, Noppeney U{unoppe}{Research Group Cognitive Neuroimaging} and Giese M{giese}} } @Conference{ SchultzFdBK2012, title = {How are facial expressions represented in the human brain?}, journal = {Perception}, year = {2012}, month = {9}, volume = {41}, number = {ECVP Abstract Supplement}, pages = {38}, abstract = {The dynamic facial expressions that we encounter every day can carry a myriad of social signals. What are the neural mechanisms allowing us to decode these signals? A useful basis for this decoding could be representations in which the facial expressions are set in relation to each other. Here, we compared the behavioral and neural representations of 12 facial expressions presented as pictures and videos. Behavioral representations of these expressions were computed based on the results of a semantic differential task. Neural representations of these expressions were obtained by multivariate pattern analysis of functional magnetic imaging data. The two kinds of representations were compared using correlations. For expression videos, the results show a significant correlation between the behavioral and neural representations in the superior temporal sulcus (STS), the fusiform face area, the occipital face area and the amygdala, all in the left hemisphere. For expression pictures, a significant correlation was found only in the left STS. These results suggest that of all tested regions, the left STS contains the neural representation of facial expressions that is closest to their behavioral representation. This confirms the predominant role of STS in coding changeable aspects of faces, which includes expressions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v120194}, event_name = {35th European Conference on Visual Perception}, event_place = {Alghero, Italy}, state = {published}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action}, Fernandez Cruz AL{anafer}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Kaulard K{kascot}{Department Human Perception, Cognition and Action}} } @Conference{ CurioGBd2012, title = {Motor-visual effects in the recognition of dynamic facial expressions}, journal = {Perception}, year = {2012}, month = {9}, volume = {41}, number = {ECVP Abstract Supplement}, pages = {44}, abstract = {Current theories on action understanding suggest a cross-talk between the motor and the visual system during the recognition of other persons'actions. We examined the effect of the motor execution on the visual recognition of dynamic emotional facial expressions using an adaptation paradigm. Previous research on facial expression adaptation has shown that the prolonged visual exposure to a static facial expression biases the percept of an ambiguous static facial expression away from the adapted facial expression. We used a dynamic 3D computational face model (Curio et al, 2010, MIT Press, 47-65) to examine motor-visual interactions in the recognition of happy and fearful facial expressions. During the adaptation phase participants (1) looked for a prolonged amount of time at a facial expression (visual adaptation); (2) executed repeatedly a facial expression (motor adaptation); (3) imagined the emotion corresponding to a facial expression (imagine adaptor). In the test phase participants always had to judge an ambiguous facial expression as either happy or fearful. We found an adaptation effect in the visual adaptation condition, and the reversed effect (priming effect) in the motor and imagine condition. Inconsistent with simple forms of motor resonance, this shows antagonistic influences of visual and motor adaptation.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v120450}, event_name = {35th European Conference on Visual Perception}, event_place = {Alghero, Italy}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}, Giese M{giese}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2012_6, title = {Passive and Decentralized Shared Control of Multi-Robot Systems}, year = {2012}, month = {7}, day = {18}, event_name = {Australian National University}, event_place = {Canberra, Australia}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ KimESBW2012, title = {Mapping the other-race-effect in face recognition using a three-experiment test battery}, year = {2012}, month = {7}, day = {15}, volume = {8}, pages = {65}, abstract = {The fact that people are better at recognizing faces of their own race than others is called the other-race-effect (ORE). Most studies use only a single test to map and determine the characteristics of the ORE, however. Here, we investigated how two groups of fifteen age-matched Korean and German participants recognize Asian and Caucasian faces with three experiments as part of testing a new battery for characterizing face-processing performance. Participants first underwent the standard Cambridge face memory test in which they had to learn Caucasian target faces at varying noise levels which then were to be recognized in a forced-choice task. In this task, German participants performed significantly better than Koreans (83% versus 72%). The second experiment used a standard old-new recognition task with 20 Caucasian and 20 Asian faces (courtesy of the tarrlab@CMU). Here, Koreans were better with Asian faces (d’-difference=1.23) whereas Germans only showed a tendency towards an ORE (d’-difference=0.44). In the third experiment, participants had to rate the similarity of Caucasian face pairs which varied parametrically along featural and configural dimensions using the morphable faces from the MPI face-database. Here, we found that Korean participants were significantly less sensitive to featural changes than German participants. In conclusion, we were able to demonstrate an ORE for most of our experimental conditions. Interestingly, data from the third experiment suggests that the ORE may be due more to lessened sensitivity to featural than to configural processing for other-race faces. Future studies will extend this new test battery to prosopagnosics. Acknowledgement: This research was supported by the World Class University (WCU) program through the National Research Foundation of Korea funded by the Ministry of Education, Science, and Technology (R31-1008-000-10008-0).}, web_url = {http://apcv2012.com/}, event_name = {8th Asia-Pacific Conference on Vision (APCV 2012)}, event_place = {Incheon, South Korea}, state = {published}, author = {Kim BR, Esins J{esins}{Department Human Perception, Cognition and Action}, Schultz J{johannes}{Department Human Perception, Cognition and Action}, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2012_7, title = {Multi-UAV Bilateral Shared Control and Decentralization}, year = {2012}, month = {7}, day = {5}, file_url = {fileadmin/user_upload/files/publications/2012/2012-7-5_AIRobots_Summer_School_PaoloRobuffoGiordano_.pdf}, web_url = {http://www.roboticsschool.ethz.ch/airobots}, event_name = {Summer School Airobots: Aerial Service Robotics, Eidgenössische Technische Hochschule}, event_place = {Zürich, Switzerland}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ BarnettCowan2012, title = {Perceived timing of vestibular stimulation}, journal = {Seeing and Perceiving}, year = {2012}, month = {6}, day = {22}, volume = {25}, number = {0}, pages = {206}, abstract = {Multisensory stimuli originating from the same event can be perceived asynchronously due to differential physical and neural delays. The transduction of and physiological responses to vestibular stimulation are extremely fast, suggesting that other stimuli need to be presented prior to vestibular stimulation in order to be perceived as simultaneous. There is, however, a recent and growing body of evidence which indicates that the perceived onset of vestibular stimulation is slow compared to the other senses, such that vestibular stimuli need to be presented prior to other sensory stimuli in order to be perceived synchronously. Following a review of this literature I will argue that this perceived latency of vestibular stimulation likely reflects the fact that vestibular stimulation is most often associated with sensory events that occur following head movement, that the vestibular system rarely works alone, and that the brain prioritizes physiological response to vestibular stimulation over perceptual awareness of stimulation onset.}, web_url = {http://booksandjournals.brillonline.com/content/10.1163/187847612x648350}, event_name = {13th International Multisensory Research Forum (IMRF 2012)}, event_place = {Oxford, UK}, state = {published}, DOI = {10.1163/187847612X648350}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}} } @Conference{ SoykaBRB2012, title = {Temporal processing of self-motion: Translations are processed slower than rotations}, journal = {Seeing and Perceiving}, year = {2012}, month = {6}, day = {22}, volume = {25}, number = {0}, pages = {207-208}, abstract = {Reaction times (RTs) to purely inertial self-motion stimuli have only infrequently been studied, and comparisons of RTs for translations and rotations, to our knowledge, are nonexistent. We recently proposed a model [1] which describes direction discrimination thresholds for rotational and translational motions based on the dynamics of the vestibular sensory organs (otoliths and semi-circular canals). This model also predicts differences in RTs for different motion profiles (e.g., trapezoidal versus triangular acceleration profiles or varying profile durations). In order to assess these predictions we measured RTs in 20 participants for 8 supra-threshold motion profiles (4 translations, 4 rotations). A two-alternative forced-choice task, discriminating leftward from rightward motions, was used and 30 correct responses per condition were evaluated. The results agree with predictions for RT differences between motion profiles as derived from previously identified model parameters from threshold measurements. To describe absolute RT, a constant is added to the predictions representing both the discrimination process, and the time needed to press the response button. This constant is approximately 160ms shorter for rotations, thus indicating that additional processing time is required for translational motion. As this additional latency cannot be explained by our model based on the dynamics of the sensory organs, we speculate that it originates at a later stage, e.g. during tilt-translation disambiguation. Varying processing latencies for different self-motion stimuli (either translations or rotations) which our model can account for must be considered when assessing the perceived timing of vestibular stimulation in comparison with other senses [2,3].}, web_url = {http://booksandjournals.brillonline.com/content/10.1163/187847612x648369}, event_name = {13th International Multisensory Research Forum (IMRF 2012)}, event_place = {Oxford, UK}, state = {published}, DOI = {10.1163/187847612X648369}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Barnett Cowan M{mbc}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ DobrickiMB2012_2, title = {The structure of self-experience during visuo-tactile stimulation of a virtual and the physical body}, journal = {Seeing and Perceiving}, year = {2012}, month = {6}, day = {22}, volume = {25}, number = {0}, pages = {214}, abstract = {The simultaneous visuo-tactile stimulation of an individual’s body and a virtual body (avatar) is an experimental method used to investigate the mechanisms of self-experience. Studies incorporating this method found that it elicits the experience of bodily ownership over the avatar. Moreover, as part of our own research we found that it has also an effect on the experience of agency, spatial presence, as well as on the perception of self-motion, and thus on self-localization. However, it has so far not been investigated whether these effects represent distinct categories within conscious experience. We stroked the back of 21 male participants for three minutes while they watched an avatar getting synchronously stroked within a virtual city in a head-mounted display setup. Subsequently, we assessed their avatar and their spatial presence experience with 23 questionnaire items. The analysis of the responses to all items by means of nonmetric multidimensional scaling resulted in a two-dimensional map (stress=0.151) on which three distinct categories of items could be identified: a cluster (Cronbach’s alpha=.89) consisting of all presence items, a cluster (Cronbach’s alpha=.88) consisting of agency-related items, and a cluster (Cronbach’s alpha=.93) consisting of items related to body ownership as well as self-localization. The reason that spatial presence formed a distinct category could be that body ownership, self-localization and agency are not reported in relation to space. Body ownership and self-localization belonged to the same category which we named identification phenomena. Hence, we propose the following three higher-order categories of self-experience: identification, agency, and spatial presence.}, web_url = {http://booksandjournals.brillonline.com/content/10.1163/187847612x648413}, event_name = {13th International Multisensory Research Forum (IMRF 2012)}, event_place = {Oxford, UK}, state = {published}, DOI = {10.1163/187847612X648413}, author = {Dobricki M{mdobricki}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ AdamN2012, title = {Processing of audiovisual phonological incongruency depends on awareness}, journal = {Seeing and Perceiving}, year = {2012}, month = {6}, day = {21}, volume = {25}, number = {0}, pages = {168}, abstract = {Capacity limitations of attentional resources allow only a fraction of sensory inputs to enter our awareness. Most prominently, in the attentional blink, the observer fails to detect the second of two rapidly successive targets that are presented in a sequence of distractor items. This study investigated whether phonological (in)congruency between visual target letters and spoken letters is modulated by subjects’ awareness. In a visual attentional blink paradigm, subjects were presented with two visual targets (buildings and capital Latin letters, respectively) in a sequence of rapidly presented distractor items. A beep was presented always with T1. We manipulated the presence/absence and phonological congruency of the spoken letter that was presented concurrently with T2. Subjects reported the identity of T1 and T2 and reported the visibility of T2. Behaviorally, subjects correctly identified T2 when it was reported to be either visible or unsure, while performances were below chance level when T2 was reported to be invisible. At the neural level, the anterior cingulate was activated for invisible>unsure>visible T2. In contrast, visible relative to invisible trials increased activation in bilateral cerebellum, pre/post-central gyri extending into parietal sulci and bilateral inferior occipital gyri. Incongruency effects were observed in the left inferior frontal gyrus, caudate nucleus and insula only for visible stimuli. In conclusion, phonological incongruency is processed differently when subjects are aware of the visual stimulus. This indicates that multisensory integration is not automatic but depends on subjects’ cognitive state.}, web_url = {http://booksandjournals.brillonline.com/content/10.1163/187847612x647982}, event_name = {13th International Multisensory Research Forum (IMRF 2012)}, event_place = {Oxford, UK}, state = {published}, DOI = {10.1163/187847612X647982}, author = {Adam R{ruthi}{Research Group Cognitive Neuroimaging} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Conference{ NoppeneyASMLWOLC2012, title = {Different classes of audiovisual correspondences are processed at distinct levels of the cortical hierarchy}, journal = {Seeing and Perceiving}, year = {2012}, month = {6}, day = {20}, volume = {25}, number = {0}, pages = {69}, abstract = {The brain should integrate sensory inputs only when they emanate from a common source and segregate those from different sources. Sensory correspondences are important cues informing the brain whether two sensory inputs are generated by a common event and should hence be integrated. Most prominently, sensory inputs should co-occur in time and space. More complex audiovisual stimuli may also be congruent in terms of semantics (e.g., objects and source sounds) or phonology (e.g., spoken and written words; linked via common linguistic labels). Surprisingly, metaphoric relations (e.g., pitch and height) have also been shown to influence audiovisual integration. The neural mechanisms that mediate these metaphoric congruency effects are only poorly understood. They may be mediated via (i) natural multisensory binding, (ii) common linguistic labels or (iii) semantics. In this talk, we will present a series of studies that investigate whether these different types of audiovisual correspondences are processed by distinct neural systems. Further, we investigate how those systems are employed by metaphoric audiovisual correspondences. Our results demonstrate that different classes of audiovisual correspondences influence multisensory integration at distinct levels of the cortical hierarchy. Spatiotemporal incongruency is detected already at the primary cortical level. Natural (e.g., motion direction) and phonological incongruency influences MSI in areas involved in motion or phonological processing. Critically, metaphoric interactions emerge in neural systems that are shared with natural and semantic incongruency. This activation pattern may reflect the ambivalent nature of metaphoric audiovisual interactions relying on both natural and semantic correspondences.}, web_url = {http://booksandjournals.brillonline.com/content/10.1163/187847612x646901}, event_name = {13th International Multisensory Research Forum (IMRF 2012)}, event_place = {Oxford, UK}, state = {published}, DOI = {10.1163/187847612X646901}, author = {Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}, Adam R{ruthi}{Research Group Cognitive Neuroimaging}, Sadaghiani S{ssadaghi}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging}, Maier JX{jmaier}{Department Human Perception, Cognition and Action}, Lee HL{hweeling}{Research Group Cognitive Neuroimaging}, Werner S{sebastianwerner}{Research Group Cognitive Neuroimaging}, Ostwald D{ostwaldd}{Department Human Perception, Cognition and Action}, Lewis R{rklewis}{Research Group Cognitive Neuroimaging} and Conrad V{conrad}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging}} } @Conference{ ConradVN2012_2, title = {Interactions between apparent motion rivalry in vision and touch}, journal = {Seeing and Perceiving}, year = {2012}, month = {6}, day = {19}, volume = {25}, number = {0}, pages = {26-27}, abstract = {Introduction In multistable perception, the brain alternates between several perceptual explanations of ambiguous sensory signals. Recent studies have demonstrated crossmodal interactions between ambiguous and unambiguous signals. However it is currently unknown whether multiple bistable processes can interact across the senses. [1, 2] Using the apparent motion quartet in vision and touch, this study investigated whether bistable perceptual processes for vision and touch are independent or influence each other when powerful cues of congruency are provided to facilitate visuotactile integration. [3] Methods When two visual flashes and/or tactile vibration pulses are presented alternately along the two diagonals of the rectangle, subjects’ percept vacillates between vertical and horizontal apparent motion in the visual and/or tactile modalities [4]. Observers were presented with unisensory (visual/tactile), visuotactile spatially congruent and incongruent apparent motion quartets and reported their visual or tactile percepts. Results Congruent stimulation induced pronounced visuotactile interactions as indicated by increased dominance times and %-bias for the percept already dominant under unisensory stimulation. Yet, the temporal dynamics did not converge for congruent stimulation. It depended also on subjects’ attentional focus and was generally slower for tactile than visual reports. Conclusion Our results support Bayesian approaches to perceptual inference, where the probability of a perceptual interpretation is determined by combining a modality-specific prior with incoming visual and/or tactile evidence. Under congruent stimulation, joint evidence from both senses decelerates the rivalry dynamics by stabilizing the more likely perceptual interpretation. Importantly, the perceptual stabilization was specific to spatiotemporally congruent visuotactile stimulation indicating multisensory rather than cognitive bias mechanisms.}, web_url = {http://booksandjournals.brillonline.com/content/10.1163/187847612x646497}, event_name = {13th International Multisensory Research Forum (IMRF 2012)}, event_place = {Oxford, UK}, state = {published}, DOI = {10.1163/187847612X646497}, author = {Conrad V{conrad}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}{Research Group Cognitive Neuroimaging}, Vitello MP{vitello}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Conference{ Bieg2012, title = {Saccadic and pursuit eye movements during coordinated behaviors}, year = {2012}, month = {6}, day = {19}, abstract = {Gaze control is largely determined by an observer's behavioral goals. In this respect, eye movements are one of many coordinated actions to achieve these goals. In this presentation I will discuss experiments which studied the properties of saccadic and pursuit eye movements in concerted behaviors, for example in steering a vehicle. In this respect, I will consider an aspect of gaze control which has largely been neglected by previous research: the consequence of eye movements for visual perception and the associated behavioral consequence in terms of the value of the obtained additional information}, web_url = {http://webu2.upmf-grenoble.fr/LPNC/seminaire_2012-06-19_13h-14h}, event_name = {Laboratoire de Psychologie et Neurocognition (LPNC), Université Pierre Mendès-France}, event_place = {Grenoble, France}, state = {published}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2012_3, title = {Motion Control and Haptic Intervention with Multiple Mobile Robots}, year = {2012}, month = {6}, day = {14}, abstract = {This talk will give an overview of some theoretical and experimental results in the multi-robot field, with a special regard to the multi-UAV case. It is commonly acknowledged that the major strengths of a multi-robot system are both the resilience to single point failures and the possibility of parallelizing the execution of a given task. These properties can be fully exploited in coverage-like tasks, e.g., exploration, pursuit-evasion (a.k.a. "clearing"), and periodical monitoring (a.k.a. "patrolling"). These tasks, in turn, contain several control and estimation subproblems. In fact, a coverage-like task often requires to keep a certain optimal arrangement which can be achieved by using an appropriate formation controller. Among the major challenges in this case there are both the decentralization of the controller and the use of cheap and lightweight sensors, like cameras. Moreover in order to allow a proper fusion of the information gained by every single robot, it is fundamental to share a common reference frame, i.e., to continuously perform a mutual localization among the robots. A particularly challenging situation in this case is when the robot-detector, which is used for estimating the mutual pose, is anonymous, i.e., it does not retrieve the identity of the detected robot. This represents a usual situation in realistic scenarios when many robots are involved and cameras are used as exteroceptive sensors. Furthermore, whenever some collaborative task is performed, e.g., formation control or navigation in cluttered environment, it is also of chief importance to keep the connectivity of the group while still allowing for a flexible behavior of the robots, i.e., a time-varying topology. Finally, the presence of one or more human co-operators may be extremely useful for the multi-robot system, especially whenever the task becomes particularly challenging and requires complex, cognitive capabilities, e.g., in search and rescue operation. A relevant problem in this shared control case is how to balance the robot autonomy with the human assistance. It has also been proven that the presence of a bilateral (haptic) connection between the human and the machine increases the human situational awareness and improves the quality of the human-robot cooperation. On the other hand, the presence of a force feedback makes the control of the whole system more challenging, e.g., in case long-distances between the co-operator and the robotic group.}, web_url = {http://www.eventi.unimore.it/index.php/component/jcalpro/view/5311}, event_name = {Department of Science and Methods for Engineering: University of Modena and Reggio Emilia}, event_place = {Reggio Emilia, Italy}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2012_8, title = {Passive and Decentralized Shared Control of Multi-Robot Systems}, year = {2012}, month = {6}, day = {14}, event_name = {Università di Modena e Reggio Emilia}, event_place = {Reggio Emilia, Italy}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ VolkovaM2012, title = {ePETaLS: Online Annotation Tool for Emotional Text Labelling}, year = {2012}, month = {6}, day = {3}, abstract = {Text annotation is one of the most popular methods of linguistic data collection. The quality of the resulting corpus is one of the major concerns for the researchers, especially when the annotation process is performed by participants who have not received any speci c task-related training. One important factor that can help to ensure high resulting quality is a user-friendly annotation environment. In this talk we present a new annotation system ePETaLS [1] that can help researchers to collect texts annotated for various emotions. Pre-formatted texts can be uploaded onto the system and their annotation can be assigned to a participant, whose task is to mark each phrase in the text with a speci c emotion or leave it neutral. For each phrase, the annotator is also asked to assign the emotional forse and mark the word on which the emotional emphasis falls. Before submission the annotation is checked and the user is informed of any missing values. This step help to ensure higher quality of the resulting texts. The time spent on each annotation is also logged which helps to detect outliers who spend extremely little or too much time on their annotation tasks. The resulting annotation is saved in the XML format and is ready for data extraction. Before an annotation procedure can begin, each text is automatically split into small annotation units. These units correspond to short phrases that people would usually pronounce without pausing when they read the text out loud. Each sentence in the text can contain one and more of such units, a typical unit length is three to seven word tokens. This component of ePETaLS is based on supervised machine learning system TiMBL [2] and uses WebLicht [3] for linguistic data extraction, e.g. lemmas, POS, dependency relation, etc. The machine learning algorithm uses a small corpus of texts that were split into phrases by nave participants. The annotation system is at present used for collecting a corpus of fairy tales in English written down by Andrew Lang [4]. Each text is annotated for ten to thirteen emotions. The nal goal of the project is to create an automatic sentiment analysis system for emotional virtual character animation.}, file_url = {fileadmin/user_upload/files/publications/2012/TACOS-2012-Volkova.pdf}, web_url = {http://tacos.uni-trier.de/?s=timetable}, event_name = {22. Tagung der Computerlinguistik-Studierenden (TaCoS 2012)}, event_place = {Trier, Germany}, state = {published}, author = {Volkova E{evolk}{Department Human Perception, Cognition and Action} and Mstislavski A{amstlvsk}{Department Human Perception, Cognition and Action}} } @Conference{ SoykaBRB2012_2, title = {Translations are processed slower than rotations: reaction times for self-motion stimuli predicted by vestibular organ dynamics}, year = {2012}, month = {6}, volume = {27}, number = {0151}, abstract = {Reaction times (RTs) to purely inertial self-motion stimuli have only infrequently been studied, and comparisons of RTs for translations and rotations, to our knowledge, are nonexistent. We recently proposed a model [1] which describes direction discrimination thresholds for rotational and translational motions based on the dynamics of the vestibular sensory organs. This model also predicts differences in RTs for different motion profiles (e.g., trapezoidal versus triangular acceleration profiles or varying profile durations). The model calculates a signal akin to the change in firing rate in response to a self-motion stimulus. In order to correctly perceive the direction of motion the intrinsic noise level of the firing rate has to be overcome. Based on previously identified model parameters from perceptual thresholds, differences in RTs between varying motion profiles can be predicted by comparing the times at which the firing rate overcomes the noise level. To assess these predictions we measured RTs in 20 participants for 8 supra-threshold motion profiles (4 translations, 4 rotations). A two-alternative forced-choice task, discriminating leftward from rightward motions, was used and 30 correct responses per condition were evaluated. The results are in agreement with predictions for RT differences between motion profiles. In order to describe absolute RT, a constant is added to the predictions representing both the discrimination process, and the time needed to press the response button. This constant is calculated as the mean difference between measurements and predictions. It is approximately 160ms shorter for rotations, thus indicating that additional processing time is required for translational motion. As this additional latency cannot be explained by our model based on the dynamics of the sensory organs, we speculate that it originates at a later stage, e.g. during tilt-translation disambiguation.}, web_url = {http://www.barany2012.se/}, event_name = {27th Bárány Society Meeting}, event_place = {Uppsala, Sweden}, state = {published}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2012_4, title = {The Cybernetic Approach to Perception and Action}, year = {2012}, month = {5}, day = {23}, event_name = {CITEC Colloquium "Vision Science" - Universität Bielefeld}, event_place = {Bielefeld, Germany}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2012, title = {Multi-robot algorithms for coverage, localization, and control, with decentralized maintenance of global connectivity and haptic interaction}, year = {2012}, month = {5}, day = {22}, event_name = {Department of Computer Science, University of Minnesota}, event_place = {Minneapolis, MN, USA}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2012_2, title = {Modeling, Control, and Haptic Steering of Multi-robot Formations}, year = {2012}, month = {5}, day = {14}, abstract = {This talk will overview some theoretical and experimental results in the modeling, control and haptic steering of multi-robot formations, with a special regard to the multi-UAV case. It is commonly acknowledged that the major strengths of a multi-robot system are both the resilience to single point failures and the possibility of parallelizing the execution of a given task. These properties can be fully exploited in coverage-like tasks, e.g., exploration, pursuit-evasion (a.k.a. "clearing"), and periodical monitoring (a.k.a. "patrolling"). These tasks, in turn, contain several control subproblems. All these tasks often requires to keep a certain optimal arrangement which can be achieved by using an appropriate formation controller. Among the major challenges in this case there are both the decentralization of the controller and the use of cheap and lightweight sensors, like cameras. In addition to that, the presence of one or more human co-operators may result extremely useful for the multi-robot system, especially whenever the task becomes particularly challenging and requires complex, cognitive capabilities, e.g., in search and rescue operations. A relevant problem in this shared control case is how to balance the robot autonomy with the human assistance. It has also been proven that the presence of a bilateral (haptic) connection between the human and the machine increases the human situational awareness and improves the quality of the human-robot cooperation. On the other hand, the presence of a force feedback makes the control of the whole system more challenging, e.g., in case long-distances between the co-operator and the robotic group.}, web_url = {http://www.arscontrol.org/events/61-icra2012htmr}, event_name = {ICRA 2012 - Workshop on Haptic Teleoperation of Mobile Robots: Theory, Applications and Perspectives}, event_place = {St. Paul, MN, USA}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ Son2012, title = {Psychophysical Evaluation of Visual and Haptic Feedback in Teleoperation of Multiple Mobile Robots}, year = {2012}, month = {5}, day = {14}, abstract = {For teleoperation of (multiple) mobile robot(s), a better situational awareness of remote environments is crucial for good performance. Visual and haptic feedback are the most common ways to perceive the environments accurately using a vision system and a haptic device, respectively. In this talk, I will present benefits and effects of visual and haptic feedback on performance (especially, from human perspective) in teleoperation of multiple mobile robots (e.g., unmanned aerial vehicles (UAVs)). In details, the following three issues will be described with results by several psychophysical studies in the field of bilateral teleoperation of multiple mobile robots: 1) the contribution of force feedback to human performance; 2) the design and evaluation of haptic cueing to increase human operator's performance; and 3) the effect of visual feedback on human's situational awareness in outdoor environment.}, web_url = {http://www.arscontrol.org/events/61-icra2012htmr}, event_name = {ICRA 2012 - Workshop on Haptic Teleoperation of Mobile Robots: Theory, Applications and Perspectives}, event_place = {St. Paul, MN, USA}, state = {published}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2012, title = {Shared Control of Multi-Robot Systems: Passivity, Decentralization, and Connectivity Maintenance}, year = {2012}, month = {5}, day = {14}, abstract = {This talk will cover some recent theoretical and experimental results in the new topic of Bilateral Shared Control of Multiple Mobile Robots, with a special attention to the case of Unmanned Aerial Vehicles (UAVs). In this non-conventional teleoperation field, a human operator partially controls the behavior of a semi-autonomous group of mobile robots by means of one or more haptic interfaces, and receives back a force cue informative of the swarm tracking performance and of additional properties of the surrounding environment (e.g., presence of obstacles or loss of group connectivity). This kind of systems is designed in order to enhance the telepresence of the operator and the quality of the human robot interaction, especially when applied to practical scenarios, like search and rescue, surveillance, exploration and mapping. The talk will first present an overview of the nature and kind of problems addressed within this research such as, e.g., how to design a stable bilateral interconnection between the user and a group of flying robots bound to maintain connectivity of the underlying interaction graph, but otherwise free to shape their formation because of additional constraints or sub-tasks. We will present theoretical and experimental results obtained on a group of quadrotor UAVs, and then discuss future research directions.}, web_url = {http://www.arscontrol.org/events/61-icra2012htmr}, event_name = {ICRA 2012 - Workshop on Haptic Teleoperation of Mobile Robots: Theory, Applications and Perspectives}, event_place = {St. Paul, MN, USA}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2012_3, title = {Shared control of remote multi-robot aerial systems: state-of-the-art and future perspectives}, year = {2012}, month = {5}, day = {10}, event_name = {"UAVs in perspective" Symposium, Università di Bologna}, event_place = {Bologna, Italy}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2012_2, title = {Passive and Decentralized Shared Control of Multi-Robot Systems}, year = {2012}, month = {5}, event_name = {Boston University}, event_place = {Boston, MA, USA}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2012_2, title = {myCopter: Enabling Technologies for Personal Aerial Transportation Systems}, year = {2012}, month = {3}, day = {7}, abstract = {The helicopter is man’s best friend. Utilized all over the world for life saving missions, the helicopter is evolving rapidly to be able to integrate itself within the city limits. The Max Plank Institute of Technology is leading a research project funded by the European Union to identify future technologies allowing the use of helicopters within the cities. He shares the main goals of this research project. The audience will be able to interact with the various helicopter experts on all aspects of the use of rotary wing crafts today and tomorrow.}, web_url = {http://www.adairexpo.com/conference.php?lang=en}, event_name = {Abu Dhabi Air Expo: Helicopter Conference}, event_place = {Abu Dhabi, United Arab Emirates}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2012, title = {Flying Robots and Flying Cars}, year = {2012}, month = {3}, day = {1}, web_url = {http://expertdays.schunk.com/index.php?id=61}, event_name = {5th Schunk International Expertdays: Service Robotics}, event_place = {Hausen, Germany}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2012_4, title = {Shared Control of Remote Multi-Robot Systems: State-of-the-art and Future Perspectives}, year = {2012}, month = {3}, event_name = {Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA/INRIA)}, event_place = {Rennes, France}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2012_5, title = {Shared Control of Remote Multi-Robot Systems: State-of-the-art and Future Perspectives}, year = {2012}, month = {2}, event_name = {University of Würzburg - Institute of Computer Science}, event_place = {Würzburg, Germany}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Book{ Armann2011, title = {Faces in the Brain: a Behavioral, Eye-tracking and High-level Adaptation Approach to Human Face Perception}, year = {2011}, pages = {167}, web_url = {http://www.logos-verlag.de/cgi-bin/engbuchmid?isbn=2900&lng=deu&id=}, publisher = {Logos-Verlag}, address = {Berlin, Germany}, series = {MPI Series in Biological Cybernetics ; 29}, state = {published}, ISBN = {978-3-8325-2900-0}, author = {Armann R{armann}{Department Human Perception, Cognition and Action}} } @Book{ Gaissert2011, title = {Perceiving Complex Objects: A Comparison of the Visual and the Haptic Modalities}, year = {2011}, pages = {204}, abstract = {Das wichtigste Werkzeug des Menschen sind seine Hände. Obwohl dieses Sprichwort schon sehr alt ist, ist nur wenig darüber bekannt, wie und was der Mensch wahrnimmt, wenn er Objekte in die Hand nimmt und betastet. Wie wird die ertastete Form eines Objektes im Gehirn abgespeichert? Ist die haptische Repräsentation ähnlich zu der, der visuellen Wahrnehmung? Entsteht sogar eine multisensorische, und somit gemeinsame, Repräsentation? Diese fundamentalen Fragen bilden den Hintergrund der vorliegenden Dissertation. Die hier dargestellten Experimente zeigen, dass der Mensch sehr ähnliche perzeptuelle Räume generiert, wenn komplexe Formen eines parametrisch definierten Objektraumes visuell oder haptisch exploriert werden. Um dies zu zeigen, wurde zuerst ein dreidimensionaler Objektraum muschelähnlicher Objekte generiert, welche in drei Formparametern variieren. Versuchspersonen wurden in den visuellen Versuchen Fotos oder virtuelle Rekonstruktionen der Objekte gezeigt, während in den haptischen Versuchen 3D Plastikmodelle der Objekte, generiert mit einem 3D Drucker, mit verbundenen Augen betastet wurden. In einer ersten Reihe von Experimenten bewerteten die Versuchspersonen die Ähnlichkeit zweier, nacheinander gezeigter, Objekte. Mit diesen Ähnlichkeitsbewertungen und mit Hilfe des Verfahrens der multidimensionalen Skalierung wurden die perzeptuellen Räume beider Modalitäten visualisiert. Überraschenderweise konnten die Versuchspersonen die Topologie des Objektraumes korrekt nachbilden, unabhängig davon, ob sie die Objekte gesehen oder betastet hatten. Weiterhin zeigten die Ergebnisse, dass der visuelle und der haptische perzeptuelle Raum fast identisch waren. Als nächstes wurden drei Kategorisierungsexperimente durchgeführt. Obwohl Kategorisierung allein durch den Tastsinn eher eine ungewöhnliche Aufgabe ist, konnte sie genauso gut gelöst werden, wie wenn die Versuchspersonen die Objekte sehen konnten. Anschließend wurden die perzeptuellen Räume beider Modalitäten mit den Ergebnissen der Kategorisierungsexperimente verglichen. Für alle Kategorisierungsexperimente und für beide Modalitäten war die wahrgenommene Ähnlichkeit zwischen Objekten einer Kategorie höher, als die Ähnlichkeit zweier Objekte aus unterschiedlichen Kategorien. Das heißt, dass, sowohl visuell als auch haptisch, Objekte in einer Kategorie zusammengruppiert wurden, die als sehr ähnlich wahrgenommen wurden. Um zu untersuchen, inwieweit die auf den computergenerierten Objekten basierenden Ergebnisse auf natürliche Objekte übertragbar sind, wurde eine Sammlung von Muscheln und Salzwasserschnecken erstellt. Mit diesen wurden, wie oben beschrieben, Ähnlichkeitsbewertungen durchgeführt und mittels multidimensionaler Skalierung die perzeptuellen Räume visualisiert. Wiederum waren der visuelle und der haptische perzeptuelle Raum fast identisch. Interessanterweise konnte man in beiden Räumen eine Gruppenbildung erkennen, weshalb auch hier drei Kategorisierungsexperimente durchgeführt wurden. Obwohl die Muscheln in einer Vielzahl an Objektmerkmalen variierten, z.B. Form, Farbe, Muster etc., konnten die Versuchspersonen diese Aufgabe ohne Mühe lösen, auch wenn sie die Objekte nur betasten durften. Zusätzlich konnte die Gruppenbildung, die schon in den perzeptuellen Räumen erkennbar war, die Kategorisierungsergebnisse richtig vorhersagen. Zusammengenommen weisen diese Ergebnisse darauf hin, dass die visuelle und die haptische Repräsentation von Objekten sehr eng miteinander verknüpft sein müssen. Zusätzlich liefern die Experimente Hinweise darauf, dass die gleichen Prozesse genutzt werden, wenn Ähnlichkeiten zwischen Objekten wahrgenommen werden, oder Objekte kategorisiert werden, egal ob die Objekte visuell oder haptisch exploriert werden.}, web_url = {http://www.logos-verlag.de/cgi-bin/engbuchmid?isbn=2794&lng=eng&id=}, publisher = {Logos-Verlag}, address = {Berlin, Germany}, series = {MPI Series in Biological Cybernetics ; 26}, state = {published}, ISBN = {978-3-8325-2794-5}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action}} } @Book{ LL2011, title = {Recognizing Objects from Dynamic Visual Experiences}, year = {2011}, pages = {162}, web_url = {http://www.logos-verlag.de/cgi-bin/engbuchmid?isbn=2842&lng=deu&id=}, publisher = {Logos-Verlag}, address = {Berlin, Germany}, series = {MPI Series in Biological Cybernetics ; 28}, state = {published}, ISBN = {978-3-8325-2842-3}, author = {LL Chuang{chuang}{Department Human Perception, Cognition and Action}} } @Book{ Engel2011_2, title = {Shape-Centered Representations: From Features to Applications}, year = {2011}, pages = {173}, abstract = {Computer vision aims to teach machines and algorithms to 'see' with the ultimate goal of creating 'intelligent' applications and devices that can provide assistance to humans in a wide array of scenarios. This thesis presents an investigation of computer vision on three layers: low-level features, mid-level representations and high-level applications. Each of the layers depends on the previous ones while also generating constraints and requirements for them. At the application layer human-machine interfaces come into play and link the human perception to computer vision. By studying all layers we can gain a much deeper insight into the interplay of different methods, than by examining an isolated problem. Furthermore, we are able to factor constraints imposed by different layers and the users into the design of the algorithms, instead of optimizing a single method based purely on algorithmic performance measures. After a brief introduction in Chapter 1, Chapter 2 addresses the feature layer and describes our novel shape-centered interest points that play a vital role throughout this thesis. These interest points are formed at location of high local symmetry as opposed to corner interest points which occur along the outline of shapes. Experiments show that they are very robust with respect to common natural image transformations, such as scaling, rotation and the introduction of noise and clutter. Based on these features Chapter 3 presents two strategies to build robust mid-level image representations. First, a novel feature grouping method is introduced. The scheme offers a powerful way to combine the advantages of shape-centered interest points, namely robustness and a tight connection to a unique shape, and corner-based interest points, namely strong descriptors. Furthermore, Chapter 3 introduces a novel set of medial feature superpixels, that represent a feed-forward way to divide the image into small, visually-homogeneous regions offering a compact and efficient mid-level representation of the image information. Finally, Chapter 4 bridges the gap between computer vision and the human observer by introducing three applications that employ the shape-centered representations from the two previous Chapters. First a multi-class scene labeling scheme is presented that produces dense annotations of images, combining a local prediction step with a global optimization scheme. Then, Section 4.2 introduces a novel image retrieval tool that operates on highlevel semantic information. Such semantic annotations could be generated by automatic annotation schemes as the one described in the previous Section. Finally, the novel idea of predicting the detectability of a pedestrian in a driver assistance context is put forward and investigated. The different modules of this thesis are tightly connected and inter-dependent, in the framework of shape-centered representations. The connections between the modules avails the possibility to feed information back from higher to lower layers and optimize the design choices there. This thesis provides a framework looking at static phenomena but the presented approach could be extended to the analysis of dynamic scenes as well.}, web_url = {http://www.logos-verlag.de/cgi-bin/engbuchmid?isbn=2820&lng=deu&id=}, publisher = {Logos-Verlag}, address = {Berlin, Germany}, series = {MPI Series in Biological Cybernetics ; 27}, state = {published}, ISBN = {978-3-8325-2820-1}, author = {Engel D{engel}{Department Human Perception, Cognition and Action}} } @Article{ 6457, title = {Enhancement in Operator's Perception of Soft Tissues and Its Experimental Validation for Scaled Teleoperation Systems}, journal = {IEEE/ASME Transactions on Mechatronics}, year = {2011}, month = {12}, volume = {16}, number = {6}, pages = {1096-1109}, abstract = {This paper focuses on scaled teleoperation systems interacting with soft tissues and presents an optimal control scheme to maximize the operator's kinesthetic perception of remote soft environments while maintaining the stability in macro–micro interactions. Two performance metrics are defined to quantify the kinesthetic perception of the surgeons and the position tracking ability of the master–slave system. Kinesthetic perception is defined based on psychophysics by using two metrics, which relate to the detection and discrimination of stimulus. This paper then employs a multiconstrained optimization approach to get an optimal solution in the presence of the stability-performance tradeoff wherein the objective is to enhance the kinesthetic perception while maintaining the tracking and robust stability for interactions between macro and microworlds. Simplified stability constraints for scaled teleoperation systems are designed based on Llewellyn's absolute stability criterion for the optimization procedure, which provides easy and effective design guidelines for selecting control gains. Experiments with phantom soft tissues have been conducted using scaled force–position control architecture, scaled position–position control architecture, and scaled four-channel control architecture to verify the proposed control scheme. Results prove the effectiveness of this algorithm in enhancing the kinesthetic perception of surgeons for scaled teleoperation systems. Psychophysical experiments were then performed to compare our approach with similar contemporary research methods that further validated its efficacy.}, web_url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5605252&tag=1}, state = {published}, DOI = {10.1109/TMECH.2010.2076826}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Bhattacharjee T and Hashimoto H} } @Article{ FlemingHB2011, title = {Estimation of 3D shape from image orientations}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, year = {2011}, month = {12}, volume = {108}, number = {51}, pages = {20438-20443}, abstract = {One of the main functions of vision is to estimate the 3D shape of objects in our environment. Many different visual cues, such as stereopsis, motion parallax, and shading, are thought to be involved. One important cue that remains poorly understood comes from surface texture markings. When a textured surface is slanted in 3D relative to the observer, the surface patterns appear compressed in the retinal image, providing potentially important information about 3D shape. What is not known, however, is how the brain actually measures this information from the retinal image. Here, we explain how the key information could be extracted by populations of cells tuned to different orientations and spatial frequencies, like those found in the primary visual cortex. To test this theory, we created stimuli that selectively stimulate such cell populations, by “smearing” (filtering) images of 2D random noise into specific oriented patterns. We find that the resulting patterns appear vividly 3D, and that increasing the strength of the orientation signals progressively increases the sense of 3D shape, even though the filtering we apply is physically inconsistent with what would occur with a real object. This finding suggests we have isolated key mechanisms used by the brain to estimate shape from texture. Crucially, we also find that adapting the visual system's orientation detectors to orthogonal patterns causes unoriented random noise to look like a specific 3D shape. Together these findings demonstrate a crucial role of orientation detectors in the perception of 3D shape.}, web_url = {http://www.pnas.org/content/108/51/20438.full.pdf+html}, state = {published}, DOI = {10.1073/pnas.1114619109}, author = {Fleming RW{roland}{Department Human Perception, Cognition and Action}, Holtmann-Rice D{dhr}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ LeeN2011_2, title = {Long-term music training tunes how the brain temporally binds signals from multiple senses}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, year = {2011}, month = {12}, volume = {108}, number = {51}, pages = {E1441-E1450}, abstract = {Practicing a musical instrument is a rich multisensory experience involving the integration of visual, auditory, and tactile inputs with motor responses. This combined psychophysics–fMRI study used the musician's brain to investigate how sensory-motor experience molds temporal binding of auditory and visual signals. Behaviorally, musicians exhibited a narrower temporal integration window than nonmusicians for music but not for speech. At the neural level, musicians showed increased audiovisual asynchrony responses and effective connectivity selectively for music in a superior temporal sulcus-premotor-cerebellar circuitry. Critically, the premotor asynchrony effects predicted musicians’ perceptual sensitivity to audiovisual asynchrony. Our results suggest that piano practicing fine tunes an internal forward model mapping from action plans of piano playing onto visible finger movements and sounds. This internal forward model furnishes more precise estimates of the relative audiovisual timings and hence, stronger prediction error signals specifically for asynchronous music in a premotor-cerebellar circuitry. Our findings show intimate links between action production and audiovisual temporal binding in perception.}, web_url = {http://www.pnas.org/content/108/51/E1441.full.pdf+html}, state = {published}, DOI = {10.1073/pnas.1115267108}, author = {Lee HL{hweeling}{Research Group Cognitive Neuroimaging} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Article{ ChillerGlausSHKK2011, title = {Recognition of emotion in moving and static composite faces}, journal = {Swiss Journal of Psychology}, year = {2011}, month = {12}, volume = {70}, number = {4}, pages = {233-240}, abstract = {This paper investigates whether the greater accuracy of emotion identification for dynamic versus static expressions, as noted in previous research, can be explained through heightened levels of either component or configural processing. Using a paradigm by Young, Hellawell, and Hay (1987), we tested recognition performance of aligned and misaligned composite faces with six basic emotions (happiness, fear, disgust, surprise, anger, sadness). Stimuli were created using 3D computer graphics and were shown as static peak expressions (static condition) and 7 s video sequences (dynamic condition). The results revealed that, overall, moving stimuli were better recognized than static faces, although no interaction between motion and other factors was found. For happiness, sadness, and surprise, misaligned composites were better recognized than aligned composites, suggesting that aligned composites fuse to form a single expression, while the two halves of misaligned composites are perceived as two separate emotions. For anger, disgust, and fear, this was not the case. These results indicate that emotions are perceived on the basis of both configural and component-based information, with specific activation patterns for separate emotions, and that motion has a quality of its own and does not increase configural or component-based recognition separately.}, web_url = {http://psycnet.apa.org/journals/sjp/70/4/233.pdf}, state = {published}, DOI = {10.1024/1421-0185/a000061}, author = {Chiller-Glaus SD, Schwaninger A{aschwan}{Department Human Perception, Cognition and Action}, Hofer F, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action} and Knappmeyer B{babsy}{Department Human Perception, Cognition and Action}} } @Article{ SoumanRSFTUDBE2011, title = {CyberWalk: Enabling unconstrained omnidirectional walking through virtual environments}, journal = {ACM Transactions on Applied Perception}, year = {2011}, month = {11}, volume = {8}, number = {4:25}, pages = {1-22}, abstract = {Despite many recent developments in Virtual Reality, an effective locomotion interface which allows for normal walking through large virtual environments was still lacking until recently. Here, we describe the new CyberWalk omnidirectional treadmill system, which makes it possible for users to walk endlessly in any direction, while never leaving the confines of the limited walking surface. The treadmill system improves on previous designs, both in its mechanical features and in the control system employed to keep users close to the centre of the treadmill. As a result, users are able to start walking, vary their walking speed and direction, and stop walking like they would on a normal, stationary surface. The treadmill system was validated in two experiments, in which both the walking behaviour and the performance in a basic spatial updating task were compared to that during normal overground walking. The results suggest that walking on the CyberWalk treadmill is very close to normal walking, especially after some initial familiarization. Moreover, we did not find a detrimental effect of treadmill walking in the spatial updating task. The CyberWalk system constitutes a significant step forward to bringing the real world into the laboratory or workplace.}, web_url = {http://dl.acm.org/citation.cfm?id=2043607&dl=ACM&coll=DL&CFID=62552168&CFTOKEN=60220994}, state = {published}, DOI = {10.1145/2043603.2043607}, author = {Souman JL{souman}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Schwaiger M, Frissen I{ifrissen}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Th\"ummel T, Ulbrich H, De Luca A, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Ernst M{marc}{Research Group Multisensory Perception and Action}} } @Article{ TeramotoR2011, title = {Dynamic visual information facilitates object recognition from novel viewpoints}, journal = {Journal of Vision}, year = {2011}, month = {11}, volume = {10}, number = {13:11}, pages = {1-13}, abstract = {Normally, people have difficulties recognizing objects from novel as compared to learned views, resulting in increased reaction times and errors. Recent studies showed, however, that this “view-dependency” can be reduced or even completely eliminated when novel views result from observer's movements instead of object movements. This observer movement benefit was previously attributed to extra-retinal (physical motion) cues. In two experiments, we demonstrate that dynamic visual information (that would normally accompany observer's movements) can provide a similar benefit and thus a potential alternative explanation. Participants performed sequential matching tasks for Shepard–Metzler-like objects presented via head-mounted display. As predicted by the literature, object recognition performance improved when view changes (45° or 90°) resulted from active observer movements around the object instead of object movements. Unexpectedly, however, merely providing dynamic visual information depicting the viewpoint change showed an equal benefit, despite the lack of any extra-retinal/physical self-motion cues. Moreover, visually simulated rotations of the table and hidden target object (table movement condition) yielded similar performance benefits as simulated viewpoint changes (scene movement condition). These findings challenge the prevailing notion that extra-retinal (physical motion) cues are required for facilitating object recognition from novel viewpoints, and highlight the importance of dynamic visual cues, which have previously received little attention.}, web_url = {http://www.journalofvision.org/content/10/13/11.abstract}, state = {published}, DOI = {10.1167/10.13.11}, author = {Teramoto W{teraw}{Department Human Perception, Cognition and Action} and Riecke BE{bernie}{Department Human Perception, Cognition and Action}} } @Article{ ArmannJCR2011, title = {Race-specific norms for coding face identity and a functional role for norms}, journal = {Journal of Vision}, year = {2011}, month = {11}, volume = {11}, number = {13:9}, pages = {1-14}, abstract = {Models of face perception often adopt a framework in which faces are represented as points or vectors in a multidimensional space, relative to the average face that serves as a norm for encoding. Since faces are very similar in their configuration and share many visual properties, they could be encoded in one common space against one norm. However, certain face properties may result in grouping and “subclassification” of similar faces. We studied the processing of faces of different races, using high-level aftereffects, where exposure to one face systematically distorts the perception of a subsequently viewed face toward the “opposite” identity in face space. We measured identity aftereffects for adapt–test pairs that were opposite relative to race-specific (Asian and Caucasian) averages and pairs that were opposite relative to a “generic” average (both races morphed together). Aftereffects were larger for race-specific compared to mixed-race adapt–test pairs. These results suggest that race-specific norms are used to code identity because aftereffects are generally larger for adapt–test pairs drawn from trajectories passing through the norm (opposite pairs) than for those that do not. We also found that identification thresholds were lower when targets were distributed around race-specific averages than around the mixed-race average, suggesting that norm-based face encoding may play a functional role in facilitating identity discrimination.}, web_url = {http://www.journalofvision.org/content/11/13/9.full.pdf+html}, state = {published}, DOI = {10.1167/11.13.9}, author = {Armann R{armann}{Department Human Perception, Cognition and Action}, Jeffery L, Calder AJ and Rhodes G} } @Article{ LinkenaugerMP2011, title = {Body-based perceptual rescaling revealed through the size-weight illusion}, journal = {Perception}, year = {2011}, month = {10}, volume = {40}, number = {10}, pages = {1251-1253}, abstract = {An embodied approach to the perception of spatial layout contends that the body is used as a ‘perceptual ruler’ with which individuals scale the perceived environmental layout. In support of this notion, previous research has shown that the perceived size of objects can be influenced by changes in the apparent size of hand. The size – weight illusion is a well known phenomenon, which occurs when people lift two objects of equal weight but differing sizes and perceive that the larger object feels lighter. Therefore, if apparent hand size influences perceived object size, it should also influence the object’s perceived weight. In this study, we investigated this possibility by using perceived weight as a measure and found that changes in the apparent size of the hand influence objects’ perceived weight.}, web_url = {http://www.perceptionweb.com/perception/fulltext/p40/p7049.pdf}, state = {published}, DOI = {10.1068/p7049}, author = {Linkenauger SA{sally}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and Proffitt DR} } @Article{ LeeLBJP2011, title = {Putting Like a Pro: The Role of Positive Contagion in Golf Performance and Perception}, journal = {PLoS One}, year = {2011}, month = {10}, volume = {6}, number = {10}, pages = {1-4}, abstract = {Many amateur athletes believe that using a professional athlete's equipment can improve their performance. Such equipment can be said to be affected with positive contagion, which refers to the belief of transference of beneficial properties between animate persons/objects to previously neutral objects. In this experiment, positive contagion was induced by telling participants in one group that a putter previously belonged to a professional golfer. The effect of positive contagion was examined for perception and performance in a golf putting task. Individuals who believed they were using the professional golfer's putter perceived the size of the golf hole to be larger than golfers without such a belief and also had better performance, sinking more putts. These results provide empirical support for anecdotes, which allege that using objects with positive contagion can improve performance, and further suggest perception can be modulated by positive contagion.}, web_url = {http://www.plosone.org/article/fetchObjectAttachment.action?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0026016&representation=PDF}, state = {published}, DOI = {10.1371/journal.pone.0026016}, EPUB = {e26016}, author = {Lee C, Linkenauger SA{sally}{Department Human Perception, Cognition and Action}, Bakdash JZ, Joy-Gaba JA and Profitt DR} } @Article{ DahlLBW2011, title = {Second-Order Relational Manipulations Affect Both Humans and Monkeys}, journal = {PLoS One}, year = {2011}, month = {10}, volume = {6}, number = {10}, pages = {1-7}, abstract = {Recognition and individuation of conspecifics by their face is essential for primate social cognition. This ability is driven by a mechanism that integrates the appearance of facial features with subtle variations in their configuration (i.e., second-order relational properties) into a holistic representation. So far, there is little evidence of whether our evolutionary ancestors show sensitivity to featural spatial relations and hence holistic processing of faces as shown in humans. Here, we directly compared macaques with humans in their sensitivity to configurally altered faces in upright and inverted orientations using a habituation paradigm and eye tracking technologies. In addition, we tested for differences in processing of conspecific faces (human faces for humans, macaque faces for macaques) and non-conspecific faces, addressing aspects of perceptual expertise. In both species, we found sensitivity to second-order relational properties for conspecific (expert) faces, when presented in upright, not in inverted, orientation. This shows that macaques possess the requirements for holistic processing, and thus show similar face processing to that of humans.}, web_url = {http://www.plosone.org/article/fetchObjectAttachment.action;jsessionid=479810543A9D0DDB1F0DBC45F84CA66C.ambra02?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0025793&representation=PDF}, state = {published}, DOI = {10.1371/journal.pone.0025793}, EPUB = {e25793}, author = {Dahl CD{dahl}{Department Human Perception, Cognition and Action}{Department Physiology of Cognitive Processes}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Article{ LinkenaugerWP2011, title = {Taking a hands-on approach: Apparent grasping ability scales the perception of object size}, journal = {Journal of Experimental Psychology: Human Perception and Performance}, year = {2011}, month = {10}, volume = {37}, number = {5}, pages = {1432-1441}, abstract = {We examined whether the apparent size of an object is scaled to the morphology of the relevant body part with which one intends to act on it. To be specific, we tested if the visually perceived size of graspable objects is scaled to the extent of apparent grasping ability for the individual. Previous research has shown that right-handed individuals perceive their right hand as larger and capable of grasping larger objects than their left. In the first 2 experiments, we found that objects looked smaller when placed in or judged relative to their right hand compared to their left. In the third experiment, we directly manipulated apparent hand size by magnifying the participants' hands. Participants perceived objects to be smaller when their hand was magnified than when their hand was unmagnified. We interpret these results as demonstrating that perceivers use the extent of their hands' grasping abilities as “perceptual rulers” to scale the apparent size of graspable objects. Furthermore, hand size manipulations did not affect the perceived size of objects too big to be grasped, which suggests that hand size is only used as a scaling mechanism when the object affords the relevant action, in this case, grasping.}, web_url = {http://psycnet.apa.org/journals/xhp/37/5/1432.pdf}, state = {published}, DOI = {10.1037/a0024248}, author = {Linkenauger SA{sally}{Department Human Perception, Cognition and Action}, Witt JK and Proffitt DR} } @Article{ DoddsMB2011, title = {Talk to the Virtual Hands: Self-Animated Avatars Improve Communication in Head-Mounted Display Virtual Environments}, journal = {PLoS One}, year = {2011}, month = {10}, volume = {6}, number = {10}, pages = {1-12}, abstract = {Background When we talk to one another face-to-face, body gestures accompany our speech. Motion tracking technology enables us to include body gestures in avatar-mediated communication, by mapping one's movements onto one's own 3D avatar in real time, so the avatar is self-animated. We conducted two experiments to investigate (a) whether head-mounted display virtual reality is useful for researching the influence of body gestures in communication; and (b) whether body gestures are used to help in communicating the meaning of a word. Participants worked in pairs and played a communication game, where one person had to describe the meanings of words to the other. Principal Findings In experiment 1, participants used significantly more hand gestures and successfully described significantly more words when nonverbal communication was available to both participants (i.e. both describing and guessing avatars were self-animated, compared with both avatars in a static neutral pose). Participants ‘passed’ (gave up describing) significantly more words when they were talking to a static avatar (no nonverbal feedback available). In experiment 2, participants' performance was significantly worse when they were talking to an avatar with a prerecorded listening animation, compared with an avatar animated by their partners' real movements. In both experiments participants used significantly more hand gestures when they played the game in the real world. Conclusions Taken together, the studies show how (a) virtual reality can be used to systematically study the influence of body gestures; (b) it is important that nonverbal communication is bidirectional (real nonverbal feedback in addition to nonverbal communication from the describing participant); and (c) there are differences in the amount of body gestures that participants use with and without the head-mounted display, and we discuss possible explanations for this and ideas for future investigation.}, file_url = {fileadmin/user_upload/files/publications/2011/Dodds-TalktotheVirtualHands-PLoSOne-2011.pdf}, web_url = {http://www.plosone.org/article/fetchObjectAttachment.action;jsessionid=BB8DF7295C39A064E5FFC9839EC935BD.ambra01?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0025759&representation=PDF}, state = {published}, DOI = {10.1371/journal.pone.0025759}, EPUB = {e25759}, author = {Dodds TJ{dodds}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ StreuberKSBd2011, title = {The effect of social context on the use of visual information}, journal = {Experimental Brain Research}, year = {2011}, month = {10}, volume = {214}, number = {2}, pages = {273-284}, abstract = {Social context modulates action kinematics. Less is known about whether social context also affects the use of task relevant visual information. We tested this hypothesis by examining whether the instruction to play table tennis competitively or cooperatively affected the kind of visual cues necessary for successful table tennis performance. In two experiments, participants played table tennis in a dark room with only the ball, net, and table visible. Visual information about both players’ actions was manipulated by means of self-glowing markers. We recorded the number of successful passes for each player individually. The results showed that participants’ performance increased when their own body was rendered visible in both the cooperative and the competitive condition. However, social context modulated the importance of different sources of visual information about the other player. In the cooperative condition, seeing the other player’s racket had the largest effects on performance increase, whereas in the competitive condition, seeing the other player’s body resulted in the largest performance increase. These results suggest that social context selectively modulates the use of visual information about others’ actions in social interactions.}, web_url = {http://www.springerlink.com/content/b014430023h47417/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-011-2830-9}, author = {Streuber S{stst}{Department Human Perception, Cognition and Action}, Knoblich G, Sebanz N, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}} } @Article{ SchomakerTBB2011, title = {It is all me: the effect of viewpoint on visual–vestibular recalibration}, journal = {Experimental Brain Research}, year = {2011}, month = {9}, volume = {243}, number = {2-3}, pages = {245-256}, abstract = {Participants performed a visual–vestibular motor recalibration task in virtual reality. The task consisted of keeping the extended arm and hand stable in space during a whole-body rotation induced by a robotic wheelchair. Performance was first quantified in a pre-test in which no visual feedback was available during the rotation. During the subsequent adaptation phase, optical flow resulting from body rotation was provided. This visual feedback was manipulated to create the illusion of a smaller rotational movement than actually occurred, hereby altering the visual–vestibular mapping. The effects of the adaptation phase on hand stabilization performance were measured during a post-test that was identical to the pre-test. Three different groups of subjects were exposed to different perspectives on the visual scene, i.e., first-person, top view, or mirror view. Sensorimotor adaptation occurred for all three viewpoint conditions, performance in the post-test session showing a marked under-compensation relative to the pre-test performance. In other words, all viewpoints gave rise to a remapping between vestibular input and the motor output required to stabilize the arm. Furthermore, the first-person and mirror view adaptation induced a significant decrease in variability of the stabilization performance. Such variability reduction was not observed for the top view adaptation. These results suggest that even if all three viewpoints can evoke substantial adaptation aftereffects, the more naturalistic first-person view and the richer mirror view should be preferred when reducing motor variability constitutes an important issue.}, web_url = {http://www.springerlink.com/content/d195u587t5141836/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-011-2723-y}, author = {Schomaker J{jschomaker}{Department Human Perception, Cognition and Action}, Tesch J{jtesch}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Bresciani JP{bresciani}{Department Human Perception, Cognition and Action}} } @Article{ GaissertBW2011, title = {Similarity and categorization: From vision to touch}, journal = {Acta Psychologica}, year = {2011}, month = {9}, volume = {138}, number = {1}, pages = {219-230}, abstract = {Even though human perceptual development relies on combining multiple modalities, most categorization studies so far have focused on the visual modality. To better understand the mechanisms underlying multisensory categorization, we analyzed visual and haptic perceptual spaces and compared them with human categorization behavior. As stimuli we used a three-dimensional object space of complex, parametrically-defined objects. First, we gathered similarity ratings for all objects and analyzed the perceptual spaces of both modalities using multidimensional scaling analysis. Next, we performed three different categorization tasks which are representative of every-day learning scenarios: in a fully unconstrained task, objects were freely categorized, in a semi-constrained task, exactly three groups had to be created, whereas in a constrained task, participants received three prototype objects and had to assign all other objects accordingly. We found that the haptic modality was on par with the visual modality both in recovering the topology of the physical space and in solving the categorization tasks. We also found that within-category similarity was consistently higher than across-category similarity for all categorization tasks and thus show how perceptual spaces based on similarity can explain visual and haptic object categorization. Our results suggest that both modalities employ similar processes in forming categories of complex objects.}, web_url = {http://www.sciencedirect.com/science?_ob=MiamiImageURL&_cid=272045&_user=29041&_pii=S0001691811001302&_check=y&_origin=&_coverDate=30-Sep-2011&view=c&wchp=dGLbVBA-zSkzk&md5=8320348e946ed057a766d4d041954797/1-s2.0-S0001691811001302-main.pdf}, state = {published}, DOI = {10.1016/j.actpsy.2011.06.007}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Article{ ButlerCBS2011, title = {The Role of Stereo Vision in Visual-Vestibular Integration}, journal = {Seeing and Perceiving}, year = {2011}, month = {9}, volume = {24}, number = {5}, pages = {453-470}, abstract = {Self-motion through an environment stimulates several sensory systems, including the visual system and the vestibular system. Recent work in heading estimation has demonstrated that visual and vestibular cues are typically integrated in a statistically optimal manner, consistent with Maximum Likelihood Estimation predictions. However, there has been some indication that cue integration may be affected by characteristics of the visual stimulus. Therefore, the current experiment evaluated whether presenting optic flow stimuli stereoscopically, or presenting both eyes with the same image (binocularly) affects combined visual-vestibular heading estimates. Participants performed a two-interval forced-choice task in which they were asked which of two presented movements was more rightward. They were presented with either visual cues alone, vestibular cues alone or both cues combined. Measures of reliability were obtained for both binocular and stereoscopic conditions. Group level analyses demonstrated that when stereoscopic information was available there was clear evidence of optimal integration, yet when only binocular information was available weaker evidence of cue integration was observed. Exploratory individual analyses demonstrated that for the stereoscopic condition 90% of participants exhibited optimal integration, whereas for the binocular condition only 60% of participants exhibited results consistent with optimal integration. Overall, these findings suggest that stereo vision may be important for self-motion perception, particularly under combined visual-vestibular conditions.}, web_url = {http://www.ingentaconnect.com/content/brill/sp/2011/00000024/00000005/art00002}, state = {published}, DOI = {10.1163/187847511X588070}, author = {Butler JS{butler}{Department Human Perception, Cognition and Action}, Campos JL{camposjl}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Smith ST{stusmith}} } @Article{ 5643, title = {The integration of spatial information across different viewpoints}, journal = {Memory & Cognition}, year = {2011}, month = {8}, volume = {39}, number = {6}, pages = {1042-1054}, abstract = {The integration of spatial information perceived from different viewpoints is a frequent, yet largely unexplored, cognitive ability. In two experiments, participants saw two presentations, each consisting of three targets—that is, illuminated tiles on the floor—before walking the shortest possible path across all targets. In Experiment 1, participants viewed the targets either from the same viewpoint or from different viewpoints. Errors in recalling targets increased if participants changed their viewpoints between presentations, suggesting that memory acquired from different viewpoints had to be aligned for integration. Furthermore, the error pattern indicates that memory for the first presentation was transformed into the reference frame of the second presentation. In Experiment 2, we examined whether this transformation occurred because new information was integrated already during encoding or because memorized information was integrated when required. Results suggest that the latter is the case. This might serve as a strategy for avoiding additional alignments.}, web_url = {http://www.springerlink.com/content/147416m6637051k2/fulltext.pdf}, state = {published}, DOI = {10.3758/s13421-011-0088-x}, author = {Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Wiener JM{malte} and Berthoz A} } @Article{ 6789, title = {Contributions of the PPC to online control of visually guided reaching movements assessed with fMRI-guided TMS}, journal = {Cerebral Cortex}, year = {2011}, month = {7}, volume = {21}, number = {7}, pages = {1602-1612}, abstract = {The posterior parietal cortex (PPC) plays an important role in controlling voluntary movements by continuously integrating sensory information about body state and the environment. We tested which subregions of the PPC contribute to the processing of target- and body-related visual information while reaching for an object, using a reaching paradigm with 2 types of visual perturbation: displacement of the visual target and displacement of the visual feedback about the hand position. Initially, functional magnetic resonance imaging (fMRI) was used to localize putative target areas involved in online corrections of movements in response to perturbations. The causal contribution of these areas to online correction was tested in subsequent neuronavigated transcranial magnetic stimulation (TMS) experiments. Robust TMS effects occurred at distinct anatomical sites along the anterior intraparietal sulcus (aIPS) and the anterior part of the supramarginal gyrus for both perturbations. TMS over neighboring sites did not affect online control. Our results support the hypothesis that the aIPS is more generally involved in visually guided control of movements, independent of body effectors and nature of the visual information. Furthermore, they suggest that the human network of PPC subregions controlling goal-directed visuomotor processes extends more inferiorly than previously thought. Our results also point toward a good spatial specificity of the TMS effects.}, file_url = {/fileadmin/user_upload/files/publications/Cerebral-Cortex-2010-Reichenbach_6789[0].pdf}, web_url = {http://cercor.oxfordjournals.org/content/21/7/1602.full.pdf+html}, state = {published}, DOI = {10.1093/cercor/bhq225}, author = {Reichenbach A{areichen}{Department Human Perception, Cognition and Action}{Department High-Field Magnetic Resonance}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}, Peer A, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Thielscher A{thielscher}{Department High-Field Magnetic Resonance}} } @Article{ 6455, title = {Effect of Scaling on the Performance and Stability of Teleoperation Systems Interacting with Soft Environments}, journal = {Advanced Robotics}, year = {2011}, month = {7}, volume = {25}, number = {11}, pages = {1577-1601}, abstract = {There is generally a tradeoff between stability and performance in haptic control systems. Teleoperation systems with haptic feedback are no exception. Scaling in these systems used in applications such as telemicrosurgical systems has further effects on the stability and performance. This paper focuses on those applications interacting with soft tissues and analyzes the effects of the scaling in an effort to increase the performance of these systems while maintaining the stability. Position tracking and kinesthetic perception are especially important in the tele-surgical systems and, hence, are used as the performance criteria. Quantitatively defined stability robustness, which is based on Llewellyn's absolute stability criterion, is used as a metric for stability analysis. Various choices of scaling factors, and human and environment impedances are then investigated. The proposed kinesthetic perception concept is validated using psychophysical experiments. Widely used bilateral control architectures such as the two-channel position-position, two-channel force-position and four-channel controls are specifically analyzed and evaluated using simulations and experiments with phantom soft tissues. Results also show that the force-position control architecture shows the best position tracking performance irrespective of the scaling factors while the four-channel controller shows the best kinesthetic perception capability.}, web_url = {http://www.ingentaconnect.com/search/download;jsessionid=5cti7430ec5kb.alexandra?pub=infobike%3a%2f%2fvsp%2farb%2f2011%2f00000025%2f00000011%2fart00011&mimetype=application%2fpdf&exitTargetId=1311077540702}, state = {published}, DOI = {10.1163/016918611X579547}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Bhattacharjee T and Hashimoto H} } @Article{ FrissenCSE2011, title = {Integration of vestibular and proprioceptive signals for spatial updating}, journal = {Experimental Brain Research}, year = {2011}, month = {7}, volume = {212}, number = {2}, pages = {163-176}, abstract = {Spatial updating during self-motion typically involves the appropriate integration of both visual and non-visual cues, including vestibular and proprioceptive information. Here, we investigated how human observers combine these two non-visual cues during full-stride curvilinear walking. To obtain a continuous, real-time estimate of perceived position, observers were asked to continuously point toward a previously viewed target in the absence of vision. They did so while moving on a large circular treadmill under various movement conditions. Two conditions were designed to evaluate spatial updating when information was largely limited to either proprioceptive information (walking in place) or vestibular information (passive movement). A third condition evaluated updating when both sources of information were available (walking through space) and were either congruent or in conflict. During both the passive movement condition and while walking through space, the pattern of pointing behavior demonstrated evidence of accurate egocentric updating. In contrast, when walking in place, perceived self-motion was underestimated and participants always adjusted the pointer at a constant rate, irrespective of changes in the rate at which the participant moved relative to the target. The results are discussed in relation to the maximum likelihood estimation model of sensory integration. They show that when the two cues were congruent, estimates were combined, such that the variance of the adjustments was generally reduced. Results also suggest that when conflicts were introduced between the vestibular and proprioceptive cues, spatial updating was based on a weighted average of the two inputs.}, web_url = {http://www.springerlink.com/content/cgju26276732uln0/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-011-2717-9}, author = {Frissen I{ifrissen}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Campos JL{camposjl}{Department Human Perception, Cognition and Action}, Souman JL{souman}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Article{ 5923, title = {Effects of visual–haptic asynchronies and loading–unloading movements on compliance perception}, journal = {Brain Research Bulletin}, year = {2011}, month = {6}, volume = {85}, number = {5}, pages = {245-259}, abstract = {Spring compliance is perceived by combining the sensed force exerted by the spring with the displacement caused by the action (sensed through vision and proprioception). We investigated the effect of delay of visual and force information with respect to proprioception to understand how visual–haptic perception of compliance is achieved. First, we confirm an earlier result that force delay increases perceived compliance. Furthermore, we find that perceived compliance decreases with a delay in the visual information. These effects of delay on perceived compliance would not be present if the perceptual system would utilize all force–displacement information available during the interaction. Both delays generate a bias in compliance which is opposite in the loading and unloading phases of the interaction. To explain these findings, we propose that information during the loading phase of the spring displacement is weighted more than information obtained during unloading. We confirm this hypothesis by showing that sensitivity to compliance during loading movements is much higher than during unloading movements. Moreover, we show that visual and proprioceptive information about the hand position are used for compliance perception depending on the sensitivity to compliance. Finally, by analyzing participants’ movements we show that these two factors (loading/unloading and reliability) account for the change in perceived compliance due to visual and force delays.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6SYT-4YH4PW9-1-2&_cdi=4843&_user=29041&_pii=S0361923010000535&_origin=&_coverDate=06%2F30%2F2011&_sk=999149994&view=c&wchp=dGLbVzW-zSkWz&md5=9431a6ab71ceec50cfd48eed7c02f605&ie=/sdarticle.pdf}, state = {published}, DOI = {10.1016/j.brainresbull.2010.02.009}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Kn\"orlein B, Ernst MO{marc}{Research Group Multisensory Perception and Action} and Harders M} } @Article{ FlemingJM2011, title = {Visual Perception of Thick Transparent Materials}, journal = {Psychological Science}, year = {2011}, month = {6}, volume = {22}, number = {6}, pages = {812-820}, abstract = {Under typical viewing conditions, human observers readily distinguish between materials such as silk, marmalade, or granite, an achievement of the visual system that is poorly understood. Recognizing transparent materials is especially challenging. Previous work on the perception of transparency has focused on objects composed of flat, infinitely thin filters. In the experiments reported here, we considered thick transparent objects, such as ice cubes, which are irregular in shape and can vary in refractive index. An important part of the visual evidence signaling the presence of such objects is distortions in the perceived shape of other objects in the scene. We propose a new class of visual cues derived from the distortion field induced by thick transparent objects, and we provide experimental evidence that cues arising from the distortion field predict both the successes and the failures of human perception in judging refractive indices.}, web_url = {http://pss.sagepub.com/content/22/6/812.full.pdf+html}, state = {published}, DOI = {10.1177/0956797611408734}, author = {Fleming RW{roland}{Department Human Perception, Cognition and Action}, J\"akel F{frank} and Maloney LT{ltm}} } @Article{ RuddleVB2011, title = {Walking improves your cognitive map in environments that are large-scale and large in extent}, journal = {ACM Transactions on Computer-Human Interaction}, year = {2011}, month = {6}, volume = {18}, number = {2:10}, pages = {1-22}, abstract = {This study investigated the effect of body-based information (proprioception, etc.) when participants navigated large-scale virtual marketplaces that were either small (Experiment 1) or large in extent (Experiment 2). Extent refers to the size of an environment, whereas scale refers to whether people have to travel through an environment to see the detail necessary for navigation. Each participant was provided with full body-based information (walking through the virtual marketplaces in a large tracking hall or on an omnidirectional treadmill), just the translational component of body-based information (walking on a linear treadmill, but turning with a joystick), just the rotational component (physically turning but using a joystick to translate) or no body-based information (joysticks to translate and rotate). In large and small environments translational body-based information significantly improved the accuracy of participants' cognitive maps, measured using estimates of direction and relative straight line distance but, on its own, rotational body-based information had no effect. In environments of small extent, full body-based information also improved participants' navigational performance. The experiments show that locomotion devices such as linear treadmills would bring substantial benefits to virtual environment applications where large spaces are navigated, and theories of human navigation need to reconsider the contribution made by body-based information, and distinguish between environmental scale and extent.}, web_url = {http://portal.acm.org/citation.cfm?doid=1970378.1970384}, state = {published}, DOI = {10.1145/1970378.1970384}, author = {Ruddle RA{roy}, Volkova E{evolk}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ RuddleVMB2011, title = {The effect of landmark and body-based sensory information on route knowledge}, journal = {Memory & Cognition}, year = {2011}, month = {5}, volume = {39}, number = {4}, pages = {686-699}, abstract = {Two experiments investigated the effects of landmarks and body-based information on route knowledge. Participants made four out-and-back journeys along a route, guided only on the first outward trip and with feedback every time an error was made. Experiment 1 used 3-D virtual environments (VEs) with a desktop monitor display, and participants were provided with no supplementary landmarks, only global landmarks, only local landmarks, or both global and local landmarks. Local landmarks significantly reduced the number of errors that participants made, but global landmarks did not. Experiment 2 used a head-mounted display; here, participants who physically walked through the VE (translational and rotational body-based information) made 36% fewer errors than did participants who traveled by physically turning but changing position using a joystick. Overall, the experiments showed that participants were less sure of where to turn than which way, and journey direction interacted with sensory information to affect the number and types of errors participants made.}, web_url = {http://www.springerlink.com/content/12771128x0716033/fulltext.pdf}, state = {published}, DOI = {10.3758/s13421-010-0054-z}, author = {Ruddle RA{roy}, Volkova E{evolk}{Department Human Perception, Cognition and Action}, Mohler B{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 6849, title = {Perceived Object Stability Depends on Multisensory Estimates of Gravity}, journal = {PLoS ONE}, year = {2011}, month = {4}, volume = {6}, number = {4}, pages = {1-5}, abstract = {Background How does the brain estimate object stability? Objects fall over when the gravity-projected centre-of-mass lies outside the point or area of support. To estimate an object's stability visually, the brain must integrate information across the shape and compare its orientation to gravity. When observers lie on their sides, gravity is perceived as tilted toward body orientation, consistent with a representation of gravity derived from multisensory information. We exploited this to test whether vestibular and kinesthetic information affect this visual task or whether the brain estimates object stability solely from visual information. Methodology/Principal Findings In three body orientations, participants viewed images of objects close to a table edge. We measured the critical angle at which each object appeared equally likely to fall over or right itself. Perceived gravity was measured using the subjective visual vertical. The results show that the perceived critical angle was significantly biased in the same direction as the subjective visual vertical (i.e., towards the multisensory estimate of gravity). Conclusions/Significance Our results rule out a general explanation that the brain depends solely on visual heuristics and assumptions about object stability. Instead, they suggest that multisensory estimates of gravity govern the perceived stability of objects, resulting in objects appearing more stable than they are when the head is tilted in the same direction in which they fall.}, web_url = {http://www.plosone.org/article/fetchObjectAttachment.action;jsessionid=C1AE6461C55EF186CAA1AB710C6E0EAA.ambra02?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0019289&representation=PDF}, state = {published}, DOI = {10.1371/journal.pone.0019289}, EPUB = {e19289}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Fleming RW{roland}{Department Human Perception, Cognition and Action}, Singh M and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 6642, title = {Design and implementation of decentralised supervisory control for manufacturing system automation}, journal = {International Journal of Computer Integrated Manufacturing}, year = {2011}, month = {3}, volume = {24}, number = {3}, pages = {242-256}, abstract = {Supervisory control theory, which was first proposed by Ramadge and Wonahm, is a well-suited control theory for the control of complex systems such as semiconductor manufacturing systems, automobile manufacturing systems, and chemical processes because these are better modelled by discrete event models than by differential or difference equation models at higher levels of abstraction. Moreover, decentralised supervisory control is an efficient method for large complex systems according to the divide-and-conquer principle. This article presents a solution and a design procedure of supervisory control problem for the case of decentralised control. We apply the proposed design procedure to an experimental miniature computer-integrated manufacturing (CIM) system. This article presents the design of fourteen modular supervisors and one high-level supervisor to control the experimental miniature CIM system. These supervisors are controllable, non-blocking, and non-conflicting. After the verification of the supervisors by simulation, the collision avoidance supervisors for automated guided vehicle system have been implemented to demonstrate their efficacy.}, web_url = {http://www.informaworld.com/smpp/content~db=all?content=10.1080/0951192X.2011.552530}, state = {published}, DOI = {10.1080/0951192X.2011.552530}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}} } @Article{ 6950, title = {Predicting direction detection thresholds for arbitrary translational acceleration profiles in the horizontal plane}, journal = {Experimental Brain Research}, year = {2011}, month = {3}, volume = {209}, number = {1}, pages = {95-107}, abstract = {In previous research, direction detection thresholds have been measured and successfully modeled by exposing participants to sinusoidal acceleration profiles of different durations. In this paper, we present measurements that reveal differences in thresholds depending not only on the duration of the profile, but also on the actual time course of the acceleration. The measurements are further explained by a model based on a transfer function, which is able to predict direction detection thresholds for all types of acceleration profiles. In order to quantify a participant’s ability to detect the direction of motion in the horizontal plane, a four-alternative forced-choice task was implemented. Three types of acceleration profiles (sinusoidal, trapezoidal and triangular) were tested for three different durations (1.5, 2.36 and 5.86 s). To the best of our knowledge, this is the first study which varies both quantities (profile and duration) in a systematic way within a single experiment. The lowest thresholds were found for trapezoidal profiles and the highest for triangular profiles. Simulations for frequencies lower than the ones actually measured predict a change from this behavior: Sinusoidal profiles are predicted to yield the highest thresholds at low frequencies. This qualitative prediction is only possible with a model that is able to predict thresholds for different types of acceleration profiles. Our modeling approach represents an important advancement, because it allows for a more general and accurate description of perceptual thresholds for simple and complex translational motions.}, web_url = {http://www.springerlink.com/content/l2086212j6121842/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-010-2523-9}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Beykirch K{kab}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 6313, title = {Audiovisual asynchrony detection in human speech}, journal = {Journal of Experimental Psychology: Human Perception and Performance}, year = {2011}, month = {2}, volume = {37}, number = {1}, pages = {245-256}, abstract = {Combining information from the visual and auditory senses can greatly enhance intelligibility of natural speech. Integration of audiovisual speech signals is robust even when temporal offsets are present between the component signals. In the present study, we characterized the temporal integration window for speech and nonspeech stimuli with similar spectrotemporal structure to investigate to what extent humans have adapted to the specific characteristics of natural audiovisual speech. We manipulated spectrotemporal structure of the auditory signal, stimulus length, and task context. Results indicate that the temporal integration window is narrower and more asymmetric for speech than for nonspeech signals. When perceiving audiovisual speech, subjects tolerate visual leading asynchronies, but are nevertheless very sensitive to auditory leading asynchronies that are less likely to occur in natural speech. Thus, speech perception may be fine-tuned to the natural statistics of audiovisual speech, where facial movements always occur before acoustic speech articulation.}, web_url = {http://psycnet.apa.org/psycarticles/2010-17527-001.pdf}, state = {published}, DOI = {10.1037/a0019952}, author = {Maier JX{jmaier}{Department Human Perception, Cognition and Action}, Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Article{ delaRosaCC2011, title = {Visual object detection, categorization, and identification tasks are associated with different time courses and sensitivities}, journal = {Journal of Experimental Psychology: Human Perception and Performance}, year = {2011}, month = {2}, volume = {37}, number = {1}, pages = {38-47}, abstract = {Recent evidence suggests that the recognition of an object's presence and its explicit recognition are temporally closely related. Here we re-examined the time course (using a fine and a coarse temporal resolution) and the sensitivity of three possible component processes of visual object recognition. In particular, participants saw briefly presented (Experiment I to III) or noise masked (Experiment IV) static images of objects and non-object textures. Participants reported the presence of an object, its basic level category, and its subordinate category while we measured recognition performance by means of accuracy and reaction times. All three recognition tasks were clearly separable in terms of their time course and sensitivity. Finally, the use of a coarser temporal sampling of presentation times decreased performance differences between the detection and basic level categorization task suggesting that a fine temporal sampling for the dissociation of recognition performances is important. Overall the three probed recognition processes were associated with different time courses and sensitivities.}, web_url = {http://psycnet.apa.org/journals/xhp/37/1/38.pdf}, state = {published}, DOI = {10.1037/a0020553}, author = {de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Choudhery RN{choudhery}{Department Human Perception, Cognition and Action} and Chatziastros A{astros}{Department Human Perception, Cognition and Action}} } @Article{ 6724, title = {Effects of transcranial magnetic stimulation on visual evoked potentials in a visual suppression task}, journal = {Neuroimage}, year = {2011}, month = {1}, volume = {54}, number = {2}, pages = {1375-1384}, abstract = {Transcranial magnetic stimulation (TMS) can non-invasively modify cortical neural activity by means of a time-varying magnetic field. For example, in cognitive neuroscience, it is applied to create reversible “virtual lesions” in healthy humans (usually assessed as diminished performance in a behavioral task), thereby helping to establish causal structure–function relationships. Despite its widespread use, it is still rather unclear how TMS acts on existing, task-related neural activity, potentially resulting in a measurable effect on the behavioral level. Here, we deliver TMS to early visual areas while recording EEG in order to directly characterize the interaction between TMS-evoked (TEPs) and visual-evoked potentials (VEPs). Simultaneously, the subjects‘ performance is assessed in a visual forced-choice task. This allows us to compare the TMS effects on the VEPs across different levels of behavioral impairment. By systematically varying the stimulation intensity, we demonstrate tha t TMS strongly enhances the overall visual stimulus-related activity (rather than disrupting it). This enhancement effect saturates when behavior is impaired. This might indicate that the neural coding of the visual stimulus is robust to noise within a certain dynamic range (as indexed by the enhancement). Strong disturbances might saturate this range, causing behavioral impairment. Variation of the timing between the visual stimulus and the magnetic pulse reveals a “constructive interference” between the TEPs and VEPs: The better the overlap between both evoked potentials, the stronger the interaction effect when TMS and visual stimulation are combined. Importantly, however, this effect is uncorrelated with the strength of behavioral impairment.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6WNP-50X2NG3-3-G&_cdi=6968&_user=29041&_pii=S1053811910011298&_origin=search&_coverDate=08%2F30%2F2010&_sk=999999999&view=c&wc}, state = {published}, DOI = {10.1016/j.neuroimage.2010.08.047}, author = {Reichenbach A{areichen}{Department Human Perception, Cognition and Action}{Department High-Field Magnetic Resonance}, Whittingstall K{kevin}{Department Physiology of Cognitive Processes} and Thielscher A{thielscher}{Department High-Field Magnetic Resonance}} } @Article{ 5746, title = {Perception-Motivated interpolation of image sequences}, journal = {ACM Transactions on Applied Perception}, year = {2011}, month = {1}, volume = {8}, number = {2}, pages = {1-28}, abstract = {We present a method for image interpolation that is able to create high-quality, perceptually convincing transitions between recorded images. By implementing concepts derived from human vision, the problem of a physically correct image interpolation is relaxed to that of image interpolation which is perceived as visually correct by human observers. We find that it suffices to focus on exact edge correspondences, homogeneous regions and coherent motion to compute convincing results. A user study confirms the visual quality of the proposed image interpolation approach. We show how each aspect of our approach increases perceived quality of the result. We compare the results to other methods and assess achievable quality for different types of scenes.}, web_url = {http://dl.acm.org/citation.cfm?doid=1870076.1870079}, state = {published}, DOI = {10.1145/1870076.1870079}, author = {Stich T, Linz C, Wallraven C{walli}{Department Human Perception, Cognition and Action}, Cunningham DW{dwc}{Department Human Perception, Cognition and Action} and Magnor M} } @Article{ 6442, title = {Visual influences on path integration in darkness indicates a multimodal representation of large-scale space}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, year = {2011}, month = {1}, volume = {108}, number = {3}, pages = {1152-1157}, abstract = {Our ability to return to the start of a route recently performed in darkness is thought to reflect path integration of motion-related information. Here we provide evidence that motion-related interoceptive representations (proprioceptive, vestibular, and motor efference copy) combine with visual representations to form a single multimodal representation guiding navigation. We used immersive virtual reality to decouple visual input from motion-related interoception by manipulating the rotation or translation gain of the visual projection. First, participants walked an outbound path with both visual and interoceptive input, and returned to the start in darkness, demonstrating the influences of both visual and interoceptive information in a virtual reality environment. Next, participants adapted to visual rotation gains in the virtual environment, and then performed the path integration task entirely in darkness. Our findings were accurately predicted by a quantitative model in which visual and interoceptive inputs combine into a single multimodal representation guiding navigation, and are incompatible with a model of separate visual and interoceptive influences on action (in which path integration in darkness must rely solely on interoceptive representations). Overall, our findings suggest that a combined multimodal representation guides large-scale navigation, consistent with a role for visual imagery or a cognitive map.}, web_url = {http://www.pnas.org/content/108/3/1152.full.pdf+html}, state = {published}, DOI = {10.1073/pnas.1011843108}, author = {Tcheang L{ltcheang}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Burgess N} } @Article{ 6781, title = {Walk this way: Approaching bodies can influence the processing of faces}, journal = {Cognition}, year = {2011}, month = {1}, volume = {118}, number = {1}, pages = {17-31}, abstract = {A highly familiar type of movement occurs whenever a person walks towards you. In the present study, we investigated whether this type of motion has an effect on face processing. We took a range of different 3D head models and placed them on a single, identical 3D body model. The resulting figures were animated to approach the observer. In a first series of experiments, we used a sequential matching task to investigate how the motion of an approaching person affects immediate responses to faces. We compared observers’ responses following approach sequences to their performance with figures walking backwards (receding motion) or remaining still. Observers were significantly faster in responding to a target face that followed an approach sequence, compared to both receding and static primes. In a second series of experiments, we investigated long-term effects of motion using a delayed visual search paradigm. After studying moving or static avatars, observers searched for target faces in static arrays of varyin g set sizes. Again, observers were faster at responding to faces that had been learned in the context of an approach sequence. Together these results suggest that the context of a moving body influences face processing, and support the hypothesis that our visual system has mechanisms that aid the encoding of behaviourally-relevant and familiar dynamic events.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6T24-51CHMC4-1-H&_cdi=4908&_user=29041&_pii=S0010027710002179&_origin=browse&_coverDate=11%2F02%2F2010&_sk=999999999&view=c&wchp=dGLzVtz-zSkWA&md5=c8de6ee3037}, state = {published}, DOI = {10.1016/j.cognition.2010.09.004}, author = {Pilz KS{kpilz}{Department Human Perception, Cognition and Action}, Vuong QC{qvuong}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Thornton IM{ian}{Department Human Perception, Cognition and Action}} } @Inproceedings{ FranchiRB2011, title = {Distributed Online Leader Selection in the Bilateral Teleoperation of Multiple UAVs}, year = {2011}, month = {12}, pages = {3559-3565}, abstract = {For several applications like data collection, surveillance, search and rescue and exploration of wide areas, the use of a group of simple robots rather than a single complex robot has proven to be very effective and promising, and the problem of coordinating a group of agents has received a lot of attention over the last years. In this paper, we consider the challenge of establishing a bilateral force-feedback teleoperation channel between a human operator (the master side) and a remote multi-robot system (the slave side) where a special agent, the leader, is selected and directly controlled by the master. In particular, we study the problem of distributed online optimal leader selection, i.e., how to choose, and possibly change, the leader online in order to maximize some suitable criteria related to the tracking performance of the whole group w.r.t. the master commands. Human/hardware-in-the-loop simulation results with a group of UAVs support the theoretical claims of the paper.}, file_url = {fileadmin/user_upload/files/publications/2011/CDC-ECC-2011-Franchi.pdf}, web_url = {http://control.disp.uniroma2.it/cdcecc2011/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {50th IEEE Conference on Decision and Control and European Control Conference (CDC - ECC 2011)}, event_place = {Orlando, FL, USA}, state = {published}, DOI = {10.1109/CDC.2011.6160944}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ BrowatzkiFGBW2011, title = {Going into depth: Evaluating 2D and 3D cues for object classification on a new, large-scale object dataset}, year = {2011}, month = {11}, pages = {1189-1195}, abstract = {Categorization of objects solely based on shape and appearance is still a largely unresolved issue. With the advent of new sensor technologies, such as consumer-level range sensors, new possibilities for shape processing have become available for a range of new application domains. In the first part of this paper, we introduce a novel, large dataset containing 18 categories of objects found in typical household and office environments-we envision this dataset to be useful in many applications ranging from robotics to computer vision. The second part of the paper presents computational experiments on object categorization with classifiers exploiting both two-dimensional and three-dimensional information. We evaluate categorization performance for both modalities in separate and combined representations and demonstrate the advantages of using range data for object and shape processing skills.}, file_url = {fileadmin/user_upload/files/publications/2011/CD4CV-2011-Browatzki.pdf}, web_url = {http://www.vision.ee.ethz.ch/CDC4CV/index.html}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, booktitle = {2011 IEEE International Conference on Computer Vision Workshops (ICCV Workshops)}, event_name = {1st ICCV Workshop on Consumer Depth Cameras in Computer Vision (CD4CV2011)}, event_place = {Barcelona, Spain}, state = {published}, ISBN = {978-1-467-30062-9}, DOI = {10.1109/ICCVW.2011.6130385}, author = {Browatzki B{browatbn}{Department Human Perception, Cognition and Action}, Fischer J, Graf B, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Inproceedings{ NieuwenhuizenJPWPFSZFBSMSDGHB2011, title = {myCopter: Enabling Technologies for Personal Aerial Transportation Systems}, year = {2011}, month = {11}, pages = {1-8}, abstract = {Current road transportation systems throughout the European Union suffer from severe congestion problems. A solution can be to move towards a Personal Aerial Transportation System, in which vehicles would also have vertical space at their disposal. In the myCopter project, funded by the European Union under the 7th Framework Programme, the viability of such a system will be investigated. It is argued that this should be done by taking into account the required operational infrastructure, instead of starting with the design of a vehicle. By investigating human-machine interfaces and training, automation technologies, and socio-economic impact, the myCopter project aims to provide a basis for a transportation system based on Personal Aerial Vehicles. In this paper, an outline of the project is given. Early research results are detailed and provide a basis for the remainder of the project.}, file_url = {fileadmin/user_upload/files/publications/2011/HeliWorld-2011-Nieuwenhuizen.pdf}, web_url = {http://www.airtec.aero/index.php?id=55}, event_name = {3rd International HELI World Conference 2011 "Helicopter Technologies and Operations" (HeliWorld 2011)}, event_place = {Frankfurt a.M.}, state = {published}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, Jump M, Perfect P, White MD, Padfield GD, Floreano D, Schill F, Zufferey J-C, Fua P, Bouabdallah S, Siegwart R, Meyer S, Schippl J, Decker M, Gursky B, H\"ofinger M and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ VenrooijMvABM2011, title = {Cancelling biodynamic feedthrough requires a subject and task dependent approach}, year = {2011}, month = {10}, pages = {1670-1675}, abstract = {Vehicle accelerations may feed through the human body, causing involuntary limb motions which may lead to involuntary control inputs. This phenomenon is called biodynamic feedthrough (BDFT). Signal cancellation is a possible way of mitigating biodynamic feedthrough. It makes use of a BDFT model to estimate the involuntary control inputs. The BDFT effects are removed by subtracting the modeled estimate of the involuntary control input from the total control signal, containing both voluntary and involuntary components. The success of signal cancellation hinges on the accuracy of the BDFT model used. In this study the potential of signal cancellation is studied by making use of a method called optimal signal cancellation. Here, an identified BDFT model is used off-line to generate an estimate of the involuntary control inputs based on the accelerations present. Results show that reliable signal cancellation requires BDFT models that are both subject and task dependent. The task dependency is of particular importance: failing to adapt the model to changes in the operator's neuromuscular dynamics dramatically decreases the quality of cancellation and can even lead to an increase in unwanted effects. As a reliable and fast on-line identification method of the neuromuscular dynamics of the human operator currently does not exist, real-time signal cancellation is currently not feasible.}, web_url = {http://www.smc2011.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Systems, Man and Cybernetics (SMC 2011)}, event_place = {Anchorage, AK, USA}, state = {published}, ISBN = {978-1-4577-0652-3}, DOI = {10.1109/ICSMC.2011.6083911}, author = {Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}, Mulder M, van Paassen MM, Abbink DA, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mulder M} } @Inproceedings{ SonCKB2011, title = {Haptic Feedback Cues Can Improve Human Perceptual Awareness in Multi-Robots Teleoperation}, year = {2011}, month = {10}, pages = {1323-1328}, abstract = {The availability of additional force cues in haptic devices are often expected to improve control performance, over conditions that only provide visual feedback. However, there is little empirical evidence to show this to be true for the teleoperation control of remote vehicles (i.e., multiple unmanned aerial vehicles (UAVs)). In this paper, we show that force cues can increase one's sensitivity in discerning the presence of obstacles in the remote multi-UAVs' environment. Significant benefits, relative to a purely visual scenario, were achieved only when force cues were sufficiently amplified by large gains. In addition, force cues tended to provide stronger benefits when they were based on the UAVs' velocity information.}, web_url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6106130}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {11th International Conference on Control, Automations and Systems (ICCAS 2011)}, event_place = {Gyeonggi-do, Korea}, state = {published}, ISBN = {978-1-4577-0835-0}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Chuang L{chuang}{Department Human Perception, Cognition and Action}, Kim J{junsukkim}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ LayherTSBCN2011, title = {Social Signal Processing in Companion Systems: Challenges Ahead}, year = {2011}, month = {10}, pages = {239}, abstract = {Companion technologies aim at developing sustained long-term relationships by employing emotional, nonverbal communication skills and empathy. One of the main challenges is to equip such companions with human-like abilities to reliably detect and analyze social signals. In this proposal, we focus our investigation on the modeling of visual processing mechanisms, since evidence in literature suggests that nonverbal interaction plays a key role in steering, controlling and maintaining social interaction between humans. We seek to transfer fragments of this competence to the domain of human computer interaction. Some core computational mechanisms of extracting and analyzing nonverbal signals are presented, enabling virtual agents to create socially competent response behaviors.}, file_url = {fileadmin/user_upload/files/publications/2011/Informatik-2011-Layher.pdf}, web_url = {http://www.user.tu-berlin.de/komm/CD/html/ws603.html}, editor = {Heiss , H.-U. , P. Pepper, H. Schlingloff, J. Schneider}, publisher = {Gesellschaft für Informatik}, address = {Bonn, Germany}, booktitle = {Informatik 2011: Informatik schafft Communities}, event_name = {Workshop on "Companion-Systeme und Mensch-Companion-Interaktion"}, event_place = {Berlin, Germany}, state = {published}, ISBN = {978-3-88579-286-4}, author = {Layher G, Neumann H, Scherer S, Tschechne S, Brosch T and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ FranchiMBR2011, title = {Bilateral teleoperation of multiple UAVs with decentralized bearing-only formation control}, year = {2011}, month = {9}, pages = {2215-2222}, abstract = {We present a decentralized system for the bilateral teleoperation of groups of UAVs which only relies on relative bearing measurements, i.e., without the need of distance information or global localization. The properties of a 3D bearing-formation are analyzed, and a minimal set of bearings needed for its definition is provided. We also design a novel decentralized formation control almost globally convergent and able to maintain bounded and non-vanishing inter-distances among the agents despite the absence of direct distance measurements. Furthermore, we develop a multi-master/ multi-slave teleoperation setup in order to control the overall behavior of the group and to convey to the human operator suitable force cues, while ensuring stability in presence of delays and packet losses over the master-slave communication channel. The theoretical framework is validated by means of extensive human/hardware in-the-loop simulations using two force-feedback devices and a group of quadrotors.}, file_url = {fileadmin/user_upload/files/publications/2011/IROS-2011-Franchi.pdf}, web_url = {http://www.iros2011.org/}, editor = {Amato, N.M.}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011)}, event_place = {San Francisco, CA, USA}, state = {published}, ISBN = {978-1-61284-454-1}, DOI = {10.1109/IROS.2011.6094525}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}, Masone C{masone}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6845, title = {Evaluation of Direct and Indirect Haptic Aiding in an Obstacle Avoidance Task for Tele-Operated Systems}, journal = {Proceedings of the 18th World Congress of the International Federation of Automatic Control (IFAC 2011)}, year = {2011}, month = {9}, pages = {6472-6477}, abstract = {The sense of telepresence is very important in teleoperation environments in which the operator is physically separated from the vehicle. It appears reasonable, and it has already been shown in the literature, that extending the visual feedback with force feedback is able to complement the visual information (when missing or limited) through the sense of touch and allows the operator to better perceive information from the remote environment and its constraints, hopefully preventing dangerous collisions. This paper focuses on a novel concept of haptic cueing for an airborne obstacle avoidance task; the novel cueing algorithm was designed in order to appear “natural” to the operator, and to improve the human-machine interface without directly acting on the actual aircraft commands. An experimental evaluation of two different Haptic aiding concepts for obstacle avoidance is presented. An existing and widely used approach, belonging to what we called the Direct Haptic Aid (DHA) class, and a novel one based on the Indirect Haptic Aid (IHA) class. The two haptic aids were compared with a baseline condition in which no haptic force was associated to the obstacles. Test results show that a net improvement in terms of performance (i.e. the number of collisions) is provided by employing the IHA haptic cue instead of both the DHA haptic cue and the visual cue only. Most participants of the experiment reported the strongest force feeling, the most necessary effort and also the most helpful sensation with DHA and IHA conditions with respect to the baseline condition. This paper shows that the IHA philosophy is a valid alternative to the other commonly used, and published in the scientific literature, approaches which fall in the DHA category.}, file_url = {fileadmin/user_upload/files/publications/2011/IFAC-2011-Alaimo.pdf}, web_url = {http://www.ifac2011.org/}, editor = {Bittanti, S. , A. Cenedese, S. Zampieri}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {18th World Congress of the International Federation of Automatic Control (IFAC WC 2011)}, event_place = {Milano, Italy}, state = {published}, ISBN = {978-1-618-39122-3}, DOI = {10.3182/20110828-6-IT-1002.02790}, author = {Alaimo SMC{alaimo}{Department Human Perception, Cognition and Action}, Pollini L{lpollini}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ RobuffoGiordanoFSB2011_2, title = {Experiments of passivity-based bilateral aerial teleoperation of a group of UAVs with decentralized velocity synchronization}, year = {2011}, month = {9}, pages = {163-170}, abstract = {In this paper, we present an experimental validation of a novel decentralized passivity-based control strategy for teleoperating a group of Unmanned Aerial Vehicles (UAVs): the slave side, consisting of the UAVs, is endowed with large group autonomy by allowing time-varying topology and interrobot/obstacle collision avoidance. The master side, represented by a human operator, controls the group motion and receives suitable force feedback cues informing her/him about the remote slave motion status. Passivity theory is exploited for guaranteeing stability of the slave side and of the overall teleoperation channel. Results of experiments involving the use of 4 quadcopters are reported and discussed, confirming the soundness of the paper theoretical claims.}, file_url = {fileadmin/user_upload/files/publications/2011/2011k-RobFraSecBue-preprint.pdf}, web_url = {http://www.iros2011.org/}, editor = {Amato, N.M.}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011)}, event_place = {San Francisco, CA, USA}, state = {published}, ISBN = {978-1-61284-454-1}, DOI = {10.1109/IROS.2011.6094895}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Secchi C and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ EngelBHC2011, title = {Image Retrieval with Semantic Sketches}, year = {2011}, month = {9}, pages = {412-425}, abstract = {With increasingly large image databases, searching in them becomes an ever more difficult endeavor. Consequently, there is a need for advanced tools for image retrieval in a webscale context. Searching by tags becomes intractable in such scenarios as large numbers of images will correspond to queries such as “car and house and street”. We present a novel approach that allows a user to search for images based on semantic sketches that describe the desired composition of the image. Our system operates on images with labels for a few high-level object categories, allowing us to search very fast with a minimal memory footprint. We employ a structure similar to random decision forests which avails a data-driven partitioning of the image space providing a search in logarithmic time with respect to the number of images. This makes our system applicable for large scale image search problems. We performed a user study that demonstrates the validity and usability of our approach.}, web_url = {http://interact2011.org/}, editor = {Campos, P. , N. Graham, J. Jorge, N. Nunes, P. Palanque, M. Winckler}, publisher = {Springer}, address = {Berlin, Germany}, booktitle = {Human-Computer Interaction: INTERACT 2011}, event_name = {13th IFIP TC13 Conference on Human-Computer Interaction}, event_place = {Lisboa, Portugal}, state = {published}, ISBN = {978-3-642-23774-4}, DOI = {10.1007/978-3-642-23774-4_35}, author = {Engel D{engel}{Department Human Perception, Cognition and Action}, Herdtweck C{grueschaan}{Department Human Perception, Cognition and Action}, Browatzki B{browatbn}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ SonCFKLLBR2011, title = {Measuring an Operator's Maneuverability Performance in the Haptic Teleoperation of Multiple Robots}, year = {2011}, month = {9}, pages = {3039-3046}, abstract = {In this paper, we investigate the maneuverability performance of human teleoperators on multi-robots. First, we propose that maneuverability performance can be assessed by a frequency response function that jointly considers the input force of the operator and the position errors of the multi-robot system that is being maneuvered. Doing so allows us to evaluate maneuverability performance in terms of the human teleoperator's interaction with the controlled system. This allowed us to effectively determine the suitability of different haptic cue algorithms in improving teleoperation maneuverability. Performance metrics based on the human teleoperator's frequency response function indicate that maneuverability performance is best supported by a haptic feedback algorithm which is based on an obstacle avoidance force.}, file_url = {fileadmin/user_upload/files/publications/2011/IROS-2011-Son.pdf}, web_url = {http://www.iros2011.org/}, editor = {Amato, N.M.}, publisher = {IEEE}, address = {Piscatawy, NJ, USA}, event_name = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011)}, event_place = {San Francisco, CA, USA}, state = {published}, ISBN = {978-1-61284-454-1}, DOI = {10.1109/IROS.2011.6048185}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Chuang LL{chuang}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Kim J{junsukkim}{Department Human Perception, Cognition and Action}, Lee D, Lee S-W, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ NolanBWFBR2011_3, title = {Motion P3 demonstrates neural nature of motion ERPs}, year = {2011}, month = {9}, pages = {3884-3887}, abstract = {The technical challenges of recording electroencephalographic (EEG) data during motion are considerable, but would enable the possibility of investigating neural function associated with balance, motor function and motion perception. The challenges include finding a reliable method of motion stimulus reproduction, removing artifacts, and ensuring that the recordings retain sufficient EEG signal for proper interpretation. This study details the use of the P3 waveform to validate the concept of motion-based EEG data, and discusses some potential future uses in experimental and clinical settings.}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6090965}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2011)}, event_place = {Boston, MA, USA}, state = {published}, ISBN = {978-1-4244-4121-1}, DOI = {10.1109/IEMBS.2011.6090965}, author = {Nolan H, Butler JS{butler}{Department Human Perception, Cognition and Action}, Whelan R, Foxe JJ, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Reilly RB} } @Inproceedings{ StegagnoCFO2011, title = {Mutual localization using anonymous bearing measurements}, year = {2011}, month = {9}, pages = {469-474}, abstract = {This paper addresses the problem of mutual localization in multi-robot systems in presence of anonymous (i.e., without the identity information) bearing-only measurements. The solution of this problem is relevant for the design and implementation of any decentralized multi-robot algorithm/control. A novel algorithm for probabilistic multiple registration of these measurements is presented, where no global localization, distances, or identity are used. With respect to more conventional solutions that could be conceived on the basis of the current literature, our method is theoretically suitable for tasks requiring frequent, many-to-many encounters among agents (e.g., formation control, cooperative exploration, multiple-view environment sensing). An extensive experimental study validates our method and compares it with the full-informative case of bearing-plus-distance measurements. The results show that the proposed localization system exhibits an accuracy commensurate to our previous method [1] which uses bearing-plus-distance information.}, file_url = {fileadmin/user_upload/files/publications/2011/IROS-2011-Stegnano.pdf}, web_url = {http://www.iros2011.org/}, editor = {Amato, N.M.}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011)}, event_place = {San Francisco, CA, USA}, state = {published}, ISBN = {978-1-61284-454-1}, DOI = {10.1109/IROS.2011.6094635}, author = {Stegagno P, Cognetti M{mcognetti}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action} and Oriolo G} } @Inproceedings{ CaniardBMLT2011, title = {Active control does not eliminate motion-induced illusory displacement}, year = {2011}, month = {8}, pages = {101-108}, abstract = {When the sine-wave grating of a Gabor patch drifts to the left or right, the perceived position of the entire object is shifted in the direction of local motion. In the current paper, we explored whether active control of the physical position of the patch can overcome such motion induced illusory displacement. We created a simple computer game and asked participants to continuously guide a Gabor patch along a randomly curving path. When the grating inside the Gabor patch was stationary, participants could perform this task without error. When the grating drifted to either left or right, we observed systematic errors consistent with previous reports of motion-induced illusory displacement. Specifically, when the grating drifted to the right, participants adjusted the global position of the patch to the left of the target line, and when it drifted to the left, errors were to the right of the line. The magnitude of the errors was consistent with previously reported perceptual judgements for centrally presented items, and scaled systematically with the speed of local drift. Importantly, we found no evidence that participants could adapt or compensate for illusory displacement given active control of the target. The current findings could have important implications for interface design, suggesting that local dynamic components of a display could affect perception and action within the more global application environment.}, file_url = {fileadmin/user_upload/files/publications/2011/APGV-2011-caniard.pdf}, web_url = {http://www.apgv.org/archive/apgv11/}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {8th Symposium on Applied Perception in Graphics and Visualization (APGV 2011)}, event_place = {Toulouse, France}, state = {published}, ISBN = {978-1-4503-0889-2}, DOI = {10.1145/2077451.2077470}, author = {Caniard F{franck}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Mamassian P{pascal}{Department Human Perception, Cognition and Action}, Lee S-W and Thornton IM{ian}{Department Human Perception, Cognition and Action}} } @Inproceedings{ AlaimoPB2011_2, title = {Admittance-Based Bilateral Teleoperation with Time Delay for an Unmanned Aerial Vehicle involved in an Obstacle Avoidance Task}, year = {2011}, month = {8}, pages = {19-37}, abstract = {The paper focuses on the implementation of an admittance based control scheme in a bilateral teleoperation set-up for an Unmanned Aerial Vehicle (UAV) under time delay. The goal of this study is to assess and improve the stability characteristics of the bilateral teleoperator. Computer simulations were conducted to evaluate the effectiveness of the admittance-based control scheme. A commercial impedance-like haptic device was chosen to simulate the control stick: the master device. The slave system is constituted by the dynamics of the aircraft under control; in order to maximize the pilot attention on its task, only the lateral aircraft dynamics was considered. A virtual environment was displayed during the experiments to produce the visual cues. In order to evaluate the system, we prepared a control task where the aircraft had to be flown in a virtual urban canyon with buildings placed irregularly (non Manhattan-like) along the desired path by avoiding the collisions with them. A repulsive force field was associated to the obstacles and a force was sent back to the operator through the communication link. A compensator capable of flying autonomously the aircraft through the buildings with satisfactory performance was designed first using linear techniques then the haptic augmentation system was derived from the compensator by splitting it in two parts: the actual haptic cueing for the pilot and the simulated the pilot effort. The latter component was used only for the preliminary assessment of the system and was removed in simulations where a real pilot operated the stick (the master device). Experimental results and analytical motivations as well have shown that a haptic force which is simply proportional to the distance from the obstacles cannot stabilize the system: a relevant anticipatory effect or phase lead (as the derivative effect of standard industrial controllers) is needed. In order to manage the degradation of performance and overall stability when a delay is present in the communication paths, an admittance-based controller was designed together with an observer for the force generated by the human operator on the stick. The admittance-based Force Position teleoperation scheme was shown by simulations and tests with real pilots to improve the performance of the system under consideration.}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2011-6243}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference 2011}, event_place = {Portland, OR, USA}, state = {published}, ISBN = {978-1-62410-154-0}, DOI = {10.2514/6.2011-6243}, author = {Alaimo S{alaimo}{Department Human Perception, Cognition and Action}, Pollini L and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ AlaimoPB2011, title = {Experiments of Direct and Indirect Haptic Aiding for Remotely Piloted Vehicles with a Mixed Wind Gust Rejection/Obstacle Avoidance Task}, year = {2011}, month = {8}, pages = {732-749}, abstract = {This paper focuses on a novel concept of haptic cueing developed in order to optimize the performance of an Unmanned Aerial Vehicle (UAV) teleoperator and to improve the human-machine interfaces in a mixed obstacle avoidance/wind gust rejection task. It presents an experimental evaluation of two different Haptic aiding concepts: one based on what we called Direct Haptic Aiding (DHA) approach, and a novel one based on the Indirect Haptic Aiding (IHA) approach. The two haptic aids were compared with a baseline condition in which no haptic force was associated to the obstacles (NoEF condition). It will be shown that IHA-based approach definitely improves the pilots¡¯ performance with respect to the other approaches. A significant difference in performance (i.e. the number of collisions) was noticed between IHA and both DHA and NoEF conditions. The goal of this paper is to show that the IHA philosophy is a valid alternative to the other commonly used, and published in the scientific literature, approaches which fall in the DHA category.}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2011-6242}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference}, event_place = {Portland, OR, USA}, state = {published}, ISBN = {978-1-62410-154-0}, DOI = {10.2514/6.2011-6242}, author = {Alaimo S{alaimo}{Department Human Perception, Cognition and Action}, Pollini L, Bresciani JP{bresciani}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ McManusBSdBM2011, title = {The influence of avatar (self and character) animations on distance estimation, object interaction and locomotion in immersive virtual environments}, year = {2011}, month = {8}, pages = {37-44}, abstract = {Humans have been shown to perceive and perform actions differently in immersive virtual environments (VEs) as compared to the real world. Immersive VEs often lack the presence of virtual characters; users are rarely presented with a representation of their own body and have little to no experience with other human avatars/characters. However, virtual characters and avatars are more often being used in immersive VEs. In a two-phase experiment, we investigated the impact of seeing an animated character or a self-avatar in a head-mounted display VE on task performance. In particular, we examined performance on three different behavioral tasks in the VE. In a learning phase, participants either saw a character animation or an animation of a cone. In the task performance phase, we varied whether participants saw a co-located animated self-avatar. Participants performed a distance estimation, an object interaction and a stepping stone locomotion task within the VE. We find no impact of a character animation or a self-avatar on distance estimates. We find that both the animation and the self-avatar influenced task performance which involved interaction with elements in the environment; the object interaction and the stepping stone tasks. Overall the participants performed the tasks faster and more accurately when they either had a self-avatar or saw a character animation. The results suggest that including character animations or self-avatars before or during task execution is beneficial to performance on some common interaction tasks within the VE. Finally, we see that in all cases (even without seeing a character or self-avatar animation) participants learned to perform the tasks more quickly and/or more accurately over time.}, web_url = {http://www.apgv.org/archive/apgv11/}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {8th Symposium on Applied Perception in Graphics and Visualization (APGV 2011)}, event_place = {Toulouse, France}, state = {published}, ISBN = {978-1-4503-0889-2}, DOI = {10.1145/2077451.2077458}, author = {McManus EA, Bodenheimer B, Streuber S{stst}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Inproceedings{ LeyrerLBKM2011, title = {The influence of eye height and avatars on egocentric distance estimates in immersive virtual environments}, year = {2011}, month = {8}, pages = {67-74}, abstract = {It is well known that eye height is an important visual cue in the perception of apparent sizes and affordances in virtual environments. However, the influence of visual eye height on egocentric distances in virtual environments has received less attention. To explore this influence, we conducted an experiment where we manipulated the virtual eye height of the user in a head-mounted display virtual environment. As a measurement we asked the participants to verbally judge egocentric distances and to give verbal estimates of the dimensions of the virtual room. In addition, we provided the participants a self-animated avatar to investigate if this virtual self-representation has an impact on the accuracy of verbal distance judgments, as recently evidenced for distance judgments accessed with an action-based measure. When controlled for ownership, the avatar had a significant influence on the verbal estimates of egocentric distances as found in previous research. Interestingly, we found that the manipulation of eye height has a significant influence on the verbal estimates of both egocentric distances and the dimensions of the room. We discuss the implications which these research results have on those interested in space perception in both immersive virtual environments and the real world.}, web_url = {http://www.apgv.org/archive/apgv11/}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {8th Symposium on Applied Perception in Graphics and Visualization (APGV 2011)}, event_place = {Toulouse, France}, state = {published}, ISBN = {978-1-4503-0889-2}, DOI = {10.1145/2077451.2077464}, author = {Leyrer M{leyrer}{Department Human Perception, Cognition and Action}, Linkenauger SA{sally}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Kloos U and Mohler B{mohler}{Department Human Perception, Cognition and Action}} } @Inproceedings{ NieuwenhuizenMvB2011, title = {The Influence of Motion System Characteristics on Pilot Control Behaviour}, year = {2011}, month = {8}, pages = {204-218}, abstract = {Full flight simulators are widely being used for training of pilots as they provide a cost-effective alternative over aircraft. However, a compromise must always be found between the amount of motion cueing that needs to be presented to the pilot for effective training and the available workspace of the simulator. In literature, contradictory reports are found on the effect of motion cues on pilot performance in the simulator. In this paper, the results are presented of an experiment in which the influence of the quality of motion systems was investigated. A model of the MPI Stewart platform was simulated on the SIMONA Research Simulator and the motion system characteristics of both simulators were varied systematically to determine their effects on pilot control behaviour. The time delay and noise characteristics of the simulators did not have an effect in this experimental task. However, it was found that the bandwidth of the motion system had a significant effect on performance and control behaviour. Results indicate that the motion cues were barely used at all in conditions with a low bandwidth, and that participants relied on the visual cues to generate lead needed in their control task.}, file_url = {fileadmin/user_upload/files/publications/2011/AIAA-2011-6321-Nieuwenhuizen.pdf}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2011-6321}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference 2011}, event_place = {Portland, OR, USA}, state = {published}, ISBN = {978-1-62410-154-0}, DOI = {10.2514/6.2011-6321}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, Mulder M, van Paassen MM and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ Franchi2011, title = {Decentralized Bilateral Aerial Teleoperation of Multiple UAVs - Part II: a Top-down Perspective}, year = {2011}, month = {7}, pages = {1-12}, abstract = {This talk will present some recent theoretical and experimental results in the relatively new topic of Bilateral Aerial Teleoperation of Multiple UAVs. In this non-conventional teleoperation field a human operator partially controls the behavior of a semi-autonomous swarm of UAVs by means of one or more haptic interfaces, and receives back a force cue which is informative both of the swarm tracking performance and of some relevant properties of the surrounding environment (e.g., presence of obstacles or other threats). This kind of systems are designed in order to enhance the telepresence of the operator and the quality of the human robot interaction, especially when applied to practical scenarios, like search and rescue, surveillance, exploration and mapping. In particular, the focus of the talk will be on the design of a stable bilateral interconnection between the user and the swarm of UAVs, considered as a deformable object with a given shape (top-down approach) to be achieved with suitable formation control algorithms using either distance-only or bearing-only sensors.}, file_url = {fileadmin/user_upload/files/publications/2011/RSS-2011-Workshop-Franchi.pdf}, web_url = {http://mrsl.grasp.upenn.edu/rss2011workshop/Schedule/}, event_name = {RSS 2011 Workshop “3D Exploration, Mapping, and Surveillance with Aerial Robots”}, event_place = {Los Angeles, CA, USA}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ RobuffoGiordano2011_2, title = {Decentralized Bilateral Aerial Teleoperation of Multiple UAVs – Part I: a Bottom-up Perspective}, year = {2011}, month = {7}, pages = {1-11}, abstract = {In this talk, we will review some recent advancements in the field of Aerial Teleoperation, i.e., how to bilaterally couple a single human operator with a remote fleet of semiautonomous UAVs which 1) must keep some spatial formation and avoid inter- and obstacle- collisions, and 2) must collectively follow the human commands. The emphasis will be placed on the modeling and control tools needed for establishing such a non-conventional bilateral channel: in particular, we will study how to render the multi-UAV “slave side” a passive system w.r.t. the environment, and how to still enforce global connectivity maintenance despite limited sensing and loss of visibility because of occlusions.}, file_url = {fileadmin/user_upload/files/publications/2011/RSS-2011-Workshop-Robuffo-1.pdf}, web_url = {http://mrsl.grasp.upenn.edu/rss2011workshop/Schedule/}, event_name = {RSS 2011 Workshop “3D Exploration, Mapping, and Surveillance with Aerial Robots”}, event_place = {Los Angeles, CA, USA}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ HensonMBM2011, title = {When do we integrate spatial information acquired by walking through environmental spaces?}, year = {2011}, month = {7}, pages = {2764-2769}, abstract = {The present study examined whether spatial information of a novel environment was integrated within a reference frame during initial learning, or only later when required for pointing to other targets. Twenty-two participants repeatedly walked through a multi-corridor virtual environment, presented via a head-mounted display. At several stages within the learning process they were teleported to locations along the route and asked to self-localize and point to other locations. Pointing was faster during later tests as well as for closer targets, both of which might require less integration. Participants tested only after extended exposure (late pointers) took longer than participants who had received testing interspersed throughout the same amount of exposure (early pointers). Pointing latency did not differ between groups when comparing performance on their first pointing test, despite vastly different exposure. These results are inconsistent with the assumption that participants already integrated spatial information within a single reference frame during learning and simply accessed this information during testing. Rather, spatial integration is a time consuming process which is not necessarily undertaken if not required.}, file_url = {fileadmin/user_upload/files/publications/2011/CogSci-2011-Henson.pdf}, web_url = {http://csjarchive.cogsci.rpi.edu/Proceedings/2011/index.html}, editor = {Carlson, L. , C. Hoelscher, T.F. Shipley}, publisher = {Cognitive Science Society}, address = {Austin, TX, USA}, booktitle = {Expanding the Space of Cognitive Science}, event_name = {33rd Annual Meeting of the Cognitive Science Society (CogSci 2011)}, event_place = {Boston, MA, USA}, state = {published}, author = {Henson A{ahenson}{Department Human Perception, Cognition and Action}, Mallot HA{ham}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Meilinger T{meilinger}{Department Human Perception, Cognition and Action}} } @Inproceedings{ SonKCFRLB2011, title = {An Evaluation of Haptic Cues on the Tele-Operator's Perceptual Awareness of Multiple UAVs' Environments}, year = {2011}, month = {6}, pages = {149-154}, abstract = {The use of multiple unmanned aerial vehicles (UAVs) is increasingly being incorporated into a wide range of teleoperation applications. To date, relevant research has largely been focused on the development of appropriate control schemes. In this paper, we extend previous research by investigating how control performance could be improved by providing the teleoperator with haptic feedback cues. First, we describe a control scheme that allows a teleoperator to manipulate the flight of multiple UAVs in a remote environment. Next, we present three designs of haptic cue feedback that could increase the teleoperator's environmental awareness of such a remote environment. These cues are based on the UAVs' i) velocity information, ii) proximity to obstacles, and iii) a combination of these two sources of information. Finally, we present an experimental evaluation of these haptic cue designs. Our evaluation is based on the teleoperator's perceptual sensitivity to the physical environment inhabited by the multiple UAVs. We conclude that a teleoperator's perceptual sensitivity is best served by haptic feedback cues that are based on the velocity information of multiple UAVs.}, file_url = {fileadmin/user_upload/files/publications/2011/WHC-2011-Son.pdf}, web_url = {http://www.haptics2011.org/en/}, editor = {Jones, L. , M. Harders, Y. Yokokohji}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE 2011 World Haptics Conference (WHC 2011)}, event_place = {Istanbul, Turkey}, state = {published}, ISBN = {978-1-4577-0299-0}, DOI = {10.1109/WHC.2011.5945477}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Kim J{junsukkim}{Department Human Perception, Cognition and Action}, Chuang LL{chuang}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Lee D and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ RobuffoGiordanoFSB2011, title = {Bilateral Teleoperation of Groups of UAVs with Decentralized Connectivity Maintenance}, year = {2011}, month = {6}, pages = {273-280}, abstract = {In this paper, we present a decentralized passivity-based control strategy for the bilateral teleoperation of a group of Unmanned Aerial Vehicles (UAVs). The human operator at the master side can command the group motion and receive suitable force cues informative about the remote environment. By properly controlling the energy exchanged within the slave side (the UAV group), we guarantee that the connectivity of the group is preserved and we prevent inter-agent and obstacle collisions. At the same time, we allow the behavior of the UAVs to be as flexible as possible with arbitrary split and join maneuvers. The results of the paper are validated by means of human/hardware-in-the-loop (HHIL) simulations.}, file_url = {fileadmin/user_upload/files/publications/2011/RSS-2011-Robuffo.pdf}, web_url = {http://www.roboticsproceedings.org/rss07/p13.html}, editor = {Durrant-Whyte, H.F. , N. Roy, P. Abbeel}, publisher = {MIT Press}, address = {Cambridge, MA, USA}, booktitle = {Robotics: Science and Systems VII}, event_name = {2011 Robotics: Science and Systems Conference}, event_place = {Los Angeles, CA, USA}, state = {published}, ISBN = {978-0-262-51779-9}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Secchi C and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ GaissertW2011, title = {Integrating Visual and Haptic Shape Information to Form a Multimodal Perceptual Space}, year = {2011}, month = {6}, pages = {451-456}, abstract = {In this study we want to address the question to what extent the visual and the haptic modalities contribute to the final formation of a complex multisensory perceptual space. By varying three shape parameters a physical shape space of shell-like objects was generated. Participants were allowed to either see or touch the objects or use both senses to explore the objects. Similarity ratings were performed and analyzed using multidimensional scaling (MDS) techniques. By comparing the unimodal perceptual spaces to the multimodal perceptual space we tried to resolve the impact of the visual and the haptic modalities on the combined percept. We found that neither the visual nor the haptic modality dominated the final percept, but rather that the two modalities contributed to the combined percept almost equally. To investigate to which degree these results are transferrable to natural objects, we performed the same visual, haptic, and visuo-haptic similarity ratings and multidimensional scaling analyses using a set of natural sea shells. Again, we found almost equal contributions of the visual and the haptic modalities to the combined percept. Our results suggest that multisensory perceptual spaces are based on a complex combination of object information gathered by different senses.}, web_url = {http://www.haptics2011.org/en/}, editor = {Jones, L.A. , M. Harders, Y. Yokokohji}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE World Haptics Conference (WHC 2011)}, event_place = {Istanbul, Turkey}, state = {published}, ISBN = {978-1-4577-0299-0}, DOI = {10.1109/WHC.2011.5945528}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Inproceedings{ JumpPWFZSSBDSHNB2011, title = {myCopter: Enabling Technologies for Personal Air Transport Systems}, year = {2011}, month = {6}, pages = {1-15}, abstract = {This paper describes the European Commission Framework 7 funded project myCopter (2011-2014). The project is still at an early stage so the paper starts with the current transportation issues faced by developed countries and describes a means to solve them through the use of personal aerial transportation. The concept of personal air vehicles (PAV) is briefly reviewed and how this project intends to tackle the problem from a different perspective described. It is argued that the key reason that many PAV concepts have failed is because the operational infrastructure and socio-economic issues have not been properly addressed; rather, the start point has been the design of the vehicle itself. Some of the key aspects that would make a personal aerial transport system (PATS) viable include the required infrastructure and associated technologies, the skill levels and machine interfaces needed by the occupant or pilot and the views of society as a whole on the acceptability of such a proposition. The myCopter project will use these areas to explore the viability of PAVs within a PATS. The paper provides an overview of the project structure, the roles of the partners, and hence the available research resources, and some of the early thinking on each of the key project topic areas.}, file_url = {fileadmin/user_upload/files/publications/2011/RAeS-Spring-2011-Nieuwenhuizen.pdf}, web_url = {http://www.aerosocietychannel.com/events/2011/03/future-rotorcraft/}, publisher = {Royal Aeronautical Society}, address = {London, UK}, booktitle = {The Future Rotorcraft: Enabling Capability through the Application of Technology}, event_name = {Royal Aeronautical Society Conference on the Future Rotorcraft (RAeS 2011)}, event_place = {London, UK}, state = {published}, ISBN = {1-85768-274-2}, author = {Jump M, Padfield GD, White MD, Fua P, Zufferey J-C, Schill F, Siegwart R, Bouabdallah S, Decker M, Schippl J, H\"ofinger M, Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ EngelC2011_2, title = {Pedestrian Detectability: Predicting Human Perception Performance with Machine Vision}, year = {2011}, month = {6}, pages = {429-435}, abstract = {How likely is it that a driver notices a person standing on the side of the road? In this paper we introduce the concept of pedestrian detectability. It is a measure of how probable it is that a human observer perceives pedestrians in an image. We acquire a dataset of pedestrians with their associated detectabilities in a rapid detection experiment using images of street scenes. On this dataset we learn a regression function that allows us to predict human detectabilities from an optimized set of image and contextual features. We exploit this function to infer the optimal focus of attention for pedestrian detection. With this combination of human perception and machine vision we propose a method we deem useful for the optimization of Human-Machine-Interfaces in driver assistance systems.}, file_url = {fileadmin/user_upload/files/publications/2011/IV-2011-Engel.pdf}, web_url = {http://www.mrt.uni-karlsruhe.de/iv2011/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE Intelligent Vehicles Symposium (IV 2011)}, event_place = {Baden-Baden, Germany}, state = {published}, ISBN = {978-1-4577-0890-9}, DOI = {10.1109/IVS.2011.5940445}, author = {Engel D{engel}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ FranchiRSSB2011, title = {A Passivity-Based Decentralized Approach for the Bilateral Teleoperation of a Group of UAVs with Switching Topology}, year = {2011}, month = {5}, pages = {898-905}, abstract = {In this paper, a novel distributed control strategy for teleoperating a fleet of Unmanned Aerial Vehicles (UAVs) is proposed. Using passivity based techniques, we allow the behavior of the UAVs to be as flexible as possible with arbitrary split and join decisions while guaranteeing stability of the system. Furthermore, the overall teleoperation system is also made passive and, therefore, characterized by a stable behavior both in free motion and when interacting with unknown passive obstacles. The performance of the system is validated through semi-experiments.}, file_url = {fileadmin/user_upload/files/publications/2011/2011a-FraRobSecSonBue-preprint.pdf}, web_url = {http://www.icra2011.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2011)}, event_place = {Shanghai, China}, state = {published}, ISBN = {978-1-61284-386-5}, DOI = {10.1109/ICRA.2011.5980368}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Secchi C, Son HI{chakurt}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ AlexandrovaRBKTBM2011, title = {Animations of Medical Training Scenarios in Immersive Virtual Environments}, year = {2011}, month = {5}, pages = {9-12}, abstract = {Medical training centers often provide various simulations for students and professionals. Their goal is not only to make trainees practice specific scenarios but also to help them effectively transfer the acquired skills to the real world. Having in mind that virtual environments have already been acknowledged for their potential to improve the medical training process, we propose an approach for rapid generation of animated medical scenarios, which can be used as an additional training tool that fits into the time frame of a semester training program.}, file_url = {fileadmin/user_upload/files/publications/2011/CASA-2011-Alexandrova.pdf}, web_url = {http://www.cad.zju.edu.cn/casa2011/program.html}, editor = {Liu, Y. , A. El Rhalibi, L. Li, M. Zhang, Z. Pan}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {2011 Workshop on Digital Media and Digital Content Management (DMDCM)}, event_place = {Hangzhou, Zhejiang, China}, state = {published}, ISBN = {978-1-4577-0271-6}, DOI = {10.1109/DMDCM.2011.64}, author = {Alexandrova IV{ivelina}{Department Human Perception, Cognition and Action}, Rall M, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, Kloos U, Tullius G, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Inproceedings{ NolanBWFBR2011_2, title = {Electrophysiological source analysis of passive self-motion}, year = {2011}, month = {5}, pages = {53-56}, abstract = {The neural processes underlying perception of motion are relatively unknown. In this study Electroencephalography (EEG) is used to investigate the neural responses to passive self-motion. A Stewart platform was employed to translate subjects forwards and backwards while high-density EEG data was recorded. Modern source modeling methods were combined with classical waveform and topographic analyses to determine the electrophysiological correlates of motion processing.}, web_url = {http://ne2011.embs.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {5th International IEEE/EMBS Conference on Neural Engineering (NER 2011)}, event_place = {Cancun, Mexico}, state = {published}, ISBN = {978-1-4244-4140-2}, DOI = {10.1109/NER.2011.5910487}, author = {Nolan H, Butler JS{butler}{Department Human Perception, Cognition and Action}, Whelan R, Foxe JJ, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Reilly RB} } @Inproceedings{ DoddsMdSB2011, title = {Embodied Interaction in Immersive Virtual Environments with Real Time Self-animated Avatars}, year = {2011}, month = {5}, pages = {132-135}, abstract = {This paper outlines our recent research that is providing users with a 3D avatar representation, and in particular focuses on studies in which the avatar is self-animated in real time. We use full body motion tracking, so when participants move their hands and feet, these movements are mapped onto the avatar. In a recent study (Dodds et al., CASA 2010), we found that a self-animated avatar aided participants in a communication task in a head-mounted display immersive virtual environment (VE). From the perspective of communication, we discovered it was not only important for the person speaking to be self-animated, but also for the person listening to us. Further, we show the potential of immersive VEs for investigating embodied interaction, and highlight possibilities for future research.}, file_url = {fileadmin/user_upload/files/publications/2011/CHI-2011-Dodds.pdf}, web_url = {http://www.antle.iat.sfu.ca/chi2011_EmbodiedWorkshop/}, web_url2 = {http://www.elisevandenhoven.com/publications/antle-chi11wp.pdf}, editor = {Antle A.N. , P. Marshall P, E. Van Den Hoven}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {Workshop Embodied Interaction: Theory and Practice in HCI (CHI 2011)}, event_place = {Vancouver, BC}, state = {published}, author = {Dodds TJ{dodds}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Streuber S{stst}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ LeeFRSB2011, title = {Haptic Teleoperation of Multiple Unmanned Aerial Vehicles over the Internet}, year = {2011}, month = {5}, pages = {1341-1347}, abstract = {We propose a novel haptic teleoperation control framework for multiple unmanned aerial vehicles (UAVs) over the Internet, consisting of the three control layers: 1) UAV control layer, where each UAV is abstracted by, and is controlled to follow the trajectory of, its own kinematic virtual point (VP); 2) VP control layer, which modulates each VP's motion according to the teleoperation commands and local artificial potentials (for inter-VP/VP-obstacle collision avoidance and inter-VP connectivity preservation); and 3) teleoperation layer, through which a remote human user can command all (or some) of the VPs' velocity while haptically perceiving the state of all (or some) of the UAVs over the Internet. Master-passivity/slave-stability and some asymptotic performance measures are proved. Semi-experiment results are presented to validate the theory.}, file_url = {fileadmin/user_upload/files/publications/2011/2011b-LeeFraRobSonBue-preprint.pdf}, web_url = {http://www.icra2011.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2011)}, event_place = {Shanghai, China}, state = {published}, ISBN = {978-1-61284-386-5}, DOI = {10.1109/ICRA.2011.5979993}, author = {Lee D, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Son HI{chakurt}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ MasoneRB2011, title = {Mechanical design and control of the new 7-DOF CyberMotion simulator}, year = {2011}, month = {5}, pages = {4935-4942}, abstract = {This paper describes the mechanical and control design of the new 7-DOF CyberMotion Simulator, a redundant industrial manipulator arm consisting of a standard 6-DOF anthropomorphic manipulator plus an actuated cabin attached to the end-effector. Contrarily to Stewart platforms, an industrial manipulator offers several advantages when used as motion simulator: larger motion envelope, higher dexterity, and possibility to realize any end-effector posture within the workspace. In addition to this, the new actuated cabin acts as an additional joint and provides the needed kinematic redundancy to cope with the robot actuator and joint range constraints, which in general can significantly deteriorate the desired motion cues the robot is reproducing. In particular, we will show that, by suitably exploiting the redundancy better results can be obtained in reproducing sustained acceleration cues, a relevant problem when implementing vehicle simulators.}, web_url = {http://www.icra2011.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA 2011)}, event_place = {Shanghai, China}, state = {published}, ISBN = {978-1-61284-386-5}, DOI = {10.1109/ICRA.2011.5980436}, author = {Masone C{masone}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 7016, title = {Robust Semantic Analysis by Synthesis of 3D Facial Motion}, journal = {Proceedings of the Ninth IEEE International Conference on Automatic Face and Gesture Recognition (FG 2011)}, year = {2011}, month = {3}, pages = {713-719}, abstract = {Rich face models already have a large impact on the fields of computer vision, perception research, as well as computer graphics and animation. Attributes such as descriptiveness, semantics, and intuitive control are desirable properties but hard to achieve. Towards the goal of building such high-quality face models, we present a 3D model-based analysis-by-synthesis approach that is able to parameterize 3D facial surfaces, and that can estimate the state of semantically meaningful components, even from noisy depth data such as that produced by Time-of-Flight (ToF) cameras or devices such as Microsoft Kinect. At the core, we present a specialized 3D morphable model (3DMM) for facial expression analysis and synthesis. In contrast to many other models, our model is derived from a large corpus of localized facial deformations that were recorded as 3D scans from multiple identities. This allows us to analyze unstructured dynamic 3D scan data using a modified Iterative Closest Point model fitting process, followed by a constrained Action Unit model regression, resulting in semantically meaningful facial deformation time courses. We demonstrate the generative capabilities of our 3DMMs for facial surface reconstruction on high and low quality surface data from a ToF camera. The analysis of simultaneous recordings of facial motion using passive stereo and noisy Time-of-Flight camera shows good agreement of the recovered facial semantics.}, web_url = {http://www.fg2011.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {Ninth IEEE International Conference on Automatic Face & Gesture Recognition and Workshops (FG 2011)}, event_place = {Santa Barbara, CA, USA}, state = {published}, ISBN = {978-1-4244-9140-7}, DOI = {10.1109/FG.2011.5771336}, author = {Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ NethSEKBM2011, title = {Velocity-Dependent Dynamic Curvature Gain for Redirected Walking}, year = {2011}, month = {3}, pages = {151-158}, abstract = {The aim of Redirected Walking (RDW) is to redirect a person along their path of travel in a Virtual Environment (VE) in order to increase the virtual space that can be explored in a given tracked area. Among other techniques, the user is redirected on a curved real-world path while visually walking straight in the VE (curvature gain). In this paper, we describe two experiments we conducted to test and extend RDW techniques. In Experiment 1, we measured the effect of walking speed on the detection threshold for curvature of the walking path. In a head-mounted display (HMD) VE, we found a decreased sensitivity for curvature for the slowest walking speed. When participants walked at 0.75 m/s, their detection threshold was approximately 0.1m-1 (radius of approximately 10m). In contrast, for faster walking speeds (>;1.0m/s), we found a significantly lower detection threshold of approximately 0.036m-1 (radius of approximately 27m). In Experiment 2, we implemented many well known redirection techniques into one dynamic RDW application. We integrated a large virtual city model and investigated RDW for free exploration. Further, we implemented a dynamic RDW controller which made use of the results from Experiment 1 by dynamically adjusting the applied curvature gain depending on the actual walking velocity of the user. In addition, we investigated the possible role of avatars to slow the users down or make them rotate their heads while exploring. Both the dynamic curvature gain controller and the avatar controller were evaluated in Experiment 2. We measured the average distance that was walked before reaching the boundaries of the tracked area. The mean walked distance was significantly larger in the condition where the dynamic gain controller was applied. This distance increased from approximately 15m for static gains to approximately 22m for dynamic gains. This did not come at the cost of an increase in simulator sickness. Applying the avatar cont roller did reveal an effect on walking distance or simulator sickness.}, file_url = {fileadmin/user_upload/files/publications/2011/VR-2011-Neth.pdf}, web_url = {http://conferences.computer.org/vr/2011/}, editor = {Hirose, M. , B. Lok, A. Majumder, D. Schmalstieg}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE Virtual Reality Conference (VR 2011)}, event_place = {Singapore}, state = {published}, ISBN = {978-1-4577-0039-2}, DOI = {10.1109/VR.2011.5759454}, author = {Neth C{neth}{Department Human Perception, Cognition and Action}, Souman JL{souman}{Department Human Perception, Cognition and Action}, Engel D{engel}{Department Human Perception, Cognition and Action}, Kloos U, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Inbook{ ErnstDM2011, title = {Multisensory perception: from integration to remapping}, year = {2011}, month = {10}, pages = {225-250}, abstract = {The brain receives information about the environment from all the sensory modalities, including vision, touch and audition. To efficiently interact with the environment, this information must eventually converge in the brain in order to form a reliable and accurate multimodal percept. This process is often complicated by the existence of noise at every level of signal processing, which makes the sensory information derived from the world imprecise and potentially inaccurate. There are several ways in which the nervous system may minimize the negative consequences of noise in terms of precision and accuracy. Two key strategies are to combine redundant sensory estimates and to utilize acquired knowledge about the statistical regularities of different sensory signals. In this lecture, I elaborate on how these strategies may be used by the nervous system in order to obtain the best possible estimates from noisy sensory signals, such that we are able of efficiently interact with the environment. Particularly, I will focus on the learning aspects and how our perceptions are tuned to the statistical regularities of an ever changing environment.}, web_url = {http://ukcatalogue.oup.com/product/9780195387247.do}, editor = {Trommershäuser, J. , K.P. Körding, M.S. Landy}, publisher = {Oxford University Press}, address = {New York, NY, USA}, booktitle = {Sensory Cue Integration}, state = {published}, ISBN = {978-0-19-538724-7}, author = {Ernst M{marc}{Research Group Multisensory Perception and Action} and Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}} } @Techreport{ BarnettCowanSZGLd2011, title = {Analysis of perception data and motion perception criteria}, year = {2011}, number = {SUPRA D4.2}, state = {published}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Zaichik L, Groen E, Ledegang W and de Mena M} } @Techreport{ BeykirchBZBL2011, title = {Development of add-on perception model}, year = {2011}, number = {SUPRA D4.3}, state = {published}, author = {Beykirch K{kab}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Zaichik L, Bos J and Ledegang W} } @Poster{ SchindlerKB2011, title = {Decoding egocentric space in human posterior parietal cortex using fMRI}, year = {2011}, month = {11}, volume = {41}, number = {800.21}, abstract = {In our subjective experience, there is a tight link between covert visual attention and ego-centric spatial attention. One key difference is that the latter can extend beyond the visual field, providing us with an accurate mental representation of an object’s location relative to our body position. A neural link between visual and ego-centric spatial attention is suggested by lesions in parietal cortex, that lead not only to deficits in covert visual attention, but frequently also to a disorder of ego-centric spatial awareness, known as hemi-spatial neglect. While parietal involvement in covert visual spatial attention has been much studied, relatively little is known about mental representations of the unseen space around us. In the present study we examined whether also unseen spatial locations beyond the visual field are represented in parietal activity, and how they are related to retinotopic representations. We employed a novel virtual reality (VR) paradigm during functional magnetic resonance imaging (fMRI), whereby observers were prompted to draw their spatial attention to the position of one of eight possible objects located around them in an octagonal room. By changing the observers’ facing direction every few trials, the egocentric location of objects was disentangled from their absolute position and from the objects’ identity. Thus, mental representations of egocentric space surrounding the observer were sampled eight-fold. De-coding results of a multivariate pattern analysis classifier (MVPA), but not univariate results, showed that egocentric spatial directions were specifically represented in parietal cortex. These representations overlapped only partly with visually driven retinotopic activity. Our results thus show that parietal cortex codes not only for retinotopic and visually accessible space, but also for egocentric locations of the three-dimensional space surrounding us, including unseen space.}, web_url = {http://www.sfn.org/AM2011/}, event_name = {41st Annual Meeting of the Society for Neuroscience (Neuroscience 2011)}, event_place = {Washington, DC, USA}, state = {published}, author = {Schindler A{aschindler}{Department Physiology of Cognitive Processes}, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action} and Bartels A{abartels}{Department Physiology of Cognitive Processes}} } @Poster{ PapeWSBM2011, title = {Grid cell remapping in humans}, year = {2011}, month = {11}, volume = {41}, number = {288.05}, abstract = {Grid cells in entorhinal cortex of freely moving rodents were proposed to provide a universal metric of space. They tile the environment into a six-fold symmetric pattern with a particular orientation relative to the environment. The six-fold rotational symmetry of grid patterns can be used to predict a macroscopic signal to functional magnetic resonance imaging (fMRI) in humans [Doeller et al, 2010, Nature]. During hippocampal remapping, grid pattern orientations in rats also change. The purpose of the present study is to examine whether orientation changes (i.e., remapping) can also be found in humans. Participants learned object locations within a virtual room (see Figure 1 left side) and retrieved locations from different start locations during two scanning sessions. They then navigated into an adjacent room and repeated the procedure. We extracted grid orientations from odd trials, and predicted the BOLD response in even trials as a function of the deviation between running direction and the estimated grid orientation for each session. This prediction was significant for the right entorhinal cortex, replicating earlier findings. In 80% of the cases grid cell orientations significantly differed between sessions both within a room and between rooms (see Figure 1 right side). Switching off the virtual environment between sessions for about one minute was seemingly sufficient for that. For male, but not for female participants, grid cell orientation was clustered around the random view of the room experienced at session start. Data suggests that human grid cell orientations can be rather flexible which might be due to the virtuality of the experience. Grid cell orientation might at least for male participants be related to the initial view of an environment.}, web_url = {http://www.sfn.org/am2011/}, event_name = {41st Annual Meeting of the Society for Neuroscience (Neuroscience 2011)}, event_place = {Washington, DC, USA}, state = {published}, author = {Pape A-A{antopia}{Department Human Perception, Cognition and Action}, Wolbers T, Schultz J{johannes}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Meilinger T{meilinger}{Department Human Perception, Cognition and Action}} } @Poster{ TsiatsisN2011, title = {Auditory Processing under Steady State Visual Driving}, year = {2011}, month = {10}, volume = {12}, pages = {44}, abstract = {Neuronal oscillations are considered crucial for information processing in the brain as they can potentially regulate information flow and dynamically bind different cortical and non-cortical regions. This MEG study investigated whether the effect of a transient sound was modulated by the phase of oscillations in the visual cortex. To induce steady state oscillations in the visual cortex, we presented subjects with continuous visual signals luminance-modulated at 4Hz or 10Hz. The transient sounds were presented locked to four phases of the periodic visual stimulus (i.e. 0, 1 2, , 3 4). We then investigated whether the effect of sound depends on the phase of the visual steady state activity by testing for the interaction between sound and visual phase. Conversely, we will investigate the effect of the sound processing on the visual steady state processing given the state of the visual cortex. The results from the two experiments (4Hz & 10Hz) will be combined and compared. Based on recent neurophysiological evidence, we hypothesize that oscillations at different frequencies play distinct functional roles in multisensory integration.}, web_url = {http://www.neuroschool-tuebingen-nena.de/index.php?id=284}, event_name = {12th Conference of Junior Neuroscientists of Tübingen (NeNA 2011)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Tsiatsis P{takis}{Research Group Cognitive Neuroimaging} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Poster{ VolkovaMLAB2011, title = {Contribution of Prosody in Audio-visual Integration to Emotional Perception of Virtual Characters}, journal = {i-Perception}, year = {2011}, month = {10}, volume = {2}, number = {8}, pages = {774}, abstract = {Recent technology provides us with realistic looking virtual characters. Motion capture and elaborate mathematical models supply data for natural looking, controllable facial and bodily animations. With the help of computational linguistics and artificial intelligence, we can automatically assign emotional categories to appropriate stretches of text for a simulation of those social scenarios where verbal communication is important. All this makes virtual characters a valuable tool for creation of versatile stimuli for research on the integration of emotion information from different modalities. We conducted an audio-visual experiment to investigate the differential contributions of emotional speech and facial expressions on emotion identification. We used recorded and synthesized speech as well as dynamic virtual faces, all enhanced for seven emotional categories. The participants were asked to recognize the prevalent emotion of paired faces and audio. Results showed that when the voice was recorded, the vocalized emotion influenced participants’ emotion identification more than the facial expression. However, when the voice was synthesized, facial expression influenced participants’ emotion identification more than vocalized emotion. Additionally, individuals did worse on a identifying either the facial expression or vocalized emotion when the voice was synthesized. Our experimental method can help to determine how to improve synthesized emotional speech.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs3/index.php/imrf/2011/paper/view/263}, web_url2 = {http://i-perception.perceptionweb.com/journal/I/volume/2/article/ic774}, event_name = {12th International Multisensory Research Forum (IMRF 2011)}, event_place = {Fukuoka, Japan}, state = {published}, author = {Volkova E{evolk}{Department Human Perception, Cognition and Action}, Mohler B{mohler}{Department Human Perception, Cognition and Action}, Linkenauger S{sally}{Department Human Perception, Cognition and Action}, Alexandrova I{ivelina}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ SchindlerKB2011_2, title = {Decoding Egocentric Space in human Posterior Parietal Cortex using fMRI}, year = {2011}, month = {10}, volume = {12}, pages = {40}, abstract = {In our subjective experience, there is a tight link between covert visual attention and egocentric spatial attention. One key difference is that the latter can extend beyond the visual field, providing us with an acurate mental representation of an object’s location relative to our body position. A neural link between visual and ego-centric spatial attention is suggested by lesions in parietal cortex, that lead not only to deficits in covert visual attention, but frequently also to a disorder of ego-centric spatial awareness, known as hemi-spatial neglect. While parietal involvement in covert visual spatial attention has been much studied, relatively little is known about mental representations of the unseen space around. In the present study we examined whether also unseen spatial locations beyond the visual field are represented in parietal activity, and how they are related to retinotopic representations. We employed a novel virtual reality (VR) paradigm during functional magnetic resonance imaging (fMRI), whereby observers were prompted to draw their spatial attention to the position of one of eight possible objects located around them in an octagonal room. By changing the observers’ facing direction every few trials, the ego-centric location of objects was disentangled from their absolute position and from the objectsâ identity. Thus, mental representations of egocentric space surrounding the observer were sampled eight-fold. Decoding results of a multivariate pattern analysis classifier (MVPA), but not univariate results, showed that egocentric spatial directions were specifically represented in parietal cortex. These representations overlapped only partly with visually driven retinotopic activity. Our results thus show that parietal cortex codes not only for retinotopic and visually accessible space, but also for ego-centric locations of the three-dimensional space surrounding us, including unseen space.}, web_url = {http://www.neuroschool-tuebingen-nena.de/index.php?id=284}, event_name = {12th Conference of Junior Neuroscientists of Tübingen (NeNA 2011)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Schindler A{aschindler}{Department Physiology of Cognitive Processes}, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action} and Bartels A{abartels}{Department Physiology of Cognitive Processes}} } @Poster{ LeeBBC2011, title = {Fast Fitting on a Saccadic Eye Movement Model for Decision Making}, year = {2011}, month = {10}, volume = {12}, pages = {33}, abstract = {How does our visual system decide where to look? The Linear Approach to Threshold with Ergodic Rate (LATER: Carpenter, 1995) is a simple decision-making model for saccadic eye movements. Currently, experimental data suggest that saccadic eye-movements can be discriminated according to whether they are performed for directed fixations or for item recognition (Montagnini & Chelazzi, 2005; Bieg et al., submitted). Unfortunately, sufficient goodness-of-fit can only be acquired with large datasets, for each individual participant. Here, we investigate whether adapting LATER with modern computational methods can allow for saccades to be classified for their functionality, with minimal data and in real-time. In doing so, we strive towards the eventual goal of using the LATER model for predicting observer intentions in real-world applications.}, web_url = {http://www.neuroschool-tuebingen-nena.de/index.php?id=360}, event_name = {12th Conference of Junior Neuroscientists of Tübingen (NeNA 2011)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Lee JJ{jlee}{Department Human Perception, Cognition and Action}, Bieg H-J{bieg}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Poster{ PapeWSBM2011_2, title = {Grid cell remapping in humans}, year = {2011}, month = {10}, volume = {12}, pages = {38}, abstract = {Grid cells in entorhinal cortex of freely moving rodents were proposed to provide a universal metric of space. They tile the environment into a six-fold symmetric pattern with a particular orientation relative to the environment. The six-fold rotational symmetry of grid patterns can be used to predict a macroscopic signal to functional magnetic resonance imaging (fMRI) in humans [Doeller et al, 2010, Nature]. During hippocampal remapping, grid pattern orientations in rats also change. The purpose of the present study is to examine whether orientation changes (i.e. remapping) can also be found in humans. Participants learned object locations within a virtual room and retrieved locations from different start locations during two scanning sessions. They then navigated into an adjacent room and repeated the procedure. We extracted grid orientations from odd trials, and predicted the BOLD response in even trials as a function of the deviation between running direction and the estimated grid orientation for each session. This prediction was significant for the right entorhinal cortex, replicating earlier findings. In 80% of the cases grid cell orientations significantly differed between sessions both within a room and between rooms. Switching off the virtual environment between sessions for about one minute was seemingly sufficient for that. For male, but not for female participants, grid cell orientation was clustered around the random view of the room experienced at session start. Data suggests that human grid cell orientations can be rather flexible which might be due to the virtuality of the experience. Grid cell orientation might at least for male participants be related to the initial view of an environment.}, web_url = {http://www.neuroschool-tuebingen-nena.de/index.php?id=284}, event_name = {12th Conference of Junior Neuroscientists of Tübingen (NeNA 2011)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Pape A-A{antopia}{Department Human Perception, Cognition and Action}, Wolbers T, Schultz J{johannes}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Meilinger T{meilinger}{Department Human Perception, Cognition and Action}} } @Poster{ SoykaBRB2011, title = {Integration of Translational and Rotational Vestibular Cues for Direction Detection during Eccentric Rotations}, year = {2011}, month = {10}, volume = {12}, pages = {42}, abstract = {During eccentric yaw rotations around an Earth-vertical axis the semi-circular canals are stimulated (rotational acceleration) as well as the otoliths (tangential acceleration). Most likely the brain uses both sensory signals, the canal and the otolith signal, when faced with a rotation direction detection task. Keeping the rotational acceleration profile unchanged and increasing the radius of the eccentric rotation the tangential acceleration increases. Therefore, we hypothesized that thresholds would decrease with increasing radius of rotation. The threshold was defined as the peak acceleration needed to detect the correct direction of motion in 75% of the trials. Ten participants were tested in seven conditions (150 trials each): a head-centered rotation, a translation and five eccentric rotations with varying radii (R=0.1, 0.2, 0.3, 0.5, 0.8 m). The motion had 1s duration and consisted of a single cycle sinusoidal acceleration. Participants were blindfolded, heard white noise and their head was kept in place with a neck brace. The results show a significant decrease of thresholds with increasing radius. It can be seen that the detection process for eccentric rotations is not exclusively based on either the canal or the otolith signal, but that both signals are integrated. A model able to predict the thresholds of the eccentric rotations is proposed, which is solely based on the thresholds for the head-centered rotation and the translational motion. For small radii the detection processes is mainly based on the canal signal whereas for large radii it is dominated by the otolith signal. For intermediate radii the reduction in threshold due to the sensory combination is largest compared to using only one of the two sensors. One additional participant suffered from occasional vertigo after an ear infection indicating vestibular problems. She showed unusually high thresholds for translational motions, but normal thresholds for head-centered rotations. Interestingly, her thresholds for eccentric rotations were higher than her threshold for the head-centered rotations suggesting that she did not only use the rotational signal, but instead had a problem integrating the two sensory signals. These findings indicate that signals from the otolith and the semi-circular canals are not used independently, but are integrated in order to solve a direction detection task.}, web_url = {http://www.neuroschool-tuebingen-nena.de/index.php?id=284}, event_name = {12th Conference of Junior Neuroscientists of Tübingen (NeNA 2011)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ SoykadBGB2011, title = {Integration of visual and vestibular information used to discriminate rotational self-motion}, journal = {i-Perception}, year = {2011}, month = {10}, volume = {2}, number = {8}, pages = {855}, abstract = {Do humans integrate visual and vestibular information in a statistically optimal fashion when discriminating rotational self-motion stimuli? Recent studies are inconclusive as to whether such integration occurs when discriminating heading direction. In the present study eight participants were consecutively rotated twice (2s sinusoidal acceleration) on a chair about an earth-vertical axis in vestibular-only, visual-only and visual-vestibular trials. The visual stimulus was a video of a moving stripe pattern, synchronized with the inertial motion. Peak acceleration of the reference stimulus was varied and participants reported which rotation was perceived as faster. Just-noticeable differences (JND) were estimated by fitting psychometric functions. The visual-vestibular JND measurements are too high compared to the predictions based on the unimodal JND estimates and there is no JND reduction between visual-vestibular and visual-alone estimates. These findings may be explained by visual capture. Alternatively, the visual precision may not be equal between visual-vestibular and visual-alone conditions, since it has been shown that visual motion sensitivity is reduced during inertial self-motion. Therefore, measuring visual-alone JNDs with an underlying uncorrelated inertial motion might yield higher visual-alone JNDs compared to the stationary measurement. Theoretical calculations show that higher visual-alone JNDs would result in predictions consistent with the JND measurements for the visual-vestibular condition.}, web_url = {http://i-perception.perceptionweb.com/journal/I/volume/2/article/ic855}, web_url2 = {http://i-perception.perceptionweb.com/journal/I/volume/2/article/ic855}, event_name = {12th International Multisensory Research Forum (IMRF 2011)}, event_place = {Fukuoka, Japan}, state = {published}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, de Winkel K{ksander}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Groen E{frankg} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ GianiEBKPN2011, title = {Steady-state responses in MEG demonstrate information integration within but not across the auditory and visual senses}, year = {2011}, month = {10}, volume = {12}, pages = {27}, abstract = {To form a unified percept of our environment, the human brain integrates information within and across the senses. This MEG study investigated interactions within and between sensory modalities using a frequency analysis of steady-Ââstate responses (SSR) to periodic auditory and/or visual inputs. The 3x3 factorial design, manipulated (1) modality (auditory only, visual only and audiovisual) and (2) temporal dynamics (static, dynamic1 and dynamic2). In the static conditions, subjects were presented with (1) visual gratings, luminance modulated at 6Hz and/or (2) pure tones, frequency modulated at 40 Hz. To manipulate perceptual synchrony, we imposed additional slow modulations on the auditory and visual stimuli either at same (0.2 Hz = synchronous) or different frequencies (0.2 Hz vs. 0.7 Hz = asynchronous). This also enabled us to investigate the integration of two dynamic features within one sensory modality (e.g. a pure tone frequency modulated at 40Hz & amplitude modulated at 0.2Hz) in the dynamic conditions. We reliably identified crossmodulation frequencies when these two stimulus features were modulated at different frequencies. In contrast, no crossmodulation frequencies were identified when information needed to be combined from auditory and visual modalities. The absence of audiovisual crossmodulation frequencies suggests that the previously reported audiovisual interactions in primary sensory areas may mediate low level spatiotemporal coincidence detection that is prominent for stimulus transients but less relevant for sustained SSR responses. In conclusion, our results indicate that information in SSRs is integrated over multiple time scales within but not across sensory modalities at the primary cortical level.}, web_url = {http://www.neuroschool-tuebingen-nena.de/index.php?id=284}, event_name = {12th Conference of Junior Neuroscientists of Tübingen (NeNA 2011)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Giani A{giani}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging}, Erick O, Belardinelli P, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}, Preissl H and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Poster{ RoheN2012, title = {The ventriloquist effect depends on audiovisual spatial discrepancy and visual reliability}, year = {2011}, month = {10}, volume = {12}, pages = {39}, abstract = {Humans integrate auditory and visual spatial cues to locate objects. Generally, location judgments are dominated by vision because observers localize an auditory cue close to a visual cue even if they have been instructed to ignore the latter (ventriloquist effect). A recent model of multisensory integration proposes that the ventriloquist effect is governed by two principles: First, spatially discrepant cues are only integrated if the observer infers that both cues stem from one object (principle of causal inference). Second, if the inference results in an assumption that both cues originate from one object the cues are integrated by weighting them according to their relative reliability (principle of Bayes-optimal cue weighting). Thus, the bimodal estimate of the object`s location has a higher reliability than each of the unisensory estimates per se. In order to test this model, 26 subjects were presented with spatial auditory (HRTF-convolved white noise) and visual cues (cloud of dots). The 5x5x5 factorial design manipulated (1) the auditory cue location, (2) the visual cue location and (3) the reliability of the visual cue via the width of the cloud of dots. Subjects were instructed to locate the auditory cue while ignoring the visual cue and to judge the spatial unity of both cues. In line with the principle of causal inference results showed that the ventriloquist effect was weaker and unity judgments were reduced for larger audiovisual discrepancies. In case of small spatial discrepancies the ventriloquist effect was weaker at low levels of visual reliability implying a Bayes-optimal strategy of cue weighting only if a common cause of both cues was assumed. A probabilistic model incorporating the principles of causal inference and Bayes-optimal cue weighting accurately fitted the behavioral data. Overall, the pattern of results suggested that both principles describe important processes governing multisensory integration.}, web_url = {http://www.neuroschool-tuebingen-nena.de/index.php?id=284}, event_name = {12th Conference of Junior Neuroscientists of Tübingen (NeNA 2011)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Rohe T{trohe}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Poster{ GaissertWvB2011, title = {Cross-modal transfer in visual and haptic object categorization}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {134}, abstract = {When humans have to categorize objects they often rely on shape as a deterministic feature. However, shape is not exclusive to the visual modality: the haptic system is also an expert in identifying shapes. This raises the question whether humans store separate modality-dependent shape representations or if one multimodal representation is formed. To better understand how humans categorize objects based on shape we created a set of computer-generated amoeba-like objects varing in defined shape steps. These objects were then printed using a 3D printer to generate tangible stimuli. In a discrimination task and a categorization task, participants either visually or haptically explored the objects. We found that both modalities lead to highly similar categorization behavior indicating that the processes underlying categorization are highly similar in both modalities. Next, participants were trained on special shape categories by using the visual modality alone or by using the haptic modality alone. As expected, visual training increased visual performance and haptic training increased haptic performance. Moreover, we found that visual training on shape categories greatly improved haptic performance and vice versa. Our results point to a shared representation underlying both modalities, which accounts for the surprisingly strong transfer of training across the senses.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110108}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action}, Waterkamp S{swaterka}{Department Human Perception, Cognition and Action}, van Dam L{vandam} and B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Poster{ ElzeT2011, title = {Dangerous liquids: Temporal properties of modern LCD monitors and implications for vision science experiments}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {175}, abstract = {In most areas of vision science, liquid crystal displays (LCDs) have widely replaced the long dominating cathode ray tube (CRT) technology. In recent years, however, LCD panels have been repeatedly analyzed and their use been criticized with reference to vision science applications. We measured and analyzed the photometric output of eleven contemporary LCD monitors. Our results show that the specifications given by the manufacturers are partially misleading and mostly insufficient for appropriate display selection for many vision science related tasks. In recent years, novel display technologies have been introduced to improve fast luminance transitions or to optimize the appearance of moving objects. While we found that the luminance transition times of modern LCD monitors are considerably faster than those of earlier LCD generations, these novel technologies may be accompanied by side effects relevant to vision research. Furthermore, we demonstrate a number of intriguing technical deficiencies which may severely impair visual experiments. Several undesired und uncontrolled components of the photometric output as well as unreliable onsets and offsets of visual stimuli require ample measurements prior to applications in all areas of vision science where either precise timing or the knowledge of the exact shape of the photometric output signal matters.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110200}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Elze T and Tanner T{tanner}{Department Human Perception, Cognition and Action}} } @Poster{ SchultzB2011, title = {How does the brain identify living things based on their motion?}, journal = {Journal of Vision}, year = {2011}, month = {9}, volume = {11}, number = {11}, pages = {682}, abstract = {Identifying living moving things in the environment is a priority for animals, as these could be prey, enemies or mates. When the shape of the moving object is hard to see (fog, twilight, great distance, small animal), motion becomes an important cue to detect it. The neural correlates of the detection of an isolated living entity on the basis of its motion are largely unknown. To study this phenomenon, we developed a single-dot stimulus, thus eliminating all possible sources of information about form, spatial arrangement, shape or structure of the object. The dot moved such that it appeared self-propelled, or moved by an external force, or something intermediary according to a small set of parameters. Self-propelled stimuli were perceived as more animate (= more likely to be alive) than the externally-moved stimuli, with a gradual transition occurring in the intermediary morphs following a classic psychometric function (cumulative gaussian). In an fMRI experiment, 20 subjects had to categorize these stimuli into alive and non-alive. A region of the left medial posterior parietal cortex (mPPC) showed BOLD signal correlating with the probability of animacy judgments about the moving dot. While activation in parts of the early visual cortex showed the same response, the mPPC was the only region in which changes in percept had a stronger effect on activation than physical changes in the stimuli. In addition, only the mPPC showed BOLD signal increases when a stimulus was judged to be animate, irrespective of its physical characteristics. This study shows that parts of the early visual cortex but particularly the medial posterior parietal cortex (mPPC) are involved in judging the animacy of an isolated translating visual stimulus, without information about its form.}, web_url = {http://www.journalofvision.org/content/11/11/682.abstract}, event_name = {11th Annual Meeting of the Vision Sciences Society (VSS 2011)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/11.11.682}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ ThorntonHB2011, title = {iMOT: interactive Multiple Object Tracking}, journal = {Journal of Vision}, year = {2011}, month = {9}, volume = {11}, number = {11}, pages = {293}, abstract = {We introduce a novel, iPad-based experimental paradigm to study interactive multiple object tracking (MOT). In standard MOT, participants passively track a set of independently moving objects. We devised a new task in which participants interact with objects, rather than simply track them. We combined a typical MOT display with the path-guidance, touch-screen interface popularised in smart phone games such as Flight Controller and Harbor Master. We ran the experiment using a custom iPad application. A variable number of identical spheres (1.16° visual angle) moved slowly (0.89°/s) on independent linear trajectories within the full iPad display area (22.6° × 17°). Random direction changes occurred at intervals between 4 and 7 s. The participant's goal was to avoid object collisions by manually altering the sphere trajectories. This was achieved by touching the sphere and drawing a short linear or curved path away from it. This action created a visible path, which the sphere followed before resuming default random motion. In this initial study, we constrained path length, in order to prevent participants from creating complex “holding patterns”. A trial ended when the participant successfully avoided collisions for 30 s or when a collision occurred. A sphere was added to the display after a successful trial and removed after a collision, subject to a 6-sphere minimum. Twenty-four participants (ages 18 to 33, mean 23.58, sd 3.45); twelve from Korea University, twelve from Swansea University) completed 30 trials. There were no significant effects of culture, sex or previous gaming experience. The mean number of spheres participants could control was 8.39 (s.e.m. 0.14). This is consistent with estimates of passive tracking capacity at slow speeds. We hypothesize that executive control of scant attentional resources is critical for the current task. In support of this hypothesis, interactive tracking capacity actually increased with age (p = .016).}, web_url = {http://www.journalofvision.org/content/11/11/293.abstract}, event_name = {11th Annual Meeting of the Vision Sciences Society (VSS 2011)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/11.11.293}, author = {Thornton IM{ian}{Department Human Perception, Cognition and Action}, Horowitz TS and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ VolkovaLABM2011, title = {Integration of Visual and Auditory Stimuli in the Perception of Emotional Expression in Virtual Characters}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {138}, abstract = {Virtual characters are a potentially valuable tool for creating stimuli for research investigating the perception of emotion. We conducted an audio-visual experiment to investigate the effectiveness of our stimuli to convey the intended emotion. We used dynamic virtual faces in addition to pre-recorded (Burkhardt et al, 2005, Interspeech'2005, 1517–1520) and synthesized speech to create audio-visual stimuli which conveyed all possible combinations of stimuli. Each voice and face stimuli aimed to express one of seven different emotional categories. The participants made judgments of the prevalent emotion. For the pre-recorded voice, the vocalized emotion influenced participants’ emotion judgment more than the facial expression. However, for the synthesized voice, facial expression influenced participants’ emotion judgment more than vocalized emotion. While participants rather accurately labeled (>76%) the stimuli when face and voice emotion were the same, they performed worse overall on correctly identifying the stimuli when the voice was synthesized. We further analyzed the difference between the emotional categories in each stimulus and found that valence distance in the emotion of the face and voice significantly impacted recognition of the emotion judgment for both natural and synthesized voices. This experimental design provides a method to improve virtual character emotional expression.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110451}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Volkova E{evolk}{Department Human Perception, Cognition and Action}, Linkenauger S{sally}{Department Human Perception, Cognition and Action}, Alexandrova I{ivelina}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler B{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ DobsKBSC2011, title = {Investigating idiosyncratic facial dynamics with motion retargeting}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {115}, abstract = {3D facial animation systems allow the creation of well-controlled stimuli to study face processing. Despite this high level of control, such stimuli often lack naturalness due to artificial facial dynamics (eg linear morphing). The present study investigates the extent to which human visual perception can be fooled by artificial facial motion. We used a system that decomposes facial motion capture data into time courses of basic action shapes (Curio et al, 2006 APGV 1 77–84). Motion capture data from four short facial expressions were input to the system. The resulting time courses and five approximations were retargeted onto a 3D avatar head using basic action shapes created manually in Poser. Sensitivity to the subtle modifications was measured in a matching task using video sequences of the actor performing the corresponding expressions as target. Participants were able to identify the unmodified retargeted facial motion above chance level under all conditions. Furthermore, matching performance for the different approximations varied with expression. Our findings highlight the sensitivity of human perception for subtle facial dynamics. Moreover, the action shape-based system will allow us to further investigate the perception of idiosyncratic facial motion using well-controlled facial animation stimuli.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110293}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Dobs K{kdobs}{Department Human Perception, Cognition and Action}, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}, Schultz J{johannes}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Poster{ ProctorCBT2011, title = {iPad sway: Using mobile devices to indirectly measure performance}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {206}, abstract = {Body sway—the subtle, low frequency movement of the human body measured during quiet-standing—has long been used as a tool to help diagnose a range of medical conditions. It can be measured in a number of ways, including force platforms, sway magnetometry and marker or marker-less motion capture. In the current work—by analogy—we examined whether “iPad sway” could be used as an indirect measure of performance in a simple interactive task. We asked participants to stand and play a simple iPad game that involved tracking and controlling multiple objects using the touch screen. In addition to measuring variations in task performance as a function of set size and object speed, we also used the iPad’s built-in accelerometer to record changes in applied force along three axes. Analysis of this force data revealed both task relevant and task irrelevant components. The former relating directly to task demands—particularly touching the screen—and the latter reflecting idiosyncratic posture and movement patterns that can be used to uniquely identify individual users.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110578}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Proctor KJ, Chen M, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Thrornton IM{ian}{Department Human Perception, Cognition and Action}} } @Poster{ deWinkelSBGB2011, title = {Multisensory integration in the perception of self-motion about an Earth-vertical yaw axis}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {183}, abstract = {Numerous studies report that humans integrate multisensory information in a statistically optimal fashion. However, with respect to self-motion perception, results are inconclusive. Here we test the hypothesis that visual and inertial cues in simulator environments are optimally integrated and that this integration develops over time. Eight participants performed a 2AFC discrimination experiment in visual-only, inertial-only and visual-inertial conditions. Conditions were repeated three times. Inertial motion stimuli were one-period 0.5 Hz sinusoidal acceleration profiles. Visual stimuli were videos of a vertical stripe pattern synchronized with inertial motion. Stimuli were presented in pairs with different peak velocity amplitudes. Participants judged which rotation of a pair had the highest velocity. Precision estimates were derived from psychometric functions. Optimal integration predicts improved precision in the combined condition. However, precision did not differ between the visual and combined conditions. This suggests that participants based their responses predominantly on visual motion. Alternatively, the results could be consistent with optimal integration if the assumption that visual precision remains unchanged during inertial motion was violated. We suggest that a change in visual sensitivity should be considered when investigating optimal integration of visual and inertial cues.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110521}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {de Winkel K{ksander}{Department Human Perception, Cognition and Action}, Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Groen E and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ ChuangS2011, title = {Object speed estimation during walking does not add up}, year = {2011}, month = {9}, web_url = {http://www.bccn-tuebingen.de/news/article/symposium-imultisensory-perception-and-actioni-96.html}, event_name = {Bernstein Cluster D Symposium: Multisensory Perception and Action}, event_place = {Tübingen, Germany}, state = {published}, author = {Chuang LL{chuang}{Department Human Perception, Cognition and Action} and Souman JL{souman}{Department Human Perception, Cognition and Action}} } @Poster{ LeyrerLBKM2011_3, title = {Perception of the size of self and the surrounding visual world in immersive virtual environments}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {209}, abstract = {Newer technology allows for more realistic virtual environments by providing visual image quality that is very similar to that in the real world, this includes adding in virtual self-animated avatars [Slater et al, 2010 PLoS ONE 5(5); Sanchez-Vives et al, 2010 PLoS ONE 5(4)]. To investigate the influence of relative size changes between the visual environment and the visual body, we immersed participants into a full cue virtual environment where they viewed a self-animated avatar from behind and at the same eye-height as the avatar. We systematically manipulated the size of the avatar and the size of the virtual room (which included familiar objects). Both before and after exposure to the virtual room and body, participants performed an action-based measurement and made verbal estimates about the size of self and the world. Additionally we measured their subjective sense of body ownership. The results indicate that the size of the self-representing avatar can change how the user perceives and interacts within the virtual environment. These results have implications for scientists interested in visual space perception and also could potentially be useful for creating positive visual illusions (ie the feeling of being in a more spacious room).}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110436}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Leyrer M{leyrer}{Department Human Perception, Cognition and Action}, Linkenauger SA{sally}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Kloos U and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ diLucaMBE2011, title = {Recalibration of audiovisual simultaneity}, year = {2011}, month = {9}, web_url = {http://www.bccn-tuebingen.de/events/bernstein-symposium-series-2011/symposium-d.html}, event_name = {Bernstein Cluster D Symposium: Multisensory Perception and Action}, event_place = {Tübingen, Germany}, state = {published}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Machulla T{tonja}{Research Group Multisensory Perception and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action} and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Poster{ ChuangBS2011, title = {The center-surround effect in visual speed estimation during walking}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {129}, abstract = {Walking reduces visual speed estimates of optic flow (Souman et al, 2010 Journal of Vision 10(11):14]. Simultaneously, visual background motion can influence the perceived speed of moving objects (Tynan and Sekular, 1975 Vision Research 25 1231–1238; Baker and Graf, 2010 Vision Research 50 193–201). These two effects have been attributed to different subtractive processes, which may help in segregating object motion from self-motion induced optic flow. Here, we investigate how both factors jointly contribute to the perceived visual speed of objects. Participants compared the speed of two central Gabor patches on a ground plane, presented in consecutive intervals, either while standing still or while walking on a treadmill. In half the trials, one of the Gabors was surrounded by a moving random dot pattern, the speed of which matched walking speed. Our results replicated previous findings. A moving surround as well as walking can independently induce a subtractive effect on the perceived speed of the moving center, with the effect size increasing with center speed. However, walking does not affect visual speed estimates of the center when a visual surround is present. These results suggest that the visual input dominates the segregation of object motion from background optic flow.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110345}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Chuang L{chuang}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Souman J{souman}{Department Human Perception, Cognition and Action}} } @Poster{ Streuberd2011, title = {The effect of visual information on motor control in social interaction tasks}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {226}, abstract = {Seeing an object is important for motor control during object interaction. Which sources of visual information are important for motor control in social interaction? In a virtual environment participants hit table tennis balls served by a virtual player. We manipulated the visibility of visual information (ball, racket, body) about the virtual player and the presentation time of the animation (before, during, and after the virtual player’s stroke). We measured the shortest distance between the ball and the participants’ racket. Results: (1) The visibility of each source of information was associated with performance increases; (2) performance did not change when visual information was presented after the virtual player hit the ball; (3) the presentation of the virtual player's racket induced the largest performance improvement shortly before the virtual player hit the ball; (4) performance changes associated with seeing the virtual player’s body were independent of presentation time. In sum participants seem to use multiple sources of visual information about the interaction partner. Moreover visual information about the interaction partner is most useful when seen before the interaction partner's stroke. These results support the hypothesis that the perception of the virtual player affects the online control of own actions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110430}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Streuber S{stst}{Department Human Perception, Cognition and Action} and de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}} } @Poster{ LeyrerLBKM2011_2, title = {The influence of a scaled third-person animated avatar on perception and action in virtual environments}, journal = {Journal of Vision}, year = {2011}, month = {9}, volume = {11}, number = {11}, pages = {69}, abstract = {Newer technology is allowing for virtual environments to become more realistic by providing visual image quality that is very similar to that in the real world. Regardless, egocentric distances estimates in virtual reality have been shown to be underestimated (Thompson et al., 2004). Interestingly, this underestimation decreases after individuals view self-representing avatars in the virtual environment; especially when the avatars are self-animated (Mohler et al., 2010). These finding support perspectives on embodied perception which assert that the body and its action capabilities can act as a “perceptual ruler” that the perceiver uses to scale the world. To test this perspective, we immersed participants into a full-cue, virtual environment where they viewed a self-animated avatar from behind at a distance of 3.5 m away at the same eye-height as the avatar. We manipulated the relationship between the size of the avatar and the size of the virtual room (which included familiar objects) to see if participants would attribute these changes either to the size of the world or to the size of their body. Participants made verbal estimates about the size of self and the world and performed a walking-in-place task. We found that participants verbally attributed the apparent size difference to the virtual world and not to the self which suggests that space perception is grounded in the physical body. Further, we found an influence of condition on the post/pre walking-in-place drift suggesting that the participants felt embodied in the third person animated avatar. Further research needs to be conducted in order to fully understand the relative importance of visual cues about self, such as motion coupling, eye-height and distance of avatar from observer, on perception and action in virtual worlds.}, web_url = {http://www.journalofvision.org/content/11/11/69.abstract}, event_name = {11th Annual Meeting of the Vision Sciences Society (VSS 2011)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/11.11.69}, author = {Leyrer M{leyrer}{Department Human Perception, Cognition and Action}, Linkenauger SA{sally}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Kloos U and Mohler B{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ delaRosaGC2011, title = {The influence of dynamic and static adaptors on the magnitude of high-level aftereffects for dynamic facial expression}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {154}, abstract = {Adapting to an emotional facial expression biases emotional judgments of an ambiguous facial expression away from the adapted facial expression. Previous studies examining emotional facial adaptation effects used static emotional facial expressions as adaptors. Since natural facial expressions are inherently dynamic, dynamic information might enhance the magnitude of the emotional facial expression adaptation effect. We tested this hypothesis by comparing emotional facial expression adaptation effects for static and dynamic facial expression adaptors. Stimuli were generated using a dynamic 3D morphable face model. We found adaptation effects of similar magnitude for dynamic and static adaptors. When rigid head motion was removed (leaving only non-rigid intrinsic facial motion cues), the adaptation effects with dynamic adaptors disappeared. These results obtained with a novel method for the synthesis of facial expression stimuli suggest that at least part of the cognitive representation of facial expressions is dynamic and depends on head motion.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110545}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Giese MA{giese} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Poster{ LeeBAWB2011, title = {The other-race effect is not ubiquitous}, journal = {Journal of Vision}, year = {2011}, month = {9}, volume = {11}, number = {11}, pages = {626}, abstract = {race (the other-race effect or ORE) has been widely cited. Nevertheless, recognizing the identity of a face is a complex task among many others; hence it might be premature to conclude that own-race faces are always easier to process. We investigated whether same-race faces still have a processing advantage over other-race faces when only ethnicity-related information is available to differentiate between faces. We morphed the ethnicity of 20 Caucasians and 20 Asians faces toward their other-race counterpart while keeping their idiosyncratic, identity-related features. Morphing was done at three levels (20%, 50%, and 80% toward the other race). The task for two groups of participants (25 Tübingen and 26 Seoul participants) was to report which face looks more Caucasian (or Asian) after looking at the original face and a morphed face sharing the same idiosyncratic features. Both faces were presented side by side on a computer monitor in one task and sequentially in another task. Importantly, we found no evidence for an ORE in participants’ performance and no performance difference between Tübingen and Seoul participants. Both groups were equally good and equally fast at comparing the ethnicity of two faces regardless of the task, the ethnicity of the faces and the question asked. However, we did find evidence that Seoul and Tübingen participants used different viewing strategies. By investigating their eye-movements in the sequential task, we found that the ethnicity of participants affected fixation durations on specific areas of the face, especially the nose. Also, the type of questions asked and stimulus race altered the pattern of eye movements. These results suggest that although Caucasians and Asians were equally good at dealing with ethnicity information of both races, they might employ different viewing strategies.}, web_url = {http://www.journalofvision.org/content/11/11/626.abstract}, event_name = {11th Annual Meeting of the Vision Sciences Society (VSS 2011)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/11.11.626}, author = {Lee RK{ryokyung}{Department Human Perception, Cognition and Action}, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}, Ammann R, Wallraven C{walli}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ EsinsBS2011, title = {The role of featural and configural information for perceived similarity between faces}, journal = {Journal of Vision}, year = {2011}, month = {9}, volume = {11}, number = {11}, pages = {673}, abstract = {An important aspect of face recognition involves the role of featural and configurational information for face perception (e.g. Tanaka and Farah, 1993; Yovel and Duchaine, 2006; Rotshtein et al, 2007). In our study, we investigated the influence of featural and configural information on perceived similarity between faces. Eight pairs of male faces were chosen from our digital face database (http://faces.kyb.tuebingen.mpg.de). The texture and the face shape for both faces in a pair were equalized to create 2 basis faces that differed only in their inner facial features and their configuration, but not in face shape or texture. A computer algorithm allowed to parametrically morph the features, the configuration, or both between the two basis faces of a pair. In our case the morphing was done in 25% steps. 24 participants rated the similarity between pairs of the created faces using a 7-point Likert scale. The faces to compare came from the same basis face pair and could differ either in features or in configuration by 0%, 25%, 50%, 75% or 100%. The results revealed that for the same amount of morphing, faces differing by their features are perceived as less similar than faces differing by their configurations. These findings replicate previous results obtained with less natural or less controlled conditions. Furthermore, we found that linear increases of the difference between both faces in configural or featural information resulted in a nonlinear increase of perceived dissimilarity. An important aspect for the relevance of our results is how natural the face stimuli look like. We asked 24 participants to rate the naturalness of all stimuli including the original faces and the created faces. Despite numerous manipulations, the vast majority of our created face stimuli were rated as natural as the original faces.}, file_url = {fileadmin/user_upload/files/publications/2011/VSS-2011-Esins.pdf}, web_url = {http://www.journalofvision.org/content/11/11/673.abstract}, event_name = {11th Annual Meeting of the Vision Sciences Society (VSS 2011)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/11.11.673}, author = {Esins J{esins}{Department Human Perception, Cognition and Action}, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action} and Schultz J{johannes}{Department Human Perception, Cognition and Action}} } @Poster{ KaulardFBS2011, title = {Uncovering the principles that allow a distinction of conversational facial expressions}, journal = {Journal of Vision}, year = {2011}, month = {9}, volume = {11}, number = {11}, pages = {605}, abstract = {Facial expressions convey both emotional and conversational signals. Research focuses mostly on EMOTIONAL expressions and consistenly finds that these can be reliably distinguished along at least two dimensions: valence and arousal. CONVERSATIONAL expressions, i.e. those conveying mainly communicative meaning, are thought to be less emotional laden. Interestingly, we found evidence pointing towards the same first two underlying dimensions for CONVERSATIONAL expressions when presented dynamically. The question now arises: "Is the emergence of the valence and arousal dimensions for conversational facial expressions based on the emotional content of these expressions?" To answer this, we used questions addressing the emotional (Fontaine et al, 2007) and the conversational content separately. If the distinction of conversational expressions is based on the small amount of emotional information they might contain, we expect emotional content questions to allow a separation of those expressions. Ten native German participants answered a set of 27 questions for 6 emotional and 6 conversational expressions, both presented statically and dynamically, using a rating scale. A dissimilarity matrix was computed for the expressions. To uncover the meaning of the first two underlying dimensions allowing expression differentiation, multidimensional scaling (MDS) was used. Our results show that static and dynamic emotional expressions can only be distinguished by means of emotional content questions. For these emotional expressions, the valence and arousal dimensions emerged in the MDS. In contrast, conversational expressions can be distinguished using conversational content questions but not using emotional content questions. Unlike emotional expressions, dynamic information improved distinction of conversational expressions substantially. We found evidence for valence and arousal to be the underlying dimensions for conversational expressions. Our results suggest that the distinction of conversational expressions along the first two dimensions is based on conversational rather than emotional content. Moreover, different types of facial expressions benefit to different degrees from dynamic information.}, web_url = {http://www.journalofvision.org/content/11/11/605.abstract}, event_name = {11th Annual Meeting of the Vision Sciences Society (VSS 2011)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/11.11.605}, author = {Kaulard K{kascot}{Department Human Perception, Cognition and Action}, Fernandez Cruz AL{anafer}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Schultz J{johannes}{Department Human Perception, Cognition and Action}} } @Poster{ BulthoffSMT2011, title = {Using avatars to explore height/pitch effects when learning new faces}, journal = {Journal of Vision}, year = {2011}, month = {9}, volume = {11}, number = {11}, pages = {596}, abstract = {In a previous series of desktop experiments we found no evidence that individuals' height influenced their representation of others' faces or their ability to process faces viewed from above or below (VSS 2009). However, in those experiments face orientation and body height were ambiguous as isolated faces were shown on a computer screen to an observer sitting on a chair. To address those concerns and to specifically examine the influence of learned viewpoint, we created a virtual museum containing 20 full-bodied avatars (statues) that were either sitting or standing. Using a head-mounted display, observers walked through this virtual space three times, approached each statue and viewed them from any horizontal (yaw) angle without time restrictions. We equated eye-level - and thus simulated height – for all participants and restricted their vertical movement to ensure that the faces of sitting avatars were always viewed from above and standing avatars from below. After familiarization, recognition was tested using a standard old-new paradigm in which 2D images of the learnt faces were shown from various viewpoints. Results showed a clear influence of learned viewpoint. Faces that had been learned from above (below) were recognized more quickly and accurately in that orientation than from the opposite orientation. Thus, recognition of specific, newly learned faces appears to be view-dependent in terms of pitch angle. Our failure to find a height effect in our previous study suggests that the variety of views of human faces experienced during a lifetime and possibly the preponderance of conversational situations between humans at close range typically counteracts any influence that body size might have on a person's viewing experience of others' faces.}, web_url = {http://www.journalofvision.org/content/11/11/596.abstract}, event_name = {11th Annual Meeting of the Vision Sciences Society (VSS 2011)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/11.11.596}, author = {B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}, Shrimpton S{sezys}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and Thornton IM{ian}{Department Human Perception, Cognition and Action}} } @Poster{ LinkenaugerMB2011, title = {Welcome to Wonderland: The Apparent Size of the Body Influences Perceived Extents in Virtual Environments}, journal = {Journal of Vision}, year = {2011}, month = {9}, volume = {11}, number = {11}, pages = {70}, abstract = {According to the functional approach to the perception of spatial layout, angular optic variables that indicate extents are scaled to the action capabilities of the body (see Proffitt, 2006, POPS, for a review). For example, reachable extents are perceived as a proportion of the maximum extent to which one can reach, and the apparent sizes of graspable objects are perceived as a proportion of the maximum extent that one can grasp (Linkenauger et al., 2009, JEP:HPP; Linkenauger, Ramenzoni, & Proffitt, 2010, Psychol Sci; Witt, Proffitt, & Epstein, 2005, JEP:HPP). Therefore, apparent distances and sizes can be influenced by changing the action capabilities of the body. In order to directly manipulate the perceived action capabilities of the body, participants were immersed into a full cue virtual environment. In real time, participants' hand, arm, and head movements were mapped onto a self-avatar which the participant viewed from the first-person perspective via a head-mounted display. To manipulate perceived action capabilities, the apparent size of the participants' hand was altered by decreasing or increasing the size of the self-avatar's virtual hand (small, normal, and large). Participants estimated the sizes of various objects in the virtual environment. Participants perceived objects to be larger when their virtual hand was smaller and perceived objects to be smaller when their virtual hand was larger. Consistent with the functional approach, the differences in apparent size across the conditions increased as a function of object size, suggesting changes in the scaling metric rather than a constant bias.}, web_url = {http://www.journalofvision.org/content/11/11/70.abstract}, event_name = {11th Annual Meeting of the Vision Sciences Society (VSS 2011)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/11.11.70}, author = {Linkenauger SA{sally}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ KaularddSFBW2011, title = {What are the properties underlying similarity judgments of facial expressions?}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {115}, abstract = {Similarity ratings are used to investigate the cognitive representation of facial expressions. The perceptual and cognitive properties (eg physical aspects, motor expressions, action tendencies) driving the similarity judgments of facial expressions are largely unknown. We examined potentially important properties with 27 questions addressing the emotional and conversational content of expressions (semantic differential). The ratings of these semantic differentials were used as predictors for facial expression similarity ratings. The semantic differential and similarity-rating task were performed on the same set of facial expression videos: 6 types of emotional (eg happy) and 6 types of conversational (eg don’t understand) expressions. Different sets of participants performed the two tasks. Multiple regression was used to predict the similarity data from the semantic differential questions. The best model for emotional expressions consisted of two emotional questions explaining 75% of the variation in similarity ratings. The same model explained significantly less variation for conversational expressions (38%). The best model for those expressions consisted of a single conversational question explaining 44% of the variation. This study shows which properties of facial expressions might affect their perceived similarity. Moreover, our results suggest that different perceptual and cognitive properties might underlie similarity judgments about emotional and conversational expressions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110290}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Kaulard K{kascot}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Schultz J{johannes}{Department Human Perception, Cognition and Action}, Fernandez Cruz AL{anafer}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Poster{ SchultzBP2011, title = {What human brain regions like about moving faces?}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {116}, abstract = {Visual perception of moving faces activates parts of the human superior temporal sulcus (STS) whereas static facial information is mainly processed in areas of ventral temporal and lateral occipital cortex. However, recent findings show that the latter regions also respond more to moving faces than to static faces. Here, we investigated the origin of this activation increase, considering the following causes: (i) facial motion per se, (ii) increased static information due to the higher number of frames constituting the movie stimuli, and/or (iii) increased attention towards moving faces. We presented non-rigidly moving faces to subjects in an fMRI scanner. We manipulated static face information and motion fluidity by presenting ordered and scrambled sequences of frames at the original or reduced temporal resolutions. Subjects performed a detection task unrelated to the face stimuli in order to equate attentional influences. Results confirm the increased response due to facial motion in the face-sensitive temporal regions. Activation generally increased with the number of frames but decreased when frames were scrambled. These results indicate that the activation increase induced by moving faces is due to smooth, natural motion and not only to increased static information or attentional modulation.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110303}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action}, Brockhaus M{mabrockhaus}{Department Human Perception, Cognition and Action} and Pilz K{kpilz}{Department Human Perception, Cognition and Action}} } @Poster{ ReichenbachBBT2011, title = {Role of the PPC in vestibular information processing during goal-directed movements tested with TMS}, year = {2011}, month = {6}, number = {940}, abstract = {fMRI and TMS studies have shown that visual and proprioceptive information for motor control are integrated in the posterior parietal cortex (PPC) (e.g. Culham and Valyear, 2006; Filimon et al., 2009; Reichenbach et al., 2010). When the head is moving in space during a goal-directed movement, vestibular signals have to be integrated into the motor processing as well. The neural correlates of these integration processes during motor control have not been investigated thus far. However, fMRI studies about vestibular stimulation have shown that the PPC is also processing vestibular information (Suzuki et al., 2001; Dieterich et al., 2003; Stephan et al., 2005). Furthermore, Seemungal et al. (2008) demonstrated that the administration of TMS over the PPC disturbs the perception of the position in space when the body is rotated. For the TMS study presented here, we used the behavioral paradigm of Bresciani et al. (2002) where subjects performed a goal-directed reaching task while suddenly being rotated. In order to assess the neural correlates of vestibular information processing for movement control, we probed with TMS the necessity of several sites on the PPC for this motor task.}, file_url = {fileadmin/user_upload/files/publications/2011/HBM-2011-Reichenbach.pdf}, web_url = {http://www.humanbrainmapping.org/i4a/pages/index.cfm?pageID=3419}, event_name = {17th Annual Meeting of the Organization for Human Brain Mapping (HBM 2011)}, event_place = {Québec City, Canada}, state = {published}, author = {Reichenbach A{areichen}{Department Human Perception, Cognition and Action}{Department High-Field Magnetic Resonance}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Thielscher A{thielscher}{Department High-Field Magnetic Resonance}} } @Poster{ GianiOBKPN2011, title = {Using steady state responses in MEG to study information integration within and across the senses}, year = {2011}, month = {6}, number = {1028}, abstract = {How does the brain integrate information within and across sensory modalities to form a unified percept? This question has previously been addressed using transient stimuli, analyzed in the time domain. Alternatively, sensory interactions can be investigated using frequency analyses of steady state responses (SSRs). SSRs are elicited by periodic sensory stimulation (such as frequency modulated tones). In the frequency domain, 'true' signal integration is reflected by non-linear crossmodulation terms (i.e. the sums and differences of the individual SSR frequencies). In addition, two signals may modulate the amplitude of the fundamental and harmonic frequencies of one another. Using visual (V) and auditory (A) SSRs, we investigated whether A and V signals are truly integrated as indexed by crossmodulation terms or simply modulate the expression of each other's dominant frequencies. To manipulate perceptual synchrony, we imposed additional slow modulations on the auditory and visual SSRs either at same or different frequencies. This also enabled us to investigate the integration of two dynamic features within one sensory modality.}, file_url = {fileadmin/user_upload/files/publications/2011/HBM-2011-Giani.pdf}, web_url = {http://www.humanbrainmapping.org/i4a/pages/index.cfm?pageID=3419}, event_name = {17th Annual Meeting of the Organization for Human Brain Mapping (HBM 2011)}, event_place = {Québec City, Canada}, state = {published}, author = {Giani AS{giani}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging}, Ortiz EB, Belardinelli P, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}, Preissl H and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Poster{ DavidSVE2011_2, title = {Individuals with autism are impaired in social animacy perception but not in lower-level animacy or coherent motion perception}, year = {2011}, month = {4}, web_url = {http://www.mrc-cbu.cam.ac.uk/socialbrain2011/}, event_name = {The Social Brain Workshop 2011}, event_place = {Cambridge, UK}, state = {published}, author = {David N, Schultz J{johannes}{Department Human Perception, Cognition and Action}, Vogeley K and Engel A} } @Poster{ DavidSVE2011, title = {Individuals with Autism Show a Selective Deficit for the Understanding of Interacting Animated Objects}, journal = {Journal of Cognitive Neuroscience}, year = {2011}, month = {3}, volume = {23}, number = {Supplement}, pages = {64}, abstract = {A focus on social deficits in autism spectrum disorders (ASD) has, for a long time, obscured the existence of lower-level perceptual abnormalities, although the earliest descriptions of autism included abnormalities in oculomotor behavior and visual attention. More recently, however, abnormalities in perception and attention have increasingly been discussed as influential factors in ASD-specific psychopathology. To this end, the perception of coherent motion in random-dot kinematograms, biological motion in point-light walkers and agency in animated shapes have been investigated in ASD but their relationship remains a matter of debate. It also is unclear whether ASD-related deficits result from difficulties in global motion perception or in processing motion that contains socially relevant signals (e.g. a body and actions). We tested 18 individuals with highfunctioning autism and 16 age-, gender- and IQ-matched control participants, who performed three tasks on a continuum of motion cues and social complexity: (1) low-level translational motion that moved up or down, (2) complex motion of a single dot that moved in an animate or inanimate way, (3) complex motion of two dots that interacted or not. None of these tasks contained objects with human shape and only the first task contained global motion. Participants with autism were selectively impaired in detecting social interaction between two animated shapes (task 3), while low-level motion processing (task 1) and the detection of isolated agents (task 2) were preserved. These findings suggest a distinct social impairment in ASD in understanding interacting agents.}, web_url = {http://cogneurosociety.org/annual-meeting/previous-meetings/CNS2011_Program.pdf/view}, event_name = {18th Annual Meeting of the Cognitive Neuroscience Society (CNS 2011)}, event_place = {San Francisco, CA, USA}, state = {published}, author = {David N, Schultz J{johannes}{Department Human Perception, Cognition and Action}, Vogeley K and Engel A} } @Thesis{ Alexandrova2011, title = {Generating Virtual Humans Using Predefined Bodily and Facial Emotions in Real-Time Immersive Virtual Environments}, year = {2011}, month = {1}, day = {17}, file_url = {fileadmin/user_upload/files/publications/2011/IvelinaAlexandrova-MasterThesis.pdf}, state = {published}, type = {Master}, author = {Alexandrova IV{ivelina}{Department Human Perception, Cognition and Action}} } @Thesis{ Chuang2011_5, title = {Recognizing Objects From Dynamic Visual Experiences}, year = {2011}, web_url = {http://www.logos-verlag.de/cgi-bin/buch/isbn/2842}, state = {published}, type = {PhD}, author = {Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Thesis{ Engel2011, title = {Shape-Centered Representations: From Features to Applications}, year = {2011}, web_url = {http://www.logos-verlag.de/cgi-bin/buch/isbn/2820}, state = {published}, type = {PhD}, author = {Engel D{engel}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2011_4, title = {Bilateral Teleoperation of Multi-Robot Systems: Passivity, Decentralization, and Connectivity Maintenance}, year = {2011}, month = {12}, day = {14}, event_name = {Oberseminar Intelligent Autonomous Systems Group, Technische Universität Darmstadt}, event_place = {Darmstadt, Germany}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2011_3, title = {Bilateral Teleoperation of Groups of Mobile Robots}, year = {2011}, month = {11}, day = {25}, web_url = {http://www.dii.unisi.it/}, event_name = {SIRSLab, Dipartimento di Ingegneria dell'Informazione Università di Siena}, event_place = {Siena, Italy}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2011_3, title = {Bilateral Teleoperation of Groups of Mobile Robots: from Fixed to Time-Varying Topology}, year = {2011}, month = {11}, day = {25}, web_url = {http://www.dii.unisi.it/}, event_name = {SIRSLab, Dipartimento di Ingegneria dell'Informazione Università di Siena}, event_place = {Siena, Italy}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ LeoN2011_2, title = {Monetary conditioning influences audio-visual integration by increasing sound saliency}, year = {2011}, month = {11}, day = {18}, pages = {7}, abstract = {We investigated the effect of prior conditioning an auditory stimulus on audiovisual integration in a series of three psychophysical experiments. The three experiments employed the same acquisition phase (monetary conditioning) but different multisensory paradigms (Exp1: 2AFC visual detection; Exp2: redundant target paradigm; Exp3: redundant target paradigm using near threshold visual and auditory stimuli). In the acquisition phase, subjects were presented with three pure tones (= conditioned stimuli, CSs) that were paired with positive, negative or neutral unconditioned stimuli (USs, monetary: +50 euro cents, -50 cents, 0 cents). In a 2AFC visual selective attention paradigm, detection of near-threshold Gabors was improved by concurrent sounds that had previously been paired with a positive outcome relative to neutral sounds. Taken together, redundant target paradigms results showed that sounds previously paired with positive or negative outcomes increased response speed to both auditory and audiovisual targets similarly. Importantly, prior conditioning did not increase the multisensory response facilitation (i.e. (A+V)/2-AV) or the race model violation. Collectively, our results suggest that prior conditioning primarily increases the saliency of the auditory stimulus per se rather than influencing audiovisual integration directly. In turn, conditioned sounds are rendered more potent for increasing response accuracy or speed in detection of visual targets.}, web_url = {http://www.sinp-web.org/site/}, event_name = {Riunione Autunnale di Società Italiana di Neuropsicologia (SINP 2011)}, event_place = {Bologna, Italy}, state = {published}, author = {Leo F{leo78}{Research Group Cognitive Neuroimaging} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Conference{ BulthoffN2011_2, title = {myCopter: Enabling Technologies for Personal Aerial Transportation Systems}, year = {2011}, month = {11}, day = {4}, web_url = {http://www.airtec.aero/index.php?id=55}, event_name = {3rd International HELI World Conference 2011 "HELICOPTER Technologies and Operations"}, event_place = {Frankfurt a.M., Germany}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}} } @Conference{ Chuang2011_4, title = {Perception of the active observer}, year = {2011}, month = {11}, day = {2}, abstract = {As active observers, we move our eyes, re-orient our bodies and even manipulate our environment to access task-relevant information. The purpose of this talk is demonstrate that our understanding of human behavior can be enriched by considering that the observer is often-times responsible for his own perceptual input. I will do so by first presenting research that: a) addressed how object speeds are estimated during locomotion, b) investigated how we explore objects during learning for subsequent recognition. Following this, I will present research in two application scenarios that exemplifies the role of the active observer — namely, teleoperation of swarm-UAVs and gazetracking on wall-sized displays.}, web_url = {http://ikw.uni-osnabrueck.de/en/node/680}, event_name = {Institute of Cognitive Science, Universität Osnabrück}, event_place = {Osnabrück, Germany}, state = {published}, author = {Chuang L{chuang}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2011_8, title = {Science and Science Fiction: closing the loop between Perception and Technology}, year = {2011}, month = {10}, day = {5}, web_url = {http://brain.korea.ac.kr/eng/}, event_name = {Department of Brain and Cognitive Engineering, Korea University}, event_place = {Seoul, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2011_2, title = {Passivity-based Decentralized Bilateral Teleoperation of Groups of Mobile Robots with Fixed and Time-Varying Topology}, year = {2011}, month = {10}, day = {3}, abstract = {This talk will present some recent theoretical and experimental results in the relatively new topic of Bilateral Teleoperation of Multiple Mobile Robots, with special regard to the Unmanned Aerial Vehicle (UAV) case. In this non-conventional teleoperation field a human operator partially controls the behavior of a semi-autonomous swarm of mobile-robots by means of one or more haptic interfaces, and receives back a force cue which is informative both of the swarm tracking performance and of some relevant properties of the surrounding environment (e.g., presence of obstacles or other threats). This kind of systems are designed in order to enhance the telepresence of the operator and the quality of the human robot interaction, especially when applied to practical scenarios, like search and rescue, surveillance, exploration and mapping. The focus of the talk will be on the design of a stable bilateral interconnection between the user and the group of robots considered either (1) as a deformable object with a given shape (fixed topology) to be achieved with suitable formation control algorithms, or (2) a swarm of agents with time-varying topology which dynamically adapts to the environment while preserving the global connectivity and selects the best leader in a decentralized way.}, web_url = {http://www.ccdc.ucsb.edu/?q=content/passivity-based-decentralized-bilateral-teleoperation-groups-mobile-robots-fixed-and-time-va}, event_name = {Center for Control, Dynamical-Systems, and Computation (CCDC), University of California}, event_place = {Santa Barbara, CA, USA}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ GaissertWvBW2011, title = {Efficient cross-modal transfer of shape information in visual and haptic object categorization}, journal = {i-Perception}, year = {2011}, month = {10}, volume = {2}, number = {8}, pages = {822}, abstract = {Categorization has traditionally been studied in the visual domain with only a few studies focusing on the abilities of the haptic system in object categorization. During the first years of development, however, touch and vision are closely coupled in the exploratory procedures used by the infant to gather information about objects. Here, we investigate how well shape information can be transferred between those two modalities in a categorization task. Our stimuli consisted of amoeba-like objects that were parametrically morphed in well-defined steps. Participants explored the objects in a categorization task either visually or haptically. Interestingly, both modalities led to similar categorization behavior suggesting that similar shape processing might occur in vision and haptics. Next, participants received training on specific categories in one of the two modalities. As would be expected, training increased performance in the trained modality; however, we also found significant transfer of training to the other, untrained modality after only relatively few training trials. Taken together, our results demonstrate that complex shape information can be transferred efficiently across the two modalities, which speaks in favor of multisensory, higher-level representations of shape.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs3/index.php/imrf/2011/paper/view/430}, web_url2 = {http://i-perception.perceptionweb.com/journal/I/volume/2/article/ic822}, event_name = {12th International Multisensory Research Forum (IMRF 2011)}, event_place = {Fukuoka, Japan}, state = {published}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action}, Waterkamp S{swaterka}{Department Human Perception, Cognition and Action}, van Dam L{vandam}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Conference{ Kleiner2011, title = {Fairy tales & horror stories: Common misconceptions and traps about use of computers for psychophysical testing}, year = {2011}, month = {10}, volume = {12}, pages = {10}, abstract = {This talk will describe some very common misconceptions that cognitive neuroscientists frequently express about the use of computers and related equipment for visual or auditory stimulus presentation, response collection and the timing precision and behaviour of computers and common operating systems in general. Some typical examples are assumptions about the suitability of LCD flat panels for timed and controlled visual stimulation, naive use of standard sound cards for timed auditory stimulation, and the use of keyboards and mice for reaction time measurements. The talk will try to point out solutions or remedies for some problems where available. The examples are based on an informal sampling of questions asked and misconceptions often encountered on the Psychtoolbox user forum.}, web_url = {http://www.neuroschool-tuebingen-nena.de/index.php?id=284}, event_name = {12th Conference of Junior Neuroscientists of Tübingen (NeNA 2011)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}} } @Conference{ Chuang2011_3, title = {Moving objects: From object speed estimation to object exploration}, year = {2011}, month = {10}, web_url = {http://www.liv.ac.uk/psychology/}, event_name = {Department of Psychology, University of Liverpool}, event_place = {Liverpool, UK}, state = {published}, author = {Chuang L{chuang}{Department Human Perception, Cognition and Action}} } @Conference{ Chuang2011_2, title = {The active observer: Implications for science and engineering}, year = {2011}, month = {10}, web_url = {http://www.tno.nl/content.cfm?context=thema&content=markt_product&laag1=892&laag2=184&laag3=401&item_id=1581&Taal=1}, event_name = {TNO Human Factors}, event_place = {Soesterberg, Netherlands}, state = {published}, author = {Chuang L{chuang}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2011_9, title = {Plenary II: BioRobotics}, year = {2011}, month = {9}, day = {27}, web_url = {http://www.iros2011.org/plenary-sessions}, event_name = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011)}, event_place = {San Francisco, CA, USA}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2011_7, title = {Perceptual Graphics: closing the loop between Perception, Graphics and Computer Vision}, year = {2011}, month = {9}, day = {22}, abstract = {In our Perceptual Graphics group at the Max Planck Institute for Biological Cybernetics we integrate methods from psychophysics, computer graphics and computer vision in order to understand fundamental perceptual and cognitive processes. The fusion of methods from these research areas has the potential to greatly advance our understanding of perception and cognition. Highly controllable, yet realistic computergenerated stimuli offer novel ways for psychophysical investigations. The results from those experiments can in turn be used to derive perceptual "shortcuts" to more efficient rendering approaches. Computer vision and machine learning algorithms can be used to model human cognition and action while conversely, the results from perceptual experiments can inform computer scientists how the brain solves problems and thus can lead to more efficient solutions of hard problems like recognition and categorization. In this presentation, I will highlight how the latest tools in computer vision, computer graphics, and virtual reality technology can be used to systematically understand the factors that determine how humans behave and solve tasks in realistic scenarios.}, web_url = {http://graphics.csie.ncku.edu.tw/PG2011/}, event_name = {19th Pacific Conference on Computer Graphics and Applications (Pacific Graphics 2011)}, event_place = {Kaoshiung, Taiwan}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ SecchiRF2011, title = {Decentralized and Passivity based Teleoperation of a Group of UAVs with Time-Varying Topology}, year = {2011}, month = {9}, web_url = {http://www.convegnoautomaticaitaliana.org/index.html}, event_name = {Automatica.it 2011}, event_place = {Pisa, Italy}, state = {published}, author = {Secchi C, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ ThorntonCMB2011, title = {Exploring motion-induced illusory displacement using interactive games}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {27-28}, abstract = {Motion-induced illusory displacement occurs when local motion within an object causes its perceived global position to appear shifted. Using two different paradigms, we explored whether active control of the physical position of the object can overcome this illusion. In Experiment 1, we created a simple joystick game in which participants guided a Gabor patch along a randomly curving path. In Experiment 2, participants used the accelerometer-based tilt control of the iPad to guide a Gabor patch through a series of discrete gates, as might be found on a slalom course. In both experiments, participants responded to local motion with overcompensating movements in the opposite direction, leading to systematic errors. These errors scaled with speed but did not vary in magnitude either within or across trials. In conclusion, we found no evidence that participants could adapt or compensate for illusory displacement given active control of the target.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110552}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Thornton IM{ian}{Department Human Perception, Cognition and Action}, Canaird F, Mamassian P{pascal}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ LinkenaugerMB2011_2, title = {Welcome to wonderland: The apparent size of the self-avatar hands and arms influences perceived size and shape in virtual environments}, journal = {Perception}, year = {2011}, month = {9}, volume = {40}, number = {ECVP Abstract Supplement}, pages = {46}, abstract = {Welcome to wonderland: The apparent size of the self-avatar hands and arms influences perceived size and shape in virtual environments S A Linkenauger, B J Mohler, H H Bülthoff According to the functional approach to the perception of spatial layout, angular optic variables that indicate extents are scaled to the body and its action capabilities [cf Proffitt, 2006 Perspectives on Psychological Science 1(2) 110–122]. For example, reachable extents are perceived as a proportion of the maximum extent to which one can reach, and the apparent sizes of graspable objects are perceived as a proportion of the maximum extent that one can grasp (Linkenauger et al, 2009 Journal of Experimental Psychology: Human Perceptiion and Performance; 2010 Psychological Science). Therefore, apparent sizes and distances should be influenced by changing scaling aspects of the body. To test this notion, we immersed participants into a full cue virtual environment. Participants’ head, arm and hand movements were tracked and mapped onto a first-person, self-representing avatar in real time. We manipulated the participants’ visual information about their body by changing aspects of the self-avatar (hand size and arm length). Perceptual verbal and action judgments of the sizes and shapes of virtual objects’ (spheres and cubes) varied as a function of the hand/arm scaling factor. These findings provide support for a body-based approach to perception and highlight the impact of self-avatars’ bodily dimensions for users’ perceptions of space in virtual environments.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v110592}, event_name = {34th European Conference on Visual Perception}, event_place = {Toulouse, France}, state = {published}, author = {Linkenauger S{sally}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Chuang2011, title = {How do we seek out information?}, year = {2011}, month = {8}, day = {29}, abstract = {Many tasks require us to access relevant information from a dynamic visual input. To do so, we move our eyes and bodies as well as manipulate our environments. Unfortunately, experiments on human behavior tend to ignore this fact, often to the detriment of their ecological validity. Our understanding can be better informed by studying how humans actively seek out relevant information in their unrestrained and task-relevant workspaces. I will present several research studies from our lab to demonstrate this point. These studies relate to how humans explore novel objects, unrestrained gaze measurements on wall-sized displays, and the influence of haptic force feedback on the teleoperation of micro unmanned aerial vehicles. Finally, I will introduce our latest research project that targets the implications of a personal air transport system (www.mycopter.eu).}, file_url = {fileadmin/user_upload/files/publications/2011/D-CIS-Lab-2011-Chuang.pdf}, web_url = {http://www.d-cis.nl/news/210-colloquium-how-do-we-seek-out-information-}, event_name = {D-CIS Lab Colloquium}, event_place = {Delft, Netherlands}, state = {published}, author = {Chuang L{chuang}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2011_4, title = {Towards Artificial Systems: What Can We Learn From Human Perception?}, year = {2011}, month = {8}, day = {11}, abstract = {Recent progress in learning algorithms and sensor hardware has led to rapid advances in artificial systems. However, their performance continues to fall short of the efficiency and plasticity of human behavior. In many ways, a deeper understanding of how humans process and act upon physical sensory information can contribute to the development of better artificial systems. In this presentation, Buelthoff will highlight how the latest tools in computer vision, computer graphics, and virtual reality technology can be used to systematically understand the factors that determine how humans behave and solve tasks in realistic scenarios.}, web_url = {http://www.aaai.org/Conferences/AAAI/2011/aaai11speakers.php}, event_name = {Twenty-Fifth AAAI Conference on Artificial Intelligence (AAAI-11)}, event_place = {San Francisco, CA, USA}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2011_5, title = {Wie kommt die Welt in den Kopf?: Von der Grundlagenforschung zur Anwendung}, year = {2011}, month = {7}, day = {30}, web_url = {http://www.leinroden.de/}, event_name = {Lingelbachs Scheune – Optische Phänomene e.V.}, event_place = {Abtsgmünd, Germany}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2011_3, title = {Wahrnehmen, begreifen und handeln: Die Kommunikation des Menschen mit seinen Hifsmitteln}, year = {2011}, month = {7}, day = {6}, event_name = {Tübinger Innovationstage 2011 der Industrie- und Handelskammer Reutlingen}, event_place = {Tübingen, Germany}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Breidt2011_2, title = {3D-Mimikanalyse}, year = {2011}, month = {7}, event_name = {Tübinger Innovationstage 2011 der Industrie- und Handelskammer Reutlingen}, event_place = {Tübingen, Germany}, state = {published}, author = {Breidt M{mbreidt}{Department Human Perception, Cognition and Action}} } @Conference{ ThorntonCMB2011_2, title = {Active control does not eliminate motion-induced illusory displacement}, journal = {i-Perception}, year = {2011}, month = {7}, volume = {2}, number = {4}, pages = {209}, abstract = {When the sine-wave grating of a Gabor patch drifts to the left or right, the perceived position of the entire object is shifted in the direction of local motion. In the current work we explored whether active control of the physical position of the patch overcomes such motion induced illusory displacement. In Experiment 1 we created a simple computer game and asked participants to continuously guide a Gabor patch along a randomly curving path using a joystick. When the grating inside the Gabor patch was stationary, participants could perform this task without error. When the grating drifted to either left or right, we observed systematic errors consistent with previous reports of motion-induced illusory displacement. In Experiment 2 we created an iPad application where the built-in accelerometer tilt control was used to steer the patch through as series of “gates”. Again, we observed systematic guidance errors that depended on the direction and speed of local motion. In conclusion, we found no evidence that participants could adapt or compensate for illusory displacement given active control of the target.}, file_url = {fileadmin/user_upload/files/publications/2011/APCV-2011-Thornton.pdf}, web_url = {http://i-perception.perceptionweb.com/journal/I/article/ic209}, event_name = {7th Asia-Pacific Conference on Vision (APCV 2011)}, event_place = {Hong Kong}, state = {published}, author = {Thornton IM{ian}{Department Human Perception, Cognition and Action}, Caniard F{franck}{Department Human Perception, Cognition and Action}, Mamassian P{pascal}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ BulthoffAWB2011, title = {Investigating the other-race effect in different face recognition tasks}, journal = {i-Perception}, year = {2011}, month = {7}, volume = {2}, number = {4}, pages = {355}, abstract = {Faces convey various types of information like identity, ethnicity, sex or emotion. We investigated whether the well-known other-race effect (ORE) is observable when facial information other than identity varies between test faces. First, in a race comparison task, German and Korean participants compared the ethnicity of two faces sharing similar identity information but differing in ethnicity. Participants reported which face looked more Asian or Caucasian. Their behavioral results showed that Koreans and Germans were equally good at discriminating ethnicity information in Asian and Caucasian faces. The nationality of participants, however, affected their eye-movement strategy when the test faces were shown sequentially, thus, when memory was involved. In the second study, we focused on ORE in terms of recognition of facial expressions. Korean participants viewed Asian and Caucasian faces showing different facial expressions for 100ms to 800ms and reported the emotion of the faces. Surprisingly, under all three presentation times, Koreans were significantly better with Caucasian faces. These two studies suggest that ORE does not appear in all recognition tasks involving other-race faces. Here, when identity information is not involved in the task, we are not better at discriminating ethnicity and facial expressions in same race compared to other race faces.}, web_url = {http://i-perception.perceptionweb.com/journal/I/volume/2/article/ic355}, event_name = {7th Asia-Pacific Conference on Vision (APCV 2011)}, event_place = {Hong Kong}, state = {published}, author = {Lee RK{ryokyung}{Department Human Perception, Cognition and Action}, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}, Armann R{armann}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2011_2, title = {Science and Science Fiction: closing the loop between Cognition and Application}, year = {2011}, month = {6}, day = {20}, event_name = {Università degli Studi di Genova}, event_place = {Genova, Italy}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Volkova2011, title = {PETaLS: Perception of Emotions in Text - a Linguistic Simulation}, year = {2011}, month = {6}, abstract = {The emotional aspect is an integral part of human-human interaction. There are few spheres where emotional communication is unnecessary or not desirable. Feelings, opinions and attitudes are often expressed in text, which makes senti- ment analysis (SA) very needed and valuable. Most existing sentiment analysis systems are implemented for and used in specific predefined areas. The applica- tion field could be anything from extracting appraisal expressions (Whitelaw et al., 2005) to opinion mining of customer feedback (Lee et al., 2008). PETaLS, the SA system we have recently developed, has its intended applica- tion in emotion enhancement of human-computer interaction, especially in virtual or augmented reality. The project is based on supervised machine learning and is meant to build a bridge between unprocessed input text and visual and auditory information, coming from the virtual character, like generated speech, facial ex- pressions and body language. This would enable a virtual character to simulate emotional perception and production of text in story telling scenarios. Thus the first step towards building the PETaLS system was to collect a reli- able corpus of texts that are annotated for emotional states, which could later be used for training and testing. We conducted two annotation experiments: a pilot study in which a few selected texts were analyzed by several participants each and a large scale experiment where more than 70 texts were annotated by two participants each. The main goal of the first experiment, which was presented at the previous TaCoS conference (Volkova et al., 2010), is to research the nature of the sentiment analysis performed by humans and to examine whether they can reliably perform the task. The second experiment aimed at collecting of a corpus of reliable data of adequate size for ML training and testing. For both experiments, we chose Brother Grimms fairy tales as the main anno- tation material. One of the challenges was to analyze inter-annotator agreement, which could not be accurately measured with the help of classical methods (Art- stein, 2008) due to the complexity of the annotation task. However, our more flexible approach to annotations comparison showed consistent similarity between annotators as thus proved the acceptable quality of the collected corpora: on av- erage 53% in the first experiment and 66% for the second. We used a chain of NLP tools (Schmid, 1994, 1999; Klein & Manning, 2002; Kunze, 2004; Hinrichs et al., 2009) to analyze the initial texts and to retrieve a large number of linguistic features which then were employed by the TiMBL (Daelemans et al., 2004) for training and testing. A few of the used features, to the best of our knowledge, had never been mentioned in the relevant literature, e.g., finding nouns that occur several times in a story, thus referring to characters and objects that are important for the plot and have a higher chance to trigger emotional states. Classification was performed on short phrases where each classification item was represented by feature values describing the item itself and its closest neigh- bors to the left and to the right. We developed a hierarchy of emotional classes, which assisted deeper understanding of automatic classification problems and in- dicated where the improvements should be made. The accuracy of our classifiers ranges from 47% to 81%, depending on the classification task. Each time the major baseline is outperformed and our results are comparable with those of other researches. The most successful approach is when we only distinguish between three emotional categories: positive, negative and neutral, the accuracy for this classification task is 68%, which is 1.7 higher than the corresponding baseline of 40%. Since each story can be told in various acceptable ways, we conducted a human test were we applied PETaLS-generated emotion annotations of several texts to the Virtual Story Teller Framework (Alexandrova et al., 2010). They were evaluated by ten participants along with virtual story telling session driven by human annotations. At the current stage of VSTF development, human and computer generated behavior scripts trigger comparable human evaluation responses. We believe that PETaLS, in combination with VSTF, can become a useful tool for automatic animation of virtual characters and thus provide valuable insights in such fields as neuroscience, cognitive psychology and psychophysics.}, web_url = {http://www.uni-giessen.de/cms/fbz/fb05/germanistik/iprof/asclhome/tacos2011/prog}, event_name = {21. Tagung der Computerlinguistik Studierenden (TaCoS 2011)}, event_place = {Giessen, Germany}, state = {published}, author = {Volkova EP{evolk}{Department Human Perception, Cognition and Action}} } @Conference{ Dodds2011, title = {Telecommunication in Virtual Reality with Self-animated Avatars}, year = {2011}, month = {6}, web_url = {http://beaming-eu.org/beaming2011}, event_name = {BEAMING 2011 Workshop: Real Actions in Virtual Environments (RAVE 2011)}, event_place = {Barcelona, Spain}, state = {published}, author = {Dodds TJ{dodds}{Department Human Perception, Cognition and Action}} } @Conference{ Pretto2012_2, title = {Roll rate thresholds and perceived realism in driving simulation}, year = {2011}, month = {5}, day = {18}, event_name = {5th Human Centered Motion Cueing Workshop}, event_place = {Göteborg, Sweden}, state = {published}, author = {Pretto P{pretto}{Department Human Perception, Cognition and Action}} } @Conference{ Masone2011, title = {Mechanical Design and Control of the New 7-DOF CyberMotion Simulator}, year = {2011}, month = {5}, web_url = {http://www.vti.se/templates/Page____16117.aspx}, event_name = {5th Human Centered Motion Cueing Workshop at VTI}, event_place = {Göteborg, Sweden}, state = {published}, author = {Masone C{masone}{Department Human Perception, Cognition and Action}} } @Conference{ WallravenC2011, title = {Non-accidental properties determine object exploration patterns}, year = {2011}, month = {5}, pages = {1-2}, file_url = {fileadmin/user_upload/files/publications/2011/ICCNS-2011-Wallraven.pdf}, web_url = {http://cns.bu.edu/cns-meeting/2011conference.html}, event_name = {15th International Conferece on Cognitive and Neural Systems (ICCNS 2011)}, event_place = {Boston, MA, USA}, state = {published}, author = {Wallraven C{walli}{Department Human Perception, Cognition and Action} and Chuang L{chuang}{Department Human Perception, Cognition and Action}} } @Conference{ RobuffoGiordano2011, title = {Towards Aerial Telerobotics: Enabling human operators to bilaterally control single/multiple UAVs for accomplishing remote tasks}, year = {2011}, month = {4}, abstract = {In our research group, we study new ways to interface humans and remote (multi-)robot systems in an effective way by adopting a "shared control" perspective. Indeed, it is clear that humans, on one side, have higher cognitive skills and superior situational awareness while robots, on the other side, possess higher versatility, reliability and motion accuracy. It is then interesting to study what is the best combination between level of autonomy expected in the robots, and best sensory feedback and control leverages needed by the human users to create an effective interaction. A good example that illustrates this philosophy is probably given by the telepresence/telerobotics scenarios: exploit remote robot(s) as an extension, or even an augmentation, of the humans' senses and actions. In this talk, we will review some of the research activities that our group is performing in this context. We will focus on the use of vestibular (self-motion) and/or force-feedback feedback in interfacing a human operator with remote UAVs. A particular attention will be given to the case of force-feedback teleoperation of multiple UAVs. Indeed, this situation imposes several challenges: since the human operator cannot directly control multiple remote agents, high level of autonomy must be demanded to the UAVs. Also, from a technical point of view, establishing a teleoperation channel between a single master and multiple remote slaves is nontrivial and requires special care. A discussion on longer-term research research directions will be presented at the end of the talk.}, web_url = {http://people.mech.kuleuven.be/~u0063509/euRoboticsForum/}, event_name = {euRobotics Forum: UAV Workshop}, event_place = {Västeras, Sweden}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ BulthoffN2011, title = {myCopter: Enabling Technologies for Personal Aerial Transportation Systems}, year = {2011}, month = {3}, day = {31}, file_url = {fileadmin/user_upload/files/publications/2011/Aerodays-2011-Buelthoff.pdf}, web_url = {http://www.aerospaceforum.org/PHP/noticias.php?id=76}, event_name = {Sixth European Aerodays 2011}, event_place = {Madrid, Spain}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Nieuwenhuizen F{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}} } @Conference{ Curio2011, title = {Perceptual Graphics: Revealing the Algorithms of Perception}, year = {2011}, month = {3}, event_name = {University of Southern California, Institute of Creative Technologies (ICT)}, event_place = {Los Angeles, CA, USA}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}} } @Conference{ Breidt2011, title = {Robust Semantic Analysis by Synthesis of 3D Facial Motion}, year = {2011}, month = {3}, event_name = {University of Southern California, Institute of Creative Technologies (ICT)}, event_place = {Los Angeles, CA, USA}, state = {published}, author = {Breidt M{mbreidt}{Department Human Perception, Cognition and Action}} } @Conference{ Soyka2011, title = {Measuring and modeling changes of direction detection thresholds for different acceleration profiles}, year = {2011}, month = {2}, abstract = {In the absence of vision, the perceived direction of translational self motion is largely governed by signals originating from the otoliths. Although it has been shown that direction detection thresholds depend on the frequency of the motion stimulus, the influence of the actual time course of the motion has not been thoroughly investigated. The goal of our study was to measure, model and predict vestibular direction detection thresholds for different motion profiles in the horizontal plane. Three types of acceleration profiles (sinusoidal, trapezoidal and triangular) were tested for three different durations (1.5s, 2.36s and 5.86s). The lowest thresholds were found for trapezoidal profiles and the highest for triangular profiles. The measurements are further explained by a model based on a transfer function which is able to predict direction detection thresholds for all types of acceleration profiles. Since previous models were only able to describe thresholds for sinusoidal profiles, our modeling approach represents an important advancement.}, file_url = {fileadmin/user_upload/files/publications/2011/MüTüZü_Abstract.pdf}, event_name = {21. Oculomotor Meeting MüTüZü}, event_place = {München, Germany}, state = {published}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}} } @Conference{ Bulthoff2011, title = {What can computer scientists learn from cognitive scientists?}, year = {2011}, month = {1}, day = {11}, file_url = {fileadmin/user_upload/files/publications/2011/SDCI-2011.pdf}, event_name = {Symposium “Defining Cognitive Informatics”}, event_place = {Wien, Austria}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Book{ 5772, title = {Dynamic Faces: Insights from Experiments and Computation}, year = {2010}, month = {10}, pages = {288}, abstract = {The recognition of faces is a fundamental visual function with importance for social interaction and communication. Scientific interest in facial recognition has increased dramatically over the last decade. Researchers in such fields as psychology, neurophysiology, and functional imaging have published more than 10,000 studies on face processing. Almost all of these studies focus on the processing of static pictures of faces, however, with little attention paid to the recognition of dynamic faces, faces as they change over time—a topic in neuroscience that is also relevant for a variety of technical applications, including robotics, animation, and human-computer interfaces. This volume offers a state-of-the-art, interdisciplinary overview of recent work on dynamic faces from both biological and computational perspectives. The chapters cover a broad range of topics, including the psychophysics of dynamic face perception, results from electrophysiology and imaging, clinical deficits in patients with impairments of dynamic face processing, and computational models that provide insights about the brain mechanisms for the processing of dynamic faces. The book offers neuroscientists and biologists an essential reference for designing new experiments, and provides computer scientists with knowledge that will help them improve technical systems for the recognition, processing, synthesizing, and animating of dynamic faces.}, file_url = {/fileadmin/user_upload/files/publications/BookMITPressDraft_5772[0].pdf}, web_url = {http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=12290}, publisher = {MIT Press}, address = {Cambridge, MA, USA}, state = {published}, ISBN = {978-0-262-01453-3}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Giese MA{giese}} } @Book{ Vitello2010, title = {Perception of moving tactile stimuli}, year = {2010}, pages = {124}, web_url = {http://www.logos-verlag.de/cgi-bin/buch/isbn/2647}, publisher = {Logos-Verlag}, address = {Berlin, Germany}, series = {MPI Series in Biological Cybernetics ; 25}, state = {published}, ISBN = {978-3-8325-2647-4}, author = {Vitello MP{vitello}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}} } @Article{ 6688, title = {An illusion you can sink your teeth into: Haptic cues modulate the perceived freshness and crispness of pretzels}, journal = {Perception}, year = {2010}, month = {12}, volume = {39}, number = {12}, pages = {1684-1686}, abstract = {Eating is a multisensory experience involving more than simply the oral sensation of the taste and smell of foods. It has been shown that the way foods look, sound, and feel like in the mouth all affect food perception. The influence of haptic information available when handling food is relatively unknown. In this study, blindfolded participants bit-into fresh or stale pretzels while rating their freshness-staleness and crispness-softness. Information provided to the hand was either congruent (whole pretzel fresh or stale) or incongruent (half pretzel fresh, half stale) with what was presented to the mouth. The results demonstrate that the perception of both freshness and crispness were systematically altered when incongruent information was provided: bit-into fresh pretzel-tips were perceived as staler and softer when a stale pretzel-tip was held in the hand and vice versa. Haptic information available when handling food thus plays a significant role in modulating food perception.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=p6784}, state = {published}, DOI = {10.1068/p6784}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}} } @Article{ 6128, title = {New method to measure end-to-end delay of virtual reality}, journal = {Presence: Teleoperators and Virtual Environments}, year = {2010}, month = {12}, volume = {19}, number = {6}, pages = {569-584}, abstract = {A virtual reality (VR) system tracks one or more objects to generate the depiction of a virtual environment from the user's vantage point. No system achieves this instantaneously: changes in the depicted virtual environment are delayed from changes in the position of the objects being tracked. In this paper, a method is proposed to quantify this time difference, the end-to-end delay of the VR system. Two light-sensing devices and two luminance gradients are used to simultaneously encode the position of one tracked object and its virtual counterpart. One light-sensing device is attached to the tracked object and it captures light from the gradient in the physical environment. The other device captures light from the gradient in the virtual environment. A measurement is obtained by moving the tracked object repetitively (by hand) across the gradient. The end-to-end delay is the asynchrony between the signals generated by the two light-sensing devices. The results collected with oscillatory movements performed at different frequencies indicate that for some VR systems, the end-to-end delay might not be constant but could vary as a function of the oscillation frequency.}, file_url = {fileadmin/user_upload/files/publications/DiLuca_presence_6128.pdf}, web_url = {http://www.mitpressjournals.org/doi/pdf/10.1162/pres_a_00023}, web_url2 = {http://www.kyb.tuebingen.mpg.de/bu/people/max/}, state = {published}, DOI = {10.1162/pres_a_00023}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}} } @Article{ 6965, title = {How Are Lateral Chromatic Interactions Computed from Cone Signals?}, journal = {Neural Computation}, year = {2010}, month = {11}, volume = {22}, number = {11}, pages = {2763-2784}, abstract = {A small gray test field superimposed on a large colored background appears tinted in a color complementary to that of the surround. We tested the hypothesis whether photoreceptor sensitivity in the test field is altered in the presence of a colored surround. We investigated this effect using dichoptic viewing conditions. With the left eye, subjects viewed a small gray target superimposed on a large colored background. The right eye saw a gray target superimposed on a large gray background. When the two images were fused, observers perceived one homogeneous background and two targets. Observers matched the color of the target seen by the right eye to that seen by the left eye. A modified two-stage model for chromatic induction assuming that both receptor and postreceptor mechanisms contribute to the shift in color was fitted to the matched settings. We find that the dichoptic viewing effects presented here are well explained by an approximately equal contribution of receptor and postreceptor processes to the perceived shift in color.}, web_url = {http://www.mitpressjournals.org/doi/pdf/10.1162/NECO_a_00025}, state = {published}, DOI = {10.1162/NECO_a_00025}, author = {Wehrhahn C{wehrhahn} and Teufel H{teufel}{Department Human Perception, Cognition and Action}} } @Article{ 5625, title = {Combination and Integration in the Perception of Visual-Haptic Compliance Information}, journal = {IEEE Transactions On Haptics}, year = {2010}, month = {10}, volume = {3}, number = {4}, pages = {234-244}, abstract = {The compliance of a material can be conveyed through mechanical interactions in a virtual environment and perceived through both visual and haptic cues.We investigated this basic aspect of perception. In two experiments subjects performed compliance discriminations, and the mean perceptual estimate (PSE) and and the perceptual standard deviation (proportional to JND) were derived from psychophysical functions. Experiment 1 supported a model in which each modality acted independently to produce a compliance estimate, and the two estimates were then integrated to produce an overall value. Experiment 2 tested three mathematical models of the integration process. The data ruled out exclusive reliance on the more reliable modality and stochastic selection of one modality. Instead the results supported an integration process that constitutes a weighted summation of two random variables, which are defined by the single modality estimates. The model subsumes optimal fusion but provided valid predictions also if the weights were not optimal. Weights were optimal (i.e., minimized variance) when vision and haptic inputs were congruent, but not when they were incongruent.}, web_url = {http://doi.ieeecomputersociety.org/10.1109/TOH.2010.9}, state = {published}, DOI = {10.1109/TOH.2010.9}, author = {Kuschel M, Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Buss M and Klatzky RL{bobby}} } @Article{ 6441, title = {The Thatcher illusion in humans and monkeys}, journal = {Proceedings of the Royal Society of London B}, year = {2010}, month = {10}, volume = {277}, number = {1696}, pages = {2973-2981}, abstract = {Primates possess the remarkable ability to differentiate faces of group members and to extract relevant information about the individual directly from the face. Recognition of conspecific faces is achieved by means of holistic processing, i.e. the processing of the face as an unparsed, perceptual whole, rather than as the collection of independent features (part-based processing). The most striking example of holistic processing is the Thatcher illusion. Local changes in facial features are hardly noticeable when the whole face is inverted (rotated 180°), but strikingly grotesque when the face is upright. This effect can be explained by a lack of processing capabilities for locally rotated facial features when the face is turned upside down. Recently, a Thatcher illusion was described in the macaque monkey analogous to that known from human investigations. Using a habituation paradigm combined with eye tracking, we address the critical follow-up questions raised in the aforementioned study to show the Thatch er illusion as a function of the observer‘s species (humans and macaques), the stimulus‘ species (humans and macaques) and the level of perceptual expertise (novice, expert).}, web_url = {http://rspb.royalsocietypublishing.org/content/early/2010/05/13/rspb.2010.0438.full.pdf+html}, state = {published}, DOI = {10.1098/rspb.2010.0438}, author = {Dahl CD{dahl}{Department Human Perception, Cognition and Action}{Department Physiology of Cognitive Processes}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Article{ 6084, title = {User-based evaluation of data-driven haptic rendering}, journal = {Transactions on Applied Perception}, year = {2010}, month = {10}, volume = {8}, number = {1:7}, pages = {1-23}, abstract = {In this article, the data-driven haptic rendering approach presented in our earlier work is assessed. The approach relies on recordings from real objects from which a data-driven model is derived that captures the haptic properties of the object. We conducted two studies. In the first study, the Just Noticeable Difference (JND) for small forces, as encountered in our set-up, was determined. JNDs were obtained both for active and passive user interaction. A conservative threshold curve was derived that was then used to guide the model generation in the second study. The second study examined the achievable rendering fidelity for two objects with different stiffnesses. Subjects directly compared data-driven virtual feedback with the real objects. Results indicated that it is crucial to include dynamic material effects to achieve haptic feedback that cannot be distinguished from real objects. Results also showed that the fidelity is considerably decreased for stiffer objects due to limits of the display hardware.}, web_url = {http://portal.acm.org/citation.cfm?id=1857900}, state = {published}, DOI = {10.1145/1857893.1857900}, author = {H\"over R, Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Harders M} } @Article{ 6752, title = {Alterations in choice behavior by manipulations of world model}, journal = {Proceedings of the National Academy of Sciences of the Unites States of America}, year = {2010}, month = {9}, volume = {107}, number = {37}, pages = {16401-16406}, abstract = {How to compute initially unknown reward values makes up one of the key problems in reinforcement learning theory, with two basic approaches being used. Model-free algorithms rely on the accumulation of substantial amounts of experience to compute the value of actions, whereas in model-based learning, the agent seeks to learn the generative process for outcomes fromwhich the value of actions can be predicted. Here we show that (i) “probability matching”— a consistent example of suboptimal choice behavior seen in humans —occurs in an optimal Bayesian model-based learner using a max decision rule that is initialized with ecologically plausible, but incorrect beliefs about the generative process for outcomes and (ii) human behavior can be strongly and predictably altered by the presence of cues suggestive of various generative processes, despite statistically identical outcome generation. These results suggest human decision making is rational and model based and not consistent with model-free learning.}, web_url = {http://www.pnas.org/content/107/37/16401.full.pdf+html}, state = {published}, DOI = {10.1073/pnas.1001709107}, author = {Green CS, Benson C, Kersten D{kersten}{Department Human Perception, Cognition and Action} and Schrater P} } @Article{ 6783, title = {Bayesian integration of visual and vestibular signals for heading}, journal = {Journal of Vision}, year = {2010}, month = {9}, volume = {10}, number = {11}, pages = {1-13}, abstract = {Self-motion through an environment involves a composite of signals such as visual and vestibular cues. Building upon previous results showing that visual and vestibular signals combine in a statistically optimal fashion, we investigated the relative weights of visual and vestibular cues during self-motion. This experiment was comprised of three experimental conditions: vestibular alone, visual alone (with four different standard heading values), and visual–vestibular combined. In the combined cue condition, inter-sensory conflicts were introduced (Δ = ±6° or ±10°). Participants performed a 2-interval forced choice task in all conditions and were asked to judge in which of the two intervals they moved more to the right. The cue-conflict condition revealed the relative weights associated with each modality. We found that even when there was a relatively large conflict between the visual and vestibular cues, participants exhibited a statistically optimal reduction in variance. On the other hand, we found that the pattern of results in the unimodal conditions did not predict the weights in the combined cue condition. Specifically, visual–vestibular cue combination was not predicted solely by the reliability of each cue, but rather more weight was given to the vestibular cue.}, web_url = {http://www.journalofvision.org/content/10/11/23.full.pdf+html}, state = {published}, DOI = {10.1167/10.11.23}, EPUB = {23}, author = {Butler JS{butler}{Department Human Perception, Cognition and Action}, Smith ST{stusmith}, Campos JL{camposjl}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 6500, title = {Learning to use an invisible visual signal for perception}, journal = {Current Biology}, year = {2010}, month = {9}, volume = {20}, number = {20}, pages = {1860-1863}, abstract = {How does the brain construct a percept from sensory signals? One approach to this fundamental question is to investigate perceptual learning as induced by exposure to statistical regularities in sensory signals [1–7]. Recent studies showed that exposure to novel correlations between sensory signals can cause a signal to have new perceptual effects [2, 3]. In those studies, however, the signals were clearly visible. The automaticity of the learning was therefore difficult to determine. Here we investigate whether learning of this sort, which causes new effects on appearance, can be low level and automatic by employing a visual signal whose perceptual consequences were made invisible—a vertical disparity gradient masked by other depth cues. This approach excluded high-level influences such as attention or consciousness. Our stimulus for probing perceptual appearance was a rotating cylinder. During exposure, we introduced a new contingency between the invisible signal and the rotation direction of the cylinder. When subsequently presenting an ambiguously rotating version of the cylinder, we found that the invisible signal influenced the perceived rotation direction. This de monstrates that perception can rapidly undergo ‘‘structure learning’’ by automatically picking up novel contingencies between sensory signals, thus automatically recruiting signals for novel uses during the construction of a percept.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6VRT-51618H5-7-G&_cdi=6243&_user=29041&_pii=S0960982210011656&_origin=search&_coverDate=10%2F26%2F2010&_sk=999799979&view=c&wchp=dGLbVzW-zSkWA&md5=ade64c780791a37d8086effaeda3b349&ie=/sdarticle.pdf}, state = {published}, DOI = {10.1016/j.cub.2010.09.047}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Ernst M{marc}{Research Group Multisensory Perception and Action} and Backus B{backus}} } @Article{ 6643, title = {Visual and Haptic Perceptual Spaces Show High Similarity in Humans}, journal = {Journal of Vision}, year = {2010}, month = {9}, volume = {10}, number = {11:2}, pages = {1-20}, abstract = {In this study, we show that humans form highly similar perceptual spaces when they explore complex objects from a parametrically defined object space in the visual and haptic domains. For this, a three-dimensional parameter space of well-defined, shell-like objects was generated. Participants either explored two-dimensional pictures or three-dimensional, interactive virtual models of these objects visually, or they explored three-dimensional plastic models haptically. In all cases, the task was to rate the similarity between two objects. Using these similarity ratings and multidimensional scaling (MDS) analyses, the perceptual spaces of the different modalities were then analyzed. Looking at planar configurations within this three-dimensional object space, we found that active visual exploration led to a highly similar perceptual space compared to passive exploration, showing that participants were able to reconstruct the complex parameter space already from two-dimensional pictures alone. Furthermore, we found that visual and haptic perceptual spaces had virtually identical topology compared to that of the physical stimulus space. Surprisingly, the haptic modality even slightly exceeded the visual modality in recovering the topology of the complex object space when the whole three-dimensional space was explored. Our findings point to a close connection between visual and haptic object representations and demonstrate the great degree of fidelity with which haptic shape processing occurs.}, web_url = {http://www.journalofvision.org/content/10/11/2.full.pdf+html}, state = {published}, DOI = {10.1167/10.11.2}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 6780, title = {Audiovisual interactions in binocular rivalry}, journal = {Journal of Vision}, year = {2010}, month = {8}, volume = {10}, number = {10:27}, pages = {1-15}, abstract = {When the two eyes are presented with dissimilar images, human observers report alternating percepts—a phenomenon coined binocular rivalry. These perceptual fluctuations reflect competition between the two visual inputs both at monocular and binocular processing stages. Here we investigated the influence of auditory stimulation on the temporal dynamics of binocular rivalry. In three psychophysics experiments, we investigated whether sounds that provide directionally congruent, incongruent, or non-motion information modulate the dominance periods of rivaling visual motion percepts. Visual stimuli were dichoptically presented random-dot kinematograms (RDKs) at different levels of motion coherence. The results show that directional motion sounds rather than auditory input per se influenced the temporal dynamics of binocular rivalry. In all experiments, motion sounds prolonged the dominance periods of the directionally congruent visual motion percept. In contrast, motion sounds abbreviated the suppression periods of the directionally congruent visual motion percepts only when they competed with directionally incongruent percepts. Therefore, analogous to visual contextual effects, auditory motion interacted primarily with consciously perceived visual input rather than visual input suppressed from awareness. Our findings suggest that auditory modulation of perceptual dominance times might be established in a top-down fashion by means of feedback mechanisms.}, web_url = {http://www.journalofvision.org/content/10/10/27.full.pdf+html}, state = {published}, DOI = {10.1167/10.10.27}, author = {Conrad V{conrad}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging}, Bartels A{abartels}{Department Physiology of Cognitive Processes}, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Article{ 6001, title = {Crossing the hands is more confusing for females than males}, journal = {Experimental Brain Research}, year = {2010}, month = {7}, volume = {204}, number = {3}, pages = {431-446}, abstract = {A conflict between an egocentric and an external reference frame can be highlighted by examining the marked deficit observed with tactile temporal order judgments (TOJ) when the hands are crossed. The anecdotally-reported large individual differences in the magnitude of this crossed-hands deficit were explored here by testing a large group of participants (48; 24 female). Given that females have been shown to be more visually dependent than males in the potentially related rod-and-frame test (RFT), we hypothesized that females would show a larger influence of the external reference frame (i.e., a larger crossed-hands deficit). As predicted, female participants produced larger tactile TOJ deficits compared to our male participants. We also administered the RFT in these participants with hands crossed and uncrossed. Crossing the hands increased the effect of the frame in the RFT, more so for females than males, further highlighting the potential difference in the way that each sex accommodates reference frame c onflicts. Finally, examining the relation between the two tasks revealed a significant correlation, with larger frame effects associated with larger crossed-hands TOJ deficits, but this only held for males. We speculate that sex-specific differences in multisensory processing and spatial ability may explain why females are less able to disambiguate a crossed-hands posture than are males.}, web_url = {http://www.springerlink.com/content/1402277141284614/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-010-2268-5}, author = {Cadieux ML, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action} and Shore DI} } @Article{ 6429, title = {Spatial and temporal aspects of navigation in two neurological patients}, journal = {NeuroReport}, year = {2010}, month = {7}, volume = {21}, number = {10}, pages = {685-689}, abstract = {We present two cases (A.C. and W.J.) with navigation problems resulting from parieto-occipital right hemisphere damage. For both the cases, performance on the neuropsychological tests did not indicate specific impairments in spatial processing, despite severe subjective complaints of spatial disorientation. Various aspects of navigation were tested in a new virtual reality task, the Virtual Tübingen task. A double dissociation between spatial and temporal deficits was found; A.C. was impaired in route ordering, a temporal test, whereas W.J. was impaired in scene recognition and route continuation, which are spatial in nature. These findings offer important insights in the functional and neural architecture of navigation.}, web_url = {http://ovidsp.tx.ovid.com/sp-3.2.3a/ovidweb.cgi?&S=PPLCFPGNELDDPDDMNCDLPCOBBDLMAA00&WebLinkReturn=Full+Text%3dL%7cS.sh.15.17%7c0%7c00001756-201007140-00004&PDFLink=FPDDNCOBPCDMEL00%7c%2ffs047%2fovft%2flive%2fgv024%2f00001756%2f00001756-201007140-00004&PDF}, state = {published}, DOI = {10.1097/WNR.0b013e32833aea78}, author = {van der Ham IJM, van Zandvoort MJE, Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Bosch SE, Kant N and Postma A} } @Article{ 6447, title = {Estimation of environmental force for the haptic interface of robotic surgery}, journal = {International Journal of Medical Robotics and Computer Assisted Surgery}, year = {2010}, month = {6}, volume = {6}, number = {2}, pages = {221-230}, abstract = {Background The success of a telerobotic surgery system with haptic feedback requires accurate force-tracking and position-tracking capacity of the slave robot. The two-channel force-position control architecture is widely used in teleoperation systems with haptic feedback for its better force-tracking characteristics and superior position-tracking capacity for the maximum stability margin. This control architecture, however, requires force sensors at the end-effector of the slave robot to measure the environment force. However, it is difficult to attach force sensors to slave robots, mainly due to their large size, insulation issues and also large currents often flowing through the end-effector for incision or cautery of tissues. Methods This paper provides a method to estimate the environment force, using a function parameter matrix and a recursive least-squares method. The estimated force is used to feed back the force information to the surgeon through the control architecture without involving the force sensors. Results The simulation and experimental results verify the efficacy of the proposed method. The force estimation error is negligible and the slave device successfully tracks the position of the master device while the stability of the teleoperation system is maintained. Conclusions The developed method allows practical haptic feedback for telerobotic surgery systems in the two-channel force-position control scheme without the direct employment of force sensors at the end-effector of the slave robot.}, web_url = {http://www3.interscience.wiley.com/cgi-bin/fulltext/123410015/PDFSTART}, state = {published}, DOI = {10.1002/rcs.311}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Bhattacharjee T and Lee DY} } @Article{ 6123, title = {The Effect of Viewing a Self-Avatar on Distance Judgments in an HMD-Based Virtual Environment}, journal = {Presence: Teleoperators and Virtual Environments}, year = {2010}, month = {6}, volume = {19}, number = {3}, pages = {230-242}, abstract = {Few HMD-based virtual environment systems display a rendering of the user’s own body. Subjectively, this often leads to a sense of disembodiment in the virtual world. We explore the effect of being able to see one’s own body in such systems on an objective measure of the accuracy of one form of space perception. Using an action-based response measure, we found that participants who explored near space while seeing fully-articulated and tracked visual representation of themselves subsequently made more accurate judgments of absolute egocentric distance to locations ranging from 4m to 6m away from where they were standing than did participants who saw no avatar. A non-animated avatar also improved distance judgments, but by a lesser amount. Participants who viewed either animated or static avatars positioned 3m in front of their own position made subsequent distance judgments with similar accuracy to the participants who viewed the equivalent animated or static avatar positioned at their own location. We discuss the implications of these results on theories of embodied perception in virtual environments.}, web_url = {http://www.mitpressjournals.org/doi/pdf/10.1162/pres.19.3.230}, state = {published}, DOI = {10.1162/pres.19.3.230}, author = {Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, Creem-Regehr SH, Thompson WB{wthompson} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 6318, title = {The quick and the dead: when reaction beats intention}, journal = {Proceedings of the Royal Society of London B}, year = {2010}, month = {6}, volume = {277}, number = {1688}, pages = {1667-1674}, abstract = {Everyday behaviour involves a trade-off between planned actions and reaction to environmental events. Evidence from neurophysiology, neurology and functional brain imaging suggests different neural bases for the control of different movement types. Here we develop a behavioural paradigm to test movement dynamics for intentional versus reaction movements and provide evidence for a ‘reactive advantage’ in movement execution, whereby the same action is executed faster in reaction to an opponent. We placed pairs of participants in competition with each other to make a series of button presses. Within-subject analysis of movement times revealed a 10 per cent benefit for reactive actions. This was maintained when opponents performed dissimilar actions, and when participants competed against a computer, suggesting that the effect is not related to facilitation produced by action observation. Rather, faster ballistic movements may be a general property of reactive motor control, potentially providing a useful means of promoting survival.}, web_url = {http://rspb.royalsocietypublishing.org/content/early/2010/01/28/rspb.2009.2123.full.pdf+html}, state = {published}, DOI = {10.1098/rspb.2009.2123}, author = {Welchman AE{aew}{Department Human Perception, Cognition and Action}, Stanley J, Schomers MR{schomers}{Department Human Perception, Cognition and Action}, Miall RC and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 5262, title = {Inconsistency of perceived 3D shape}, journal = {Vision Research}, year = {2010}, month = {5}, volume = {50}, number = {16}, pages = {1519-1531}, abstract = {Perceived three-dimensional shape can be systematically distorted by altering viewing conditions. Here we investigate whether such distortions are inconsistent or congruent among different surface properties (relative depth, orientation, and curvature). Participants matched two surfaces defined by different types of visual information (motion parallax, texture, or shading). Judgments of different surface properties elicited qualitatively different patterns of distortions. Adding multiple sources of information did not eliminate inconsistencies. This result indicates that 3D shape perception is not based on Euclidean representation. Moreover, models of cue integration that assume interpretation of information prior to fusion cannot account for such findings.}, web_url = {http://www.sciencedirect.com/science?_ob=DownloadURL&_method=confirm&_uoikey=B6T0W-502GH0S-1&count=1&_docType=FLA&_acct=C000003178&_version=1&_userid=29041&md5=141af7753dd76581d5bb77199c705c3e}, state = {published}, DOI = {10.1016/j.visres.2010.05.006}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Domini F and Caudek C} } @Article{ 6864, title = {Live face-to-face interaction during fMRI: A new tool for social cognitive neuroscience}, journal = {NeuroImage}, year = {2010}, month = {5}, volume = {50}, number = {4}, pages = {1639-1647}, abstract = {Cooperative social interaction is critical for human social development and learning. Despite the importance of social interaction, previous neuroimaging studies lack two fundamental components of everyday face-to-face interactions: contingent responding and joint attention. In the current studies, functional MRI data were collected while participants interacted with a human experimenter face-to-face via live video feed as they engaged in simple cooperative games. In Experiment 1, participants engaged in a live interaction with the experimenter (“Live”) or watched a video of the same interaction (“Recorded”). During the “Live” interaction, as compared to the Recorded conditions, greater activation was seen in brain regions involved in social cognition and reward, including the right temporoparietal junction (rTPJ), anterior cingulate cortex (ACC), right superior temporal sulcus (rSTS), ventral striatum, and amygdala. Experiment 2 isolated joint attention, a critical component of social interaction. Part icipants either followed the gaze of the live experimenter to a shared target of attention (“Joint Attention”) or found the target of attention alone while the experimenter was visible but not sharing attention (“Solo Attention”). The right temporoparietal junction and right posterior STS were differentially recruited during Joint, as compared to Solo, attention. These findings suggest the rpSTS and rTPJ are key regions for both social interaction and joint attention. This method of allowing online, contingent social interactions in the scanner could open up new avenues of research in social cognitive neuroscience, both in typical and atypical populations.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6WNP-4Y70C6H-6-K&_cdi=6968&_user=29041&_pii=S1053811910000741&_origin=search&_coverDate=05%2F01%2F2010&_sk=999499995&view=c&wchp=dGLbVtz-zSkzk&md5=63fc5d75dc080b797ba36d6b05edc40f&ie=/sdarticle.pdf}, state = {published}, DOI = {10.1016/j.neuroimage.2010.01.052}, author = {Redcay E, Dodell-Feder D, Pearrow MJ, Mavros PL, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}, Gabrieli JDE and Saxe R} } @Article{ 6397, title = {Modulation of visual neurons in the superior temporal sulcus by audio-visual congruency}, journal = {Frontiers in Integrative Neuroscience}, year = {2010}, month = {4}, volume = {4}, number = {10}, pages = {1-8}, abstract = {Our ability to identify or recognize visual objects is often enhanced by evidence provided by other sensory modalities. Yet, where and how visual object processing benefits from the information received by the other senses remains unclear. One candidate region is the temporal lobe, which features neural representations of visual objects, and in which previous studies have provided evidence for multisensory influences on neural responses. In the present study we directly tested whether visual representations in the lower bank of the superior temporal sulcus (STS) benefit from acoustic information. To this end, we recorded neural responses in alert monkeys passively watching audio&amp;amp;amp;amp;amp;#8208;visual scenes, and quantified the impact of simultaneously presented sounds on responses elicited by the presentation of naturalistic visual scenes. Using methods of stimulus decoding and information theory, we then asked whether the responses of STS neurons become more reliable and informative in multisensory contexts. Our results demonstrate that STS neurons are indeed sensitive to the modality composition of the sensory stimulus and show that both response timing and amplitude are affected by simultaneously presented sounds. Importantly, information provided by STS neurons’ responses about the particular visual stimulus being presented was highest during congruent audio&amp;amp;amp;amp;amp;#8208;visual and unimodal visual stimulation, but was reduced during incongruent bimodal stimulation. Together, these findings demonstrate that higher visual representations in the STS not only convey information about the visual input but depend on and reflect also the information acquired by other sensory modalities.}, file_url = {/fileadmin/user_upload/files/publications/dahl_kayser2010_6397[0].pdf}, web_url = {http://www.frontiersin.org/neuroscience/integrativeneuroscience/paper/10.3389/fnint.2010.00010/}, state = {published}, DOI = {10.3389/fnint.2010.00010}, author = {Dahl CD{dahl}{Department Human Perception, Cognition and Action}{Department Physiology of Cognitive Processes}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes} and Kayser C{kayser}{Department Physiology of Cognitive Processes}{Research Group Physiology of Sensory Integration}} } @Article{ 6555, title = {Transformation Direction Influences Shape-Similarity Judgments}, journal = {Psychological Science}, year = {2010}, month = {4}, volume = {20}, number = {4}, pages = {447-454}, abstract = {Three experiments provide evidence that the perceived similarity between two images is systematically affected by the inherent direction of a transformation that links the two. Participants were shown short animations morphing one object into another from the same basic category. They were then asked to make directional similarity judgments (‘‘How similar is object A to object B?’’) for two stationary images drawn from the morph continuum. Across three experiments, similarity ratings for identical comparisons were higher when the reference object, B, had appeared before the comparison object, A, in the preceding morph sequence. This response to dynamic transformational sequences is in accordance with the view that similarity depends on the ease of transformation between object representations and that transformations between objects in categorization and object recognition are psychologically real.}, web_url = {http://pss.sagepub.com/content/20/4/447.full.pdf+html}, state = {published}, DOI = {10.1111/j.1467-9280.2009.02310.x}, author = {Hahn U, Close J and Graf M{grafm}{Department Human Perception, Cognition and Action}} } @Article{ 6408, title = {Attentional Networks and Biological Motion}, journal = {Psihologija}, year = {2010}, month = {3}, volume = {43}, number = {1}, pages = {5-20}, abstract = {Our ability to see meaningful actions when presented with point-light traces of human movement is commonly referred to as the perception of biological motion. While traditional explanations have emphasized the spontaneous and automatic nature of this ability, more recent findings suggest that attention may play a larger role than is typically assumed. In two studies we show that the speed and accuracy of responding to point-light stimuli is highly correlated with the ability to control selective attention. In our first experiment we measured thresholds for determining the walking direction of a masked point-light figure, and performance on a range of attention-related tasks in the same set of observers. Mask-density thresholds for the direction discrimination task varied quite considerably from observer to observer and this variation was highly correlated with performance on both Stroop and flanker interference tasks. Other components of attention, such as orienting, alerting and visual search efficiency, showed no such relationship. In a second experiment, we examined the relationship between the ability to determine the orientation of unmasked point-light actions and Stroop interference, again finding a strong correlation. Our results are consistent with previous research suggesting that biological motion processing may requite attention, and specifically implicate networks of attention related to executive control and selection.}, file_url = {/fileadmin/user_upload/files/publications/Psihologija-2010-43-5_[0].pdf}, web_url = {http://scindeks.nb.rs/journaldetails.aspx?issn=0048-5705&amp;lang=en}, state = {published}, DOI = {10.2298/PSI1001005C}, author = {Chandrasekaran C{chand}{Department Human Perception, Cognition and Action}, Turner L, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Thornton IM{ian}{Department Human Perception, Cognition and Action}} } @Article{ 6402, title = {Brain Imaging: Decoding Your Memories}, journal = {Current Biology}, year = {2010}, month = {3}, volume = {20}, number = {6}, pages = {R269-R271}, abstract = {Recent advances in neuroimaging allow mental states to be inferred from non-invasive data. In a new study, memories of complex events were successfully decoded solely from imaged activation in a memory-related brain structure.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6VRT-4YNKHPX-D-4&_cdi=6243&_user=29041&_pii=S0960982210001314&_orig=search&_coverDate=03%2F23%2F2010&_sk=999799993&view=c&wchp=dGLzVtz-zSkWz&md5=91beb337f50434cb758048e520c0abb5&ie=/sdarticle.pdf}, state = {published}, DOI = {10.1016/j.cub.2010.02.001}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action}} } @Article{ 6324, title = {Circadian Plasticity in Photoreceptor Cells Controls Visual Coding Efficiency in Drosophila melanogaster}, journal = {PLoS ONE}, year = {2010}, month = {2}, volume = {5}, number = {2}, pages = {1-10}, web_url = {http://www.plosone.org/article/fetchObjectAttachment.action;jsessionid=C6DD8E17425F484C05F0BAB5B0CBEE00?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0009217&representation=PDF}, state = {published}, DOI = {10.1371/journal.pone.0009217}, EPUB = {e9217}, author = {Barth M, Schultze M{mschultze}{Department Human Perception, Cognition and Action}, Schuster CM and Strauss R{strauss}} } @Article{ 6863, title = {RTbox: a device for highly accurate response time measurements}, journal = {Behavior Research Methods}, year = {2010}, month = {2}, volume = {42}, number = {1}, pages = {212-225}, abstract = {Although computer keyboards and mice are frequently used in measuring response times (RTs), the accuracy of these measurements is quite low. Specialized RT collection devices must be used to obtain more accurate measurements. However, all the existing devices have some shortcomings. We have developed and implemented a new, commercially available device, the RTbox, for highly accurate RT measurements. The RTbox has its own microprocessor and high-resolution clock. It can record the identities and timing of button events with high accuracy, unaffected by potential timing uncertainty or biases during data transmission and processing in the host computer. It stores button events until the host computer chooses to retrieve them. The asynchronous storage greatly simplifies the design of user programs. The RTbox can also receive and record external signals as triggers and can measure RTs with respect to external events. The internal clock of the RTbox can be synchronized with the computer clock, so the device can be used without external triggers. A simple USB connection is sufficient to integrate the RTbox with any standard computer and operating system.}, web_url = {http://lobes.usc.edu/RTbox/}, state = {published}, DOI = {10.3758/BRM.42.1.212}, author = {Li X, Liang Z, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action} and Lu Z-L} } @Article{ 6240, title = {Action observation can prime visual object recognition}, journal = {Experimental Brain Research}, year = {2010}, month = {1}, volume = {200}, number = {3-4}, pages = {251-258}, abstract = {Observing an action activates action representations in the motor system. Moreover, the representations of manipulable objects are closely linked to the motor systems at a functional and neuroanatomical level. Here, we investigated whether action observation can facilitate object recognition using an action priming paradigm. As prime stimuli we presented short video movies showing hands performing an action in interaction with an object (where the object itself was always removed from the video). The prime movie was followed by a (briefly presented) target object affording motor interactions that are either similar (congruent condition) or dissimilar (incongruent condition) to the prime action. Participants had to decide whether an object name shown after the target picture corresponds with the picture or not (picture–word matching task). We found superior accuracy for prime–target pairs with congruent as compared to incongruent actions across two experiments. Thus, action observation can facilitate recogni tion of a manipulable object typically involving a similar action. This action priming effect supports the notion that action representations play a functional role in object recognition.}, web_url = {http://springerlink.metapress.com/content/a5ph883317156381/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-009-1953-8}, author = {Helbig HB{helbig}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Steinwender J{jstein}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Graf M{grafm}{Department Human Perception, Cognition and Action} and Kiefer M} } @Article{ 6122, title = {Insights into the control of arm movement during body motion as revealed by EMG analyses}, journal = {Brain Research}, year = {2010}, month = {1}, volume = {1309}, pages = {40-52}, file_url = {/fileadmin/user_upload/files/publications/blouin2010_6122[0].pdf}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6SYR-4XKBYT9-2-N&_cdi=4841&_user=29041&_pii=S0006899309023002&_orig=search&_coverDate=01%2F14%2F2010&_sk=986909999&view=c&wchp=dGLzVtz-zSkWb&md5=a6f233d1436e229d9539e09da1dd3eea&ie=/sdarticle.pdf}, state = {published}, DOI = {10.1016/j.brainres.2009.10.063}, author = {Blouin J, Guillaud E, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}, Guerraz M and Simoneau M} } @Article{ 4179, title = {Multidimensional scaling analysis of haptic exploratory procedures}, journal = {ACM Transactions on Applied Perception}, year = {2010}, month = {1}, volume = {7}, number = {1:7}, pages = {1-17}, abstract = {Previous work in real and virtual settings has shown that the way in which we interact with objects plays a fundamental role in the way we perceive them. This article uses multidimensional scaling (MDS) analysis to further characterize and quantify the effects of using different haptic exploratory procedures (EPs) on perceptual similarity spaces. In Experiment 1, 20 participants rated similarity on a set of nine novel, 3D objects varying in shape and texture after either following their contours, laterally rubbing their centers, gripping them, or sequentially touching their tips. MDS analysis was used to recover perceptual maps of the objects and relative weights of perceptual dimensions from similarity data. Both the maps and relative weights of shape/texture properties were found to vary as a function of the EP used. In addition, large individual differences in the relative weight of shape/texture were observed. In Experiment 2, 17 of the previous participants repeated Experiment 1 after an average of 105 d ays. The same patterns of raw similarity ratings, perceptual maps, dimension weights, and individual differences were observed, indicating that perceptual similarities remained stable over time. The findings underscore the role of hand movements and individual biases in shaping haptic perceptual similarity. A framework for validating multimodal virtual displays based on the approach used in the study is also presented.}, file_url = {/fileadmin/user_upload/files/publications/expl_proc_4179[0].pdf}, web_url = {http://portal.acm.org/citation.cfm?id=1658349.1658356&coll=portal&dl=ACM,ACM&idx=J932&part=transaction&WantType=Transactions&title=TAP}, state = {published}, DOI = {10.1145/1658349.1658356}, author = {Cooke T{tmcooke}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 4199, title = {Simulating believable forward accelerations on a stewart motion platform}, journal = {ACM Transactions on Applied Perception}, year = {2010}, month = {1}, volume = {7}, number = {1:5}, pages = {1-27}, abstract = {It is still an unsolved problem how to optimally simulate self-motion using motion simulators. We investigated how a forward acceleration can be simulated as believably as possible on a hexapod motion platform equipped with a projection screen. Human participants rated the believability of brief forward accelerations. These were simulated as visual forward accelerations over a ground plane with people as size cues, presented together with brief forward surge translations and backward pitches of the platform, and synchronous random up--down movements of the camera in the visual scene and the platform. The magnitudes of all of the parameters were varied independently across trials. Even though variability between participants was high, the most believable simulation occurred when visual accelerations were combined with backward pitches of the platform, which changed the gravitoinertial vector direction approximately consistent with the visual acceleration. However, a wide range of platform pitches was accepted as believable. With high visual acceleration cues most participants reported trials as realistic even when the platform tilt rate was above vestibular canal thresholds reported in other works. Other manipulated parameters had only a mild influence on the responses. These results can be used to optimize motion-cueing algorithms for simulating linear accelerations in motion simulators.}, web_url = {http://portal.acm.org/citation.cfm?id=1658349.1658354&coll=portal&dl=ACM&idx=J932&part=transaction&WantType=Transactions&title=ACM%20Transactions%20on%20Applied%20Perception%20(TAP)&CFID=75661239&CFTOKEN=93480988}, state = {published}, DOI = {10.1145/1658349.1658354}, author = {Berger DR{berger}{Department Human Perception, Cognition and Action}, Schulte-Pelkum J{jsp}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 6035, title = {Storing upright turns: how visual and vestibular cues interact during the encoding and recalling process}, journal = {Experimental Brain Research}, year = {2010}, month = {1}, volume = {200}, number = {1}, pages = {37-49}, file_url = {/fileadmin/user_upload/files/publications/storing-upright-turn-Vidal-hhb_[0].pdf}, web_url = {http://www.springerlink.com/content/q330562617g08g31/}, state = {published}, DOI = {10.1007/s00221-009-1980-5}, author = {Vidal M{vidal}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6996, title = {Face Models from Noisy 3D Cameras}, journal = {Proceedings of the 3rd ACM SIGGRAPH Conference and Exhibition on Computer Graphics and Interactive Techniques in Asia (SIGGRAPH Asia 2010)}, year = {2010}, month = {12}, pages = {1-2}, abstract = {Affordable 3D vision is just about to enter the mass market for consumer products such as video game consoles or TV sets. Having depth information in this context is beneficial for segmentation as well as gaining robustness against illumination effects, both of which are hard problems when dealing with color camera data in typical living room situations. Several techniques compute 3D (or rather 2.5D) depth information from camera data such as realtime stereo, time-of-flight (TOF), or real-time structured light, but all produce noisy depth data at fairly low resolutions. Not surprisingly, most applications are currently limited to basic gesture recognition using the full body. In particular, TOF cameras are a relatively new and promising technology for compact, simple and fast 2.5D depth measurements. Due to the measurement principle of measuring the flight time of infrared light as it bounces off the subject, these devices have comparatively low image resolution (176 x 144 ... 320 x 240 pixels) with a high le vel of noise present in the raw data.}, web_url = {http://www.siggraph.org/asia2010/}, editor = {Cani, M.-P. , A. Sheffer}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {3rd ACM SIGGRAPH Conference and Exhibition on Computer Graphics and Interactive Techniques in Asia (SIGGRAPH Asia 2010)}, event_place = {Seoul, Korea}, state = {published}, DOI = {10.1145/1899950.1899962}, author = {Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6820, title = {Face Reality: Investigating the Uncanny Valley for virtual faces}, journal = {Proceedings of the 3rd ACM SIGGRAPH Conference and Exhibition on Computer Graphics and Interactive Techniques in Asia (SIGGRAPH Asia 2010)}, year = {2010}, month = {12}, pages = {1-2}, abstract = {The Uncanny Valley (UV) has become a standard term for the theory that near-photorealistic virtual humans often appear unintentionally erie or creepy. This UV theory was first hypothesized by robotics professor Masahiro Mori in the 1970‘s [Mori 1970] but is still taken seriously today by movie and game developers as it can stop audiences feeling emotionally engaged in their stories or games. It has been speculated that this is due to audiences feeling a lack of empathy towards the characters. With the increase in popularity of interactive drama video games (such as L.A. Noire or Heavy Rain), delivering realistic conversing virtual characters has now become very important in the real-time domain. Video game rendering techniques have advanced to a very high quality; however, most games still use linear blend skinning due to the speed of computation. This causes a mismatch between the realism of the appearance and animation, which can result in an uncanny character. Many game developers opt for a stylised rendering (such as cel-shading) to avoid the uncanny effect [Thompson 2004]. In this preliminary work, we begin to study the complex interaction between rendering style and perceived trust, in order to provide guidelines for developers for creating plausible virtual characters.}, file_url = {/fileadmin/user_upload/files/publications/SiggraphAsia2010-McDonnell_6820[0].pdf}, web_url = {http://www.siggraph.org/asia2010/}, editor = {Cani, M.-P. , A. Sheffer}, publisher = {ACM Press}, address = {Nw York, NY, USA}, event_name = {3rd ACM SIGGRAPH Conference and Exhibition on Computer Graphics and Interactive Techniques in Asia (SIGGRAPH Asia 2010)}, event_place = {Seoul, Korea}, state = {published}, DOI = {10.1145/1899950.1899991}, author = {McDonnell R and Breidt M{mbreidt}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6676, title = {On optimal cooperative patrolling}, journal = {Proceedings of the 49th IEEE Conference on Decision and Control (CDC 2010)}, year = {2010}, month = {12}, pages = {7153-7158}, abstract = {This work considers the problem of designing optimal multi-agent trajectories to patrol an environment. In both civil and military applications it is of increasing importance to instruct a team of autonomous agents to accomplish repetitive tasks, such as the monitoring of strategic regions or the detection of life threatening situations. As performance criterion for optimal patrolling we minimize the worst-case time gap between any two visits of an environment location. We characterize the computational complexity of the trajectory design (patrolling) problem with respect to the environment topology and to the number of robots to be employed in the surveillance task. Even though the patrolling problem is generally NP-hard, we identify particular cases that are solvable efficiently, and we describe optimal patrolling trajectories. Finally, we present a heuristic with performance guarantee, and an 8-approximation algorithm to solve the NP-hard patrolling problem.}, file_url = {/fileadmin/user_upload/files/publications/0819_6676[1].pdf}, web_url = {http://www.ieeecss.org/CAB/conferences/cdc2010/index.php}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {49th IEEE Conference on Decision and Control (CDC 2010)}, event_place = {Atlanta, GA, USA}, state = {published}, ISBN = {978-1-4244-7745-6}, DOI = {10.1109/CDC.2010.5717873}, author = {Pasqualetti F, Franchi A{antonio}{Department Human Perception, Cognition and Action} and Bullo F} } @Inproceedings{ 6675, title = {Probabilistic mutual localization in multi-agent systems from anonymous position measures}, journal = {Proceedings of the 49th IEEE Conference on Decision and Control (CDC 2010)}, year = {2010}, month = {12}, pages = {6534-6540}, abstract = {Recent research on multi-agent systems has produced a plethora of decentralized controllers that implicitly assume various degrees of agent localization. However, many practical arrangements commonly taken to allow and achieve localization imply some form of centralization, from the use of physical tagging to allow the identification of the single agent to the adoption of global positioning systems based on cameras or GPS. These devices clearly decrease the system autonomy and range of applicability, and should be avoided if possible. Following this guideline, this work addresses the mutual localization problem with anonymous relative position measures, presenting a robust solution based on a probabilistic framework. The proposed localization system exhibits higher accuracy and lower complexity (O(n2)) than our previous method [1]. Moreover, with respect to more conventional solutions that could be conceived on the basis of the current literature, our method is theoretically suitable for tasks requiring frequent, manyto- many encounters among agents (e.g., formation control, cooperative exploration, multiple-view environment sensing). The proposed localization system has been validated by means of an extensive experimental study.}, file_url = {/fileadmin/user_upload/files/publications/0872_6675[0].pdf}, web_url = {http://www.ieeecss.org/CAB/conferences/cdc2010/index.php}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {49th IEEE Conference on Decision and Control (CDC 2010)}, event_place = {Atlanta, GA, USA}, state = {published}, ISBN = {978-1-4244-7745-6}, DOI = {10.1109/CDC.2010.5717905}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}, Stegagno P and Oriolo G} } @Inproceedings{ 6842, title = {Augmented Human-Machine Interface: Providing a Novel Haptic Cueing to the Tele-Operator}, journal = {Proceedings of the 3rd Workshop for Young Researchers on Human-Friendly Robotics (HFR 2010)}, year = {2010}, month = {10}, pages = {1-2}, abstract = {The sense of telepresence is very important in teleoperation environments in which the operator is physically separated from the vehicle. Extending the visual interface to a multi-sensory interface could allow the teleoperator to better perceive information of the environment and its constraints. The use of force feedback would complement the visual information through the sense of touch. This paper focuses on a novel concept of haptic cueing developed in order to optimize the performance of a teleoperator and to improve the human-machine interfaces. A first experiment showed the effectiveness of the newly developed haptic cueing, the Indirect Haptic Aiding, with respect to visual cueing only. In a second experiment, we compared the IHA to an existing haptic concept, the Direct Haptic Aiding. The problem of wind gust rejection in Remotely Piloted Vehicles is used as test bench. The results show the effectiveness of both methods but a better performance of the IHA-based system for pilots without any previous training about the haptic aids. DHA-based system provided instead better results after some pilot training on the experiment. Pilots reported better sensation of the wind gusts with IHA-based feedback. The two haptic aids concepts are going to be compared in an obstacle detection/avoidance task.}, file_url = {/fileadmin/user_upload/files/publications/HFR%202010_6842[0].pdf}, web_url = {http://hfr2010.wordpress.com/}, event_name = {3rd Workshop for Young Researchers on Human-Friendly Robotics (HFR 2010)}, event_place = {Tübingen, Germany}, state = {published}, author = {Alaimo SMC{alaimo}{Department Human Perception, Cognition and Action}, Pollini L{lpollini}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6655, title = {Position-Position Control with Gain-Scheduling for Telesurgical Systems}, journal = {Proceedings of the International Conference on Advanced Mechatronics (ICAM 2010)}, year = {2010}, month = {10}, pages = {283-288}, abstract = {Surgical teleoperation systems are being increasingly deployed. There are, however, remaining issues such as nonlinear characteristics of the interaction between the slave robot and soft tissues, and difficulty in employing force sensors in the surgical end-effectors of the slave. These issues make it difficult to offer a general approach to designing the overall control structure. This paper addresses these issues by proposing an optimized controller which guarantees robust stability and performance. The environment, i.e., soft tissues, is characterized with the nonlinear Hunt-Crossley model. The overall teleoperation system is modeled as a linear parameter-varying system. A gain-scheduling control scheme is adapted to design a performance-optimized controller while guaranteeing robust stability. The developed gain-scheduling control scheme shows good tracking capacity and high transparency in varied experimental conditions. Error of the transmitted impedance is significantly lower compared to other conventional control schemes for frequency band less than 2 Hz which is frequently recommended for surgical teleoperation.}, file_url = {/fileadmin/user_upload/files/publications/ICAM2010-Cho_6655[0].pdf}, web_url = {http://www-arailab.sys.es.osaka-u.ac.jp/icam2010/}, event_name = {International Conference on Advanced Mechatronics (ICAM 2010)}, event_place = {Osaka, Japan}, state = {published}, author = {Cho JH, Son HI{chakurt}{Department Human Perception, Cognition and Action}, Bhattacharjee T, Lee DG and Lee DY} } @Inproceedings{ RobuffoGiordanoFSSLB2010, title = {Towards Bilateral Teleoperation of Multi-Robot Systems}, year = {2010}, month = {10}, pages = {1-2}, abstract = {In this paper, we discuss a novel control strategy for the bilateral teleoperation of multi-robot systems, by especially focusing on the case of Unmanned aerial Vehicles (UAVs). Two control schemes are proposed: a top-down approach to maintain a desired topology of the local robots, and a bottomup approach which allows changes of topology based on local robots interactions. In both cases, passivity of overall teleoperation system is formally guaranteed. The haptic cues fed back to the operator reflect the motion status of the multirobot team and inform him about the presence of obstacles. The proposed approaches are validated through semi-experiments.}, file_url = {fileadmin/user_upload/files/publications/2011/HFR-2010-Robuffo.pdf}, web_url2 = {http://hfr2010.wordpress.com/}, event_name = {3rd Workshop for Young Researchers on Human-Friendly Robotics (HFR 2010)}, event_place = {Tübingen, Germany}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Franchi A{antonio}{Department Human Perception, Cognition and Action}, Son HI{chakurt}{Department Human Perception, Cognition and Action}, Secchi C, Lee D and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6682, title = {Virtual Storyteller in Immersive Virtual Environments Using Fairy Tales Annotated for Emotion States}, journal = {Virtual Environments 2010: Joint Virtual Reality Conference of EGVE - 16th Eurographics Symposium on Virtual Environments, EuroVR - the 7th EuroVR (INTUITION) Conference, VEC - the annual Virtual Efficiency Congress}, year = {2010}, month = {10}, pages = {65-68}, abstract = {This paper describes the implementation of an automatically generated virtual storyteller from fairy tale texts which were previously annotated for emotion. In order to gain insight into the effectiveness of our virtual storyteller we recorded face, body and voice of an amateur actor and created an actor animation video of one of the fairy tales. We also got the actor's annotation of the fairy tale text and used this to create a virtual storyteller video. With these two videos, the virtual storyteller and the actor animation, we conducted a user study to determine the effectiveness of our virtual storyteller at conveying the intended emotions of the actor. Encouragingly, participants performed best (when compared to the intended emotions of the actor) when they marked the emotions of the virtual storyteller. Interestingly, the actor himself was not able to annotate the animated actor video with high accuracy as compared to his annotated text. This argues that for future work we must have our actors also annotate their body and facial expressions, not just the text, in order to further investigate the effectiveness of our virtual storyteller. This research is a first step towards using our virtual storyteller in real-time immersive virtual environments.}, file_url = {/fileadmin/user_upload/files/publications/Alexandrova_JVRC_authors_version_6682[0].pdf}, web_url = {http://www.interaction-design.org/references/conferences/proceedings_of_the_joint_virtual_reality_conference_of_egve_-_eurovr_-_vec.html}, editor = {Kuhlen, T. , S. Coquillart, V. Interrante}, publisher = {Eurographics Association}, address = {Goslar, Germany}, booktitle = {Virtual Environments 2010}, event_name = {2010 Joint Virtual Reality Conference of EuroVR - EGVE - VEC (JVRC 2010)}, event_place = {Stuttgart, Germany}, state = {published}, ISBN = {978-3-905674-30-9}, DOI = {10.2312/EGVE/JVRC10/065-068}, author = {Alexandrova IV{ivelina}{Department Human Perception, Cognition and Action}, Volkova EP{evolk}{Department Human Perception, Cognition and Action}, Kloos U, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6771, title = {A Comparison of Direct and Indirect Haptic Aiding for Remotely Piloted Vehicles}, journal = {Proceedings of the 19th IEEE International Symposium in Robot and Human Interactive Communication (IEEE Ro-Man 2010)}, year = {2010}, month = {9}, pages = {506-512}, abstract = {The paper presents an experimental evaluation of two different Haptic aiding concepts: Direct and Indirect Haptic Aiding. Two Haptic systems were designed and tested using an experimental setup. The problem of wind gust rejection in Remotely Piloted Vehicles is used as test bench. Test results show the effectiveness of both methods but a better performance of the IHA-based system for pilots without any previous training about the experiment. DHA-based system provided instead better results after some pilot training on the experiment. Pilots reported better sensation of the wind gusts with IHA-based feedback.}, file_url = {/fileadmin/user_upload/files/publications/0174_[0].pdf}, web_url = {http://www.ieee.org/conferences_events/conferences/conferencedetails/index.html?Conf_ID=16167}, editor = {Avizzano, C. A , E. Ruffaldi, M. Fontana, M. Carrozzino, M. Bergamasco}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {19th IEEE International Symposium in Robot and Human Interactive Communication (IEEE Ro-Man 2010)}, event_place = {Viareggio, Italy}, state = {published}, DOI = {10.1109/ROMAN.2010.5598647}, author = {Alaimo SMC{alaimo}{Department Human Perception, Cognition and Action}, Pollini L{lpollini}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6632, title = {Influence of display type and field of view on drivers’ performance in a motion-based driving simulator}, journal = {Proceedings of the Driving Simulation Conference 2010 Europe (DSC Europe 2010)}, year = {2010}, month = {9}, pages = {81-88}, abstract = {Different solutions are used on driving simulators to provide visual feedback. In this study, we investigated the influence of projection technology and field of view on drivers performance in a slalom driving task. We tested a head mounted display against a curved projection system on our CyberMotion simulator, based on an anthropomorphic robot arm. The results showed that drivers performed significantly better using the projection screen than the HMD. The FoV and the motion simulation did not have a measurable influence on the performance.}, file_url = {/fileadmin/user_upload/files/publications/DSC2010_Grabe-et-al_6632[0].pdf}, web_url = {http://dsc2010.ensam.eu/}, editor = {Kemeny, A. , F. Mérienne, S. Espié}, publisher = {INRETS}, address = {Bron, France}, booktitle = {Trends in driving simulation design and experiments}, event_name = {Driving Simulation Conference Europe (DSC 2010)}, event_place = {Paris, France}, state = {published}, ISBN = {978-2-85782-685-9}, author = {Grabe V{vgrabe}{Department Human Perception, Cognition and Action}, Pretto P{pretto}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6656, title = {Towards Artificial Systems: What Can We Learn from Human Perception?}, journal = {PRICAI 2010: Trends in Artificial Intelligence}, year = {2010}, month = {9}, pages = {1-3}, abstract = {Research in learning algorithms and sensor hardware has led to rapid advances in artificial systems over the past decade. However, their performance continues to fall short of the efficiency and versatility of human behavior. In many ways, a deeper understanding of how human perceptual systems process and act upon physical sensory information can contribute to the development of better artificial systems. In the presented research, we highlight how the latest tools in computer vision, computer graphics, and virtual reality technology can be used to systematically understand the factors that determine how humans perform in realistic scenarios of complex task-solving.}, file_url = {/fileadmin/user_upload/files/publications/PRICAI-62300001%20(1)_6656[0].pdf}, web_url = {http://www.pricai2010.org/default.asp}, editor = {Zhang, B.-T. , M. A. Orgun}, publisher = {Springer}, address = {Berlin, Germany}, booktitle = {PRICAI 2010: Trends in Artificial Intelligence}, event_name = {11th Pacific Rim International Conference on Artificial Intelligence}, event_place = {Daegu, South Korea}, state = {published}, ISBN = {978-3-642-15246-7}, DOI = {10.1007/978-3-642-15246-7_1}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6715, title = {Implementation and validation of a model of the MPI Stewart platform}, journal = {Proceedings of the 2010 AIAA Modeling and Simulation Technologies Conference}, year = {2010}, month = {8}, pages = {1007-1019}, abstract = {A simulated model of the MPI Stewart platform can be used to identify the influence of motion system characteristics on human control behaviour in active closed-loop control experiments on the SIMONA Research Simulator. In this paper, a previously identified model of the MPI Stewart platform was analysed with describing function measurements, and it was found that a reduced form of the model was sufficient to capture the relevant dynamics. The reduced model was simulated on the SIMONA Research Simulator and describing function measurements were performed with two IMUs. Both IMUs revealed a resonance peak in measurements of response magnitude at the highest frequencies. A reduced time delay was found with the newer IMU. With the describing function measurements, the implementation of the MPI Stewart platform model was validated in terms of the frequency response and the time delay.}, file_url = {/fileadmin/user_upload/files/publications/Nieuwenhuizen2010_[0].pdf}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2010-8217}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference 2010}, event_place = {Toronto, Canada}, state = {published}, ISBN = {978-1-62410-152-6}, DOI = {10.2514/6.2010-8217}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, van Paassen MM, Mulder M and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ ChuangBBF2010, title = {Measuring unrestrained gaze on wall-sized displays}, year = {2010}, month = {8}, pages = {347-348}, abstract = {Motivation -- Natural gaze involves the coordinated movements of eye, head and torso. This allows access to a wide field of view, up to a range of 260° (Chen, Solinger, Poncet & Lancet, 1999). The recent increase in large displays places a demand on being able to track a mobile user's gaze over this extensive range. Research approach -- We developed an extensible system for measuring the gaze of users on wall-sized displays. Our solution combines the inputs of a conventional head-mounted eyetracker (Eyelink2©, SR Research) and motion-capture system (Vicon MX©, Vicon), to provide real-time measurements of a mobile user's gaze in 3D space. Findings/Design -- The presented system serves as a single platform for studying user behavior across a wide range of tasks: single-step saccade shifts, free-viewing of natural scenes, visual search and gaze-assisted user interfaces. Importantly, it allows eye- and head-movements to be separately measured without compromising the accuracy of combined gaze measurements. Take away message -- Unrestrained gaze movements on a large display can be accurately measured by suitably combining the inputs of conventional eye- and body-tracking hardware.}, web_url = {http://ecce2010.tudelft.nl/}, editor = {Neerincx, W. , W-P Brinkman}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {28th Annual European Conference on Cognitive Ergonomics (ECCE '10)}, event_place = {Delft, Netherlands}, state = {published}, ISBN = {978-1-60558-946-6}, DOI = {10.1145/1962300.1962379}, author = {Chuang LL{chuang}{Department Human Perception, Cognition and Action}, Bieg H-J{bieg}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Fleming RW{roland}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6428, title = {Putting Egocentric and Allocentric into Perspective}, journal = {Spatial Cognition VII: International Conference Spatial Cognition 2010}, year = {2010}, month = {8}, pages = {207-221}, abstract = {In the last decade many studies examined egocentric and allocentric spatial relations. For various tasks, navigators profit from both kinds of relations. However, their interrelation seems to be underspecified. We present four elementary representations of allocentric and egocentric relations (sensorimotor contingencies, egocentric coordinate systems, allocentric coordinate systems, and perspective-free representations) and discuss them with respect to their encoding and retrieval. Elementary representations are problematic for capturing large spaces and situations which encompass both allocentric and egocentric relations at the same time. Complex spatial representations provide a solution to this problem. They combine elementary coordinate representations either by pair-wise connections or by hierarchical embedding. We discuss complex spatial representations with respect to computational requirements and their plausibility regarding behavioral and neural findings. This work is meant to clarify concepts of egocentric and allocentric, to show their limitations, benefits and empirical plausibility and to point out new directions for future research.}, web_url = {http://www.spatial-cognition-2010.com/index.html}, editor = {Hölscher, C. , T. F. Shipley, M. Olivetti Belardinelli, J. A. Bateman, N. S. Newcombe}, publisher = {Springer}, address = {Berlin, Germany}, booktitle = {Spatial Cognition VII}, event_name = {International Conference Spatial Cognition (SC 2010)}, event_place = {Portland, OR, USA}, state = {published}, ISBN = {978-3-642-14749-4}, DOI = {10.1007/978-3-642-14749-4_19}, author = {Meilinger T{meilinger}{Department Human Perception, Cognition and Action} and Vosgerau G{vosgerau}} } @Inproceedings{ 6426, title = {The Direction Bias and the Incremental Construction of Survey Knowledge}, journal = {Cognition in Flux: Proceedings of the 32nd Annual Conference of the Cognitive Science Society}, year = {2010}, month = {8}, pages = {2500-2505}, abstract = {This study examines how spatial memory acquired from navigation is used to perform a survey task involving pointing. Participants learned a route through a virtual city by walking it multiple times in one direction on an omnidirectional treadmill. After learning, they were teleported to several locations along the route, self-localized and pointed to multiple other locations along the route. Pointing was done away from or towards the current location. Preliminary data show that participants were faster in pointing away. This suggests that pointing was based on an incremental process rather than an all-at-once process which is consistent with mentally walking through a cognitive map or constructing a mental model of currently non-visible areas of the city. On average participants pointed faster to targets located further down the route towards the end than to targets located route upwards towards the start. Analysis of individual performance showed that more participants than expected by chance showed such an effect of target direction also in their pointing accuracy. The direction of this effect differed between participants. These direction biases suggest that at least some participants encoded the environmental space by multiple interconnected locations and used this representation also for pointing.}, file_url = {/fileadmin/user_upload/files/publications/COGSCI2010-Meilinger_6426[0].pdf}, web_url = {http://cognitivesciencesociety.org/conference2010/index.html}, editor = {Ohlsson, S. , R. Catrambone}, publisher = {Cognitive Science Society}, address = {Austin, TX, USA}, event_name = {32nd Annual Conference of the Cognitive Science Society (CogSci 2010)}, event_place = {Portland, OR, USA}, state = {published}, author = {Meilinger T{meilinger}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6623, title = {Egocentric distance judgments in a large screen display immersive virtual environment}, journal = {Proceedings of the 7th Symposium on Applied Perception in Graphics and Visualization (APGV 2010)}, year = {2010}, month = {7}, pages = {57-60}, abstract = {People underestimate egocentric distances in head-mounted display virtual environments, as compared to estimates done in the real world. Our work investigates whether distances are still compressed in a large screen display immersive virtual environment, where participants are able to see their own body surrounded by the virtual environment. We conducted our experiment in both the real world using a real room and the large screen display immersive virtual environment using a 3D model of the real room. Our results showed a significant underestimation of verbal reports of egocentric distances in the large screen display immersive virtual environment, while the distance judgments of the real world were closer to veridical. Moreover, we observed a significant effect of distances in both environments. In the real world closer distances were slightly underestimated, while further distances were slightly overestimated. In contrast to the real world in the virtual environment participants overestimated closer distanc es (up to 2.5m) and underestimated distances that were further than 3m. A possible reason for this effect of distances in the virtual environment may be that participants perceived stereo cues differently when the target was projected on the floor versus on the front of the large screen.}, file_url = {/fileadmin/user_upload/files/publications/Alexandrova_APGV_authors_version_6623[0].pdf}, web_url = {http://www.apgv.org/}, editor = {Guttierez, D. , J. Kearney, M. Banks, K. Mania}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {7th Symposium on Applied Perception in Graphics and Visualization (APGV 2010)}, event_place = {Los Angeles, CA, USA}, state = {published}, ISBN = {978-1-4503-0248-7}, DOI = {10.1145/1836248.1836258}, author = {Alexandrova IV{ivelina}{Department Human Perception, Cognition and Action}, Teneva PT{pteneva}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Kloos U, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6589, title = {Horizon estimation: perceptual and computational experiments}, journal = {Proceedings of the 7th Symposium on Applied Perception in Graphics and Visualization (APGV 2010)}, year = {2010}, month = {7}, pages = {49-56}, abstract = {The human visual system is able to quickly and robustly infer a wealth of scene information -- the scene "gist" - already after 100 milliseconds of image presentation. Here, we investigated the ability to estimate the position of the horizon in briefly shown images. Being able to judge the horizon position quickly and accurately will help in inferring viewer orientation and scene structure in general and thus might be an important factor of scene gist. In the first, perceptual study, we investigated participants' horizon estimates after a 150 millisecond, masked presentation of typical outdoor scenes from different scene categories. All images were shown in upright, blurred, inverted, and cropped conditions to investigate the influence of different information types on the perceptual decision. We found that despite individual variations, horizon estimates were fairly consistent across participants and conformed well to annotated data. In addition, inversion resulted in significant differences in performance, whereas blurring did not yield any different results, highlighting the importance of global, low-frequency information for making judgments about horizon position. In the second, computational experiment, we then correlated the performance of several algorithms for horizon estimation with the human data -- algorithms ranged from simple estimations of bright-dark-transitions to more sophisticated frequency spectrum analyses motivated by previous computational modeling of scene classification results. Surprisingly, the best fits to human data were obtained with one very simple gradient method and the most complex, trained method. Overall, global frequency spectrum analysis provided the best fit to human estimates, which together with the perceptual data suggests that the human visual system might use similar mechanisms to quickly judge horizon position as part of the scene gist.}, file_url = {/fileadmin/user_upload/files/publications/apgv_final_[0].pdf}, web_url = {http://www.apgv.org/}, editor = {Guttierez, D. , J. Kearney, M. Banks, K. Mania}, publisher = {ACM}, address = {New York, NY, USA}, event_name = {7th Symposium on Applied Perception in Graphics and Visualization (APGV 2010)}, event_place = {Los Angeles, CA, USA}, state = {published}, ISBN = {978-1-4503-0248-7}, DOI = {10.1145/1836248.1836257}, author = {Herdtweck C{grueschaan}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6538, title = {Preliminary Evaluation of a Haptic Aiding Concept for Remotely Piloted Vehicles}, journal = {Haptics: Generating and Perceiving Tangible Sensations (EuroHaptics 2010)}, year = {2010}, month = {7}, pages = {418-425}, abstract = {This paper shows a preliminary experimental evaluation of a novel haptic aiding for Remotely Piloted Vehicles. The aerodynamically-inspired haptic feedback law was named Conventional Aircraft Artificial Feel, and was implemented as a variable stiffness spring. The experimental set-up comprises a fully nonlinear mathematical model of the aircraft, a visual display and a haptic device (a 3 DoF Omega Device). The tests, performed using a set of 18 naïve subjects, show the validity of the proposed approach.}, file_url = {/fileadmin/user_upload/files/publications/61920418_[0].pdf}, web_url = {http://www.eurohaptics2010.org/index.shtml}, editor = {Kappers, A.M.L. , J.B.F. Van Erp, W.M. Bergmann Tiest, F.C.T. Van Der Helm}, publisher = {Springer}, address = {Berlin, Germany}, booktitle = {Haptics: Generating and Perceiving Tangible Sensations}, event_name = {EuroHaptics 2010}, event_place = {Amsterdam, Netherlands}, state = {published}, ISBN = {978-3-642-14075-4}, DOI = {10.1007/978-3-642-14075-4_62}, author = {Alaimo SMC{alaimo}{Department Human Perception, Cognition and Action}, Pollini L{lpollini}, Magazz{\`u} A, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Innocenti M and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6541, title = {A Communication Task in HMD Virtual Environments: Speaker and Listener Movement Improves Communication}, journal = {Proceedings of the 23rd Annual Conference on Computer Animation and Social Agents (CASA 2010)}, year = {2010}, month = {6}, pages = {1-4}, abstract = {In this paper we present an experiment which investigates the influence of animated real-time self-avatars in immersive virtual environments on a communication task. Further we investigate the influence of 1st and 3rd person perspectives and the influence of tracked speaker and listener. We find that people perform best in our communication task when both the speaker and the listener have an animated self-avatar and when the speaker is in the 3rd person. The more people move the better they perform in the communication task. These results suggest that when two people in a virtual environment are animated then they do use gestures to communicate.}, file_url = {/fileadmin/user_upload/files/publications/casa_final_6541[0].pdf}, web_url = {http://casa2010.inria.fr/}, event_name = {23rd Annual Conference on Computer Animation and Social Agents (CASA 2010)}, event_place = {Saint-Malo, France}, state = {published}, author = {Dodds TJ{dodds}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6819, title = {Emotional Perception of Fairy Tales: Achieving Agreement in Emotion Annotation of Text}, journal = {Proceedings of the NAACL HLT 2010 Workshop on Computational Approaches to Analysis and Generation of Emotion in Text}, year = {2010}, month = {6}, pages = {98-106}, abstract = {Emotion analysis (EA) is a rapidly developing area in computational linguistics. An EA system can be extremely useful in fields such as information retrieval and emotion-driven computer animation. For most EA systems, the number of emotion classes is very limited and the text units the classes are assigned to are discrete and predefined. The question we address in this paper is whether the set of emotion categories can be enriched and whether the units to which the categories are assigned can be more flexibly defined. We present an experiment showing how an annotation task can be set up so that untrained participants can perform emotion analysis with high agreement even when not restricted to a predetermined annotation unit and using a rich set of emotion categories. As such it sets the stage for the development of more complex EA systems which are closer to the actual human emotional perception of text.}, file_url = {/fileadmin/user_upload/files/publications/NAACL-HLT-2010-Volkova_6819[0].pdf}, web_url = {http://www.site.uottawa.ca/~diana/naacl2010_EmotionWorkshop.html}, editor = {Inkpen, D. , C. Strapparava}, publisher = {Association for Computational Linguistics}, address = {Morristown, NJ, USA}, event_name = {NAACL HLT 2010 Workshop on Computational Approaches to Analysis and Generation of Emotion in Text}, event_place = {Los Angeles, CA, USA}, state = {published}, author = {Volkova EP{evolk}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, Meurers D, Gerdemann D and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6424, title = {Shape Centered Interest Points for Feature Grouping}, journal = {Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition Workshops (CVPRW 2010)}, year = {2010}, month = {6}, pages = {9-16}, abstract = {Image encoding using interest points is a common technique in computer vision. In this paper we present a scale and rotation invariant shape centered interest point (SCIP) detector. By means of detecting singularities in Gradient Vector Flow (GVF) fields we find points of high symmetry in the image. Due to the nature of the underlying GVF field we can employ our features to group together edge-based interest points such as SIFTs. This feature grouping provides a strong descriptor for SCIPs and can help to encode valuable information about the image for computer vision tasks. We demonstrate the main properties of our features such as scale and rotation invariance and further robustness against noise and clutter in a series of experiments. We show that the information they encode is to a certain degree complementary to SIFT. Furthermore, we evaluate them in an edge map reconstruction task to assess the amount of image information they encode. Finally, we show the power of feature grouping with our framework in a multi-category classification task on natural images from the StreetScenes database.}, file_url = {/fileadmin/user_upload/files/publications/CVPR-PCV-2010-Engel_6424[0].pdf}, web_url = {http://cvl.cse.sc.edu/pocv.html}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {CVPR 2010 Workshop on Perceptual Organization in Computer Vision (POCV 2010)}, event_place = {San Francisco, CA, USA}, state = {published}, DOI = {10.1109/CVPRW.2010.5543642}, author = {Engel D{engel}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6247, title = {A Novel Framework for Closed-Loop Robotic Motion Simulation - Part I: Inverse Kinematics Design}, journal = {Proceedings of the 2010 IEEE International Conference on Robotics and Automation (ICRA 2010)}, year = {2010}, month = {5}, pages = {3876-3883}, abstract = {This paper considers the problem of realizing a 6-DOF closed-loop motion simulator by exploiting an anthropomorphic serial manipulator as motion platform. Contrary to standard Stewart platforms, an industrial anthropomorphic manipulator offers a considerably larger motion envelope and higher dexterity that let envisage it as a viable and superior alternative. Our work is divided in two papers. In this Part I, we discuss the main challenges in adopting a serial manipulator as motion platform, and thoroughly analyze one key issue: the design of a suitable inverse kinematics scheme for online motion reproduction. Simulation results are proposed to analyze the effectiveness of our approach. Part II will address the design of a motion cueing algorithm tailored to the robot kinematics, and will provide an experimental evaluation on the chosen scenario: closed-loop simulation of a Formula 1 racing car.}, file_url = {/fileadmin/user_upload/files/publications/motsim_part_1_6247[0].pdf}, web_url = {http://icra2010.grasp.upenn.edu/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {2010 IEEE International Conference on Robotics and Automation (ICRA 2010)}, event_place = {Anchorage, AS, USA}, state = {published}, ISBN = {978-1-424-45038-1}, DOI = {10.1109/ROBOT.2010.5509647}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Masone C{masone}{Department Human Perception, Cognition and Action}, Tesch J{jtesch}{Department Human Perception, Cognition and Action}, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, Pollini L{lpollini} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6249, title = {A Novel Framework for Closed-Loop Robotic Motion Simulation - Part II: Motion Cueing Design and Experimental Validation}, journal = {Proceedings of the 2010 IEEE International Conference on Robotics and Automation (ICRA 2010)}, year = {2010}, month = {5}, pages = {3896-3903}, abstract = {This paper, divided in two Parts, considers the problem of realizing a 6-DOF closed-loop motion simulator by exploiting an anthropomorphic serial manipulator as motion platform. After having proposed a suitable inverse kinematics scheme in Part I, we address here the other key issue, i.e., devising a motion cueing algorithm tailored to the specific robot motion envelope. An extension of the well-known classical washout filter designed in cylindrical coordinates will provide an effective solution to this problem. The paper will then present a thorough experimental evaluation of the overall architecture (inverse kinematics + motion cueing) on the chosen scenario: closed-loop simulation of a Formula 1 racing car. This will prove the feasibility of our approach in fully exploiting the robot motion capabilities as a motion simulator.}, file_url = {/fileadmin/user_upload/files/publications/motsim_part_2_6249[0].pdf}, web_url = {http://icra2010.grasp.upenn.edu/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {2010 IEEE International Conference on Robotics and Automation (ICRA 2010)}, event_place = {Anchorage, AS, USA}, state = {published}, DOI = {10.1109/ROBOT.2010.5509945}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Masone C{masone}{Department Human Perception, Cognition and Action}, Tesch J{jtesch}{Department Human Perception, Cognition and Action}, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, Pollini L{lpollini} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6250, title = {Kinematic Control of Nonholonomic Mobile Manipulators in the Presence of Steering Wheels}, journal = {Proceedings of the 2010 IEEE International Conference on Robotics and Automation (ICRA 2010)}, year = {2010}, month = {5}, pages = {1792-1798}, abstract = {We consider the kinematic control problem for nonholonomic mobile manipulators (NMMs) whose base contains steering wheels. For all typical tasks, the steering velocity inputs of such systems do not appear in the differential relationship between the first-order time derivative of the task output and the available NMM inputs. As a consequence, these inputs are not used by velocity-level kinematic control laws based on simple (pseudo)inversion of the task Jacobian, leading in general to the impossibility of completing the task. We propose two control solutions to this open problem based on the framework of input-output feedback linearization. First, a static feedback law is presented that defines the unspecified steering velocities via an optimization action in the null space of the task Jacobian. A dynamic feedback law is then proposed based on the input-output differential map obtained by considering the task acceleration. In this case, the velocity of the steering wheels becomes an active input for task exec ution, together with the manipulator joint accelerations and the driving accelerations of the base. The feasibility and performance of the two kinematic controllers are compared in simulation for a car-like base carrying a planar manipulator.}, file_url = {/fileadmin/user_upload/files/publications/KinSteer_6250[0].pdf}, web_url = {http://icra2010.grasp.upenn.edu/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {2010 IEEE International Conference on Robotics and Automation (ICRA 2010)}, event_place = {Anchorage, AS, USA}, state = {published}, ISBN = {978-1-424-45038-1}, DOI = {10.1109/ROBOT.2010.5509570}, author = {De Luca A, Oriolo G and Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6460, title = {Psychophysical Evaluation of Control Scheme Designed for Optimal Kinesthetic Perception in Scaled Teleoperation}, journal = {Proceedings of the IEEE International Conference on Robotics and Automation (ICRA 2010)}, year = {2010}, month = {5}, pages = {5346-5351}, abstract = {This paper focuses on psychophysical evaluation of the control scheme developed to optimize the kinesthetic perception during the scaled teleoperation. The control problem is formulated as a multi-objective constrained optimization. The objective function is a metric which quantifies the detection and discrimination capacity of the human operator. The constraints are position tracking accuracy and absolute stability of the scaled teleoperation. Two popular control architectures, i.e., the position-position and the force-position control architectures are considered in this paper. The method of limits is employed in this paper to conduct the psychophysical experiments and evaluation. Results show that the developed control scheme is more effective in increasing the detection and discrimination capacity of human subjects as compared to the traditional transparency-optimized control laws.}, web_url = {http://icra2010.grasp.upenn.edu/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {2010 IEEE International Conference on Robotics and Automation (ICRA 2010)}, event_place = {Anchorage, AK, USA}, state = {published}, ISBN = {978-1-424-45038-1}, DOI = {10.1109/ROBOT.2010.5509368}, author = {Son HI{chakurt}{Department Human Perception, Cognition and Action}, Bhattacharjee T, Jung HR and Lee DY} } @Inproceedings{ PastraWSVK2010, title = {The POETICON Corpus: Capturing Language Use and Sensorimotor Experience in Everyday Interaction}, year = {2010}, month = {5}, pages = {3031-3036}, abstract = {Natural language use, acquisition, and understanding takes place usually in multisensory and multimedia communication environments. Therefore, for one to model language in its interaction and integration with sensorimotor experiences, one needs a representative corpus of such interplay. In this paper, we will present the first corpus of language use and sensorimotor experience recordings in everyday human:human interaction, in which spontaneous language communication has been recorded along with corresponding multiview video recordings, recordings of 3D full body kinematics, and 3D tracking of objects in focus. It is a twelve-hour corpus which comprises of six everyday human:human interaction scenes, each one performed 3 times by 4 different English-speaking couples (interaction between a male and a female actor), each couple acting each scene in two settings: a fully naturalistic setting in which 5-camera multi-view video recordings take place, and a high-tech setting, with full body motion capture for both individuals, a 2-camera multiview video recording, and 3D tracking of focus objects. The corpus has been developed within an EU-funded cognitive systems research project, POETICON (http://www.poeticon.eu), and represents a new type of language resources for cognitive systems. Namely, a corpus that reveals the dynamic role of language in its interplay with sensorimotor experiences and which allows one to computationally model this interplay.}, file_url = {fileadmin/user_upload/files/publications/LREC-2010-Pastra.pdf}, web_url = {http://www.lrec-conf.org/lrec2010/}, editor = {Calzolari , N. , K. Choukri, B. Maegaard, J. Mariani, J. Odijk, S. Piperidis, M. Rosner, D. Tapias}, publisher = {ELRA}, address = {Paris, France}, event_name = {Seventh International Conference on Language Resources and Evaluation (LREC 2010)}, event_place = {Valletta, Malta}, state = {published}, ISBN = {2-9517408-6-7}, author = {Pastra K, Wallraven C{walli}{Department Human Perception, Cognition and Action}, Schultze M{mschultze}{Department Human Perception, Cognition and Action}, Vatakis A and Kaulard K{kascot}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6396, title = {Visual-Vestibular Feedback for Enhanced Situational Awareness in Teleoperation of UAVs}, journal = {Proceedings of the American Helicopter Society 66th Annual Forum and Technology Display}, year = {2010}, month = {5}, pages = {2809-2818}, abstract = {This paper presents a novel concept for improving the situational awareness of a ground operator in remote control of a Unmanned Arial Vehicle (UAV). To this end, we propose to integrate vestibular feedback with the usual visual feedback obtained from a UAV onboard camera. We use our motion platform, the CyberMotion simulator, so as to reproduce online the desired motion cues. We test this architecture by flying a small-scale quadcopter and run a detailed performance evaluation on 12 test subjects. We then discuss the results in terms of possible benefits for facilitating the remote control task.}, file_url = {/fileadmin/user_upload/files/publications/AHS_FORUM66_[0].pdf}, web_url = {http://www.vtol.org/forum66/forum66.html}, publisher = {AHS International}, address = {Alexandria, VA, USA}, booktitle = {AHS International 66th Annual Forum}, event_name = {66th American Helicopter Society International Annual Forum 2010}, event_place = {Phoenix, AZ, USA}, state = {published}, ISBN = {978-1-61782-926-0}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Deusch H{deusch}{Department Human Perception, Cognition and Action}, L\"achele J{siddian}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6292, title = {Perceptual representations of parametrically-defined and natural objects comparing vision and haptics}, journal = {Proceedings of the Haptics Symposium 2010}, year = {2010}, month = {4}, pages = {35-42}, abstract = {Studies concerning how the brain might represent objects by means of a perceptual space have primarily focused on the visual domain. Here we want to show that the haptic modality can equally well recover the underlying structure of a physical object space, forming a perceptual space that is highly congruent to the visual perceptual space. By varying three shape parameters a physical shape space of shell-like objects was generated. Sighted participants explored pictures of the objects while blindfolded participants haptically explored 3D printouts of the objects. Similarity ratings were performed and analyzed using multidimensional scaling (MDS) techniques. Visual and haptic similarity ratings highly correlated and resulted in very similar visual and haptic MDS maps. To investigate to which degree these results are transferrable to natural objects, we performed the same visual and haptic similarity ratings and multidimensional scaling analyses using a set of natural sea shells. Again, we found very similar per ceptual spaces in the haptic and visual domain. Our results suggest that the haptic modality is capable of surprisingly acute processing of complex shape.}, file_url = {/fileadmin/user_upload/files/publications/Haptics2010-Gaissert_6292[0].pdf}, web_url = {http://www.hapticssymposium.org/next_conference.html}, editor = {Colgate, J. E., S. Lederman, D. Prattichizzo}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE Haptics Symposium 2010}, event_place = {Waltham, MA, USA}, state = {published}, ISBN = {978-1-424-46821-8}, DOI = {10.1109/HAPTIC.2010.5444683}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6246, title = {Eye and Pointer Coordination in Search and Selection Tasks}, journal = {Proceedings of the Symposium on Eye Tracking Research and Applications (ETRA 2010)}, year = {2010}, month = {3}, pages = {89-92}, abstract = {Selecting a graphical item by pointing with a computer mouse is a ubiquitous task in many graphical user interfaces. Several techniques have been suggested to facilitate this task, for instance, by reducing the required movement distance. Here we measure the natural coordination of eye and mouse pointer control across several search and selection tasks. We find that users automatically minimize the distance to likely targets in an intelligent, task dependent way. When target location is highly predictable, top-down knowledge can enable users to initiate pointer movements prior to target fixation. These findings ques-tion the utility of existing assistive pointing techniques and suggest that alternative approaches might be more effective.}, file_url = {/fileadmin/user_upload/files/publications/ETRA2010-Bieg_6246[0].pdf}, web_url = {http://etra.cs.uta.fi/}, editor = {Morimoto, C. H., H. Istance, A. Hyrskykari, Q. Ji}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {Symposium on Eye Tracking Research and Applications (ETRA 2010)}, event_place = {Austin, TX, USA}, state = {published}, DOI = {10.1145/1743666.1743688}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}, Chuang LL{chuang}{Department Human Perception, Cognition and Action}, Fleming RW{roland}{Department Human Perception, Cognition and Action}, Reiterer H and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6293, title = {Visual and Haptic Perceptual Spaces From Parametrically-Defined to Natural Objects}, journal = {Cognitive shape processing: papers from the AAAI Spring Symposium}, year = {2010}, month = {3}, pages = {2-7}, abstract = {In this study we show that humans form very similar perceptual spaces when they explore parametrically-defined shell-shaped objects visually or haptically. A physical object space was generated by varying three shape parameters. Sighted participants explored pictures of these objects while blindfolded participants haptically explored 3D printouts of the objects. Similarity ratings were performed and analyzed using multidimensional scaling (MDS) techniques. Visual and haptic similarity ratings highly correlate and resulted in very similar visual and haptic MDS maps providing evidence for one shared perceptual space underlying both modalities. To investigate to which degree these results are transferrable to natural objects, we performed the same visual and haptic similarity ratings and multidimensional scaling analyses using a set of natural sea shells.}, file_url = {/fileadmin/user_upload/files/publications/AAAI-2010-Gaissert_6293[0].pdf}, web_url = {http://www.spatial-cognition.de/CSP/}, editor = {Barkowsky, T. , S. Bertel, C. Hölscher, T. F. Shipley}, publisher = {AAAI Press}, address = {Menlo Park, CA, USA}, event_name = {AAAI 2010 Spring Symposium on Cognitive Shape Processing}, event_place = {Stanford, CA, USA}, state = {published}, author = {Gaissert N{ninagaissert}{Department Human Perception, Cognition and Action}, Ulrichs K{ulrichs}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Inbook{ 5961, title = {Markerless tracking of dynamic 3D scans of faces}, year = {2010}, month = {12}, pages = {255-276}, web_url = {http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=12290}, editor = {Curio, C. , H. H. Bülthoff, M. A. Giese}, publisher = {MIT Press}, address = {Cambridge, MA, USA}, booktitle = {Dynamic Faces: Insights from Experiments and Computation}, state = {published}, ISBN = {978-0-262-01453-3}, author = {Walder C{walder}{Department Empirical Inference}{Department Human Perception, Cognition and Action}, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Sch\"olkopf B{bs}{Department Empirical Inference} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inbook{ 5960, title = {Recognition of Dynamic Facial Action Probed by Visual Adaptation}, year = {2010}, month = {12}, pages = {47-65}, web_url = {http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=12290}, editor = {Curio, C. , H. H. Bülthoff, M. A. Giese}, publisher = {MIT Press}, address = {Cambridge, MA, USA}, booktitle = {Dynamic Faces: Insights from Experiments and Computation}, state = {published}, ISBN = {978-0-262-01453-3}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}, Giese MA{giese}, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inbook{ 4491, title = {Motor Involvement in Action and Object Perception: Similarity and Complementarity}, year = {2010}, month = {11}, pages = {27-52}, web_url = {http://www.psypress.com/grounding-sociality-9781848728998}, editor = {Semin, G. R. , G. Echterhoff}, publisher = {Psychology Press}, address = {New York, NY, USA}, booktitle = {Grounding sociality: neurons, mind, and culture}, state = {published}, ISBN = {978-1-84872-899-8}, author = {Graf M{grafm}{Department Human Perception, Cognition and Action}, Sch\"utz-Bosbach S and Prinz W} } @Inbook{ 4492, title = {Categorization and Object Shape}, year = {2010}, pages = {73-101}, abstract = {Categorization is essential for perception and provides an important foundation for higher cognitive functions. In this review, I focus on perceptual aspects of categorization, especially related to object shape. In order to visually categorize an object, the visual system has to solve two basic problems. The first one is how to recognize objects after spatial transformations like rotations and size-scalings. The second problem is how to categorize objects with different shapes as members of the same category. I review the literature related to these two problems against the background of the hierarchy of transformation groups specified in Felix Klein’s Erlanger Programm. The Erlanger Programm provides a general framework for the understanding of object shape, and may allow integrating object recognition and categorization literatures.}, web_url = {http://www.springerlink.com/content/m543xj3618683ml0/}, editor = {Glatzeder, B. M. , V. Goel, A. Müller}, publisher = {Springer}, address = {Berlin, Germany}, series = {Parmenides book series on thinking}, booktitle = {Towards a theory of thinking: building blocks for a conceptual framework}, state = {published}, ISBN = {978-3-642-03129-8}, DOI = {10.1007/978-3-642-03129-8_6}, author = {Graf M{grafm}{Department Human Perception, Cognition and Action}} } @Techreport{ BeykirchSB2010, title = {Evaluation of the baseline perception models and required amendments}, year = {2010}, number = {SUPRA D4.1}, state = {published}, author = {Beykirch M{kab}{Department Human Perception, Cognition and Action}, Soyka F{fsoyka}{Department Human Perception, Cognition and Action} and Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}} } @Poster{ 7068, title = {"Own-species" bias in the categorical representation of a human/monkey continuum in the human and non-human primate temporal lobe}, year = {2010}, month = {11}, volume = {40}, number = {581.20}, abstract = {While face categorization is a fundamental cognitive ability of human and non-human primates, its neural basis remain poorly understood. Using a new morphing technique, we created realistic three-dimensional morphed faces that linearly span the continuum between humans and monkeys (“species” continuum). Extensive categorization and discrimination experiments in human observers show that humans perceive the “species” continuum categorically. Moreover, the position of the categorical boundary is shifted from the center towards the human end of the continuum, suggesting a higher sensitivity to changes near the own-species prototype. We presented a subset of these faces to human subjects in a block-design fMRI experiment to record BOLD signals from the temporal lobe while participants performed an unrelated task at fixation. We applied a multivariate approach based on (Pearson) correlations to compute the difference between activity patterns elicited by faces along the continuum. Using this method, we looked for a categorical representation in face selective areas previously defined using an independent, standard "Face-localizer" experiment. Consistent with the psychophysical results, we found a categorical response with a bias towards the human end of the stimulus continuum in the activation patterns of the left human STS. In addition, activation in human ventral temporal cortex was most sensitive to deviations from the human prototype. To look for similar effects in monkeys, we applied an equivalent multivariate approach to analyze extracellular signals from a population of neurons recorded from the STS of two macaque monkeys while they fixated at the same type of faces. Additionally, the position of the perceptual category boundary was determined with a preferential-looking-time experiment. In both behavioral and neuronal monkey data, we found a categorical representation of the continuum, but in this case, with a bias towards the monkey end of the continuum. Our results demonstrate the neural basis of categorical representation of a facial attribute in the human and non-human primate brain. Together, our findings suggest that experience can lead to significant shifts in category boundary for face stimuli.}, web_url = {http://www.sfn.org/am2010/index.aspx?pagename=abstracts_main}, event_name = {40th Annual Meeting of the Society for Neuroscience (Neuroscience 2010)}, event_place = {San Diego, CA, USA}, state = {published}, author = {Sigala Alanis GR{sigala}{Department Physiology of Cognitive Processes}, Schultz J{johannes}{Department Human Perception, Cognition and Action}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes} and Rainer G{gregor}} } @Poster{ 7056, title = {Evidence for predictive coding in early visual cortex in context of self-induced visual motion}, year = {2010}, month = {11}, volume = {40}, number = {74.11}, abstract = {The model of “predictive coding” suggests that feedback from a higher- to a lower-order visual area carries predictions of lower-level neural activities, whereas the feedforward connections carry the residual errors between the predictions and the actual lower-level activities (Rao and Ballard, 1999). We tested this theory in context of processing of planar motion in early (foveal) visual cortex. In a 2x2 factorial design, human subjects either fixated (eyes still) or carried out smooth pursuit on a display containing a planar random dot-field that was either stationary or moving coherently in-plane. This led to four conditions: (a) fixation on static dot-field, (b) fixation on moving dot-field, (c) pursuit on static dot-field, (d) pursuit of moving dot-field (pursuit was locked to the dot-motion). Neural activity was measured using fMRI at 3T. If early visual cortex coded for retinal motion, (b) and (c) would be expected to activate early visual cortex equally, and more than (a) and (d). In contrast, predictive coding would result in different responses. In addition to the above, early visual cortex would also code the error signal for mismatches between retinal motion input and the prediction for retinal motion, based on e.g. pursuit-related efferent copies. Such mismatches between prediction and input would occur in (b) (retinal motion without prediction of it) and in (d) (absence of retinal motion despite prediction of it). Note that these mismatches are equivalent to the presence of objective motion in the display. Thus, predictive coding would lead to highest responses in (b) (error + input), medium responses in (c) (input only) and (d) (error only), and lowest response in (a). We found (across the whole brain) the only activity satisfying these criteria in the occipital poles. The occipital poles contain the foveal confluence of early visual areas V1-V3, and are thus the key candidate for the above hypothesis. Their responses matched the hypothesized pattern precisely. In contrast, activity in motion responsive areas such as V5/MT+ and parietal regions was mainly driven by eye-movements and by retinal motion. Offline eye-tracking revealed that our results cannot be explained by differential fixation accuracies across conditions. It remains to be elucidated whether predictive coding actually accounts for the results, or whether direct feedback of objective motion signals from higher-level areas sums up with retinal input to the response observed in the occipital pole. Nevertheless, our results let us conclude that activity in the foveal representation of the early visual cortex fully match the predictions of Rao and Ballard (1999) for predictive coding.}, web_url = {http://www.sfn.org/am2010/index.aspx?pagename=abstracts_main}, event_name = {40th Annual Meeting of the Society for Neuroscience (Neuroscience 2010)}, event_place = {San Diego, CA, USA}, state = {published}, author = {Fischer E{efischer}{Department Physiology of Cognitive Processes}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes} and Bartels A{abartels}{Department Physiology of Cognitive Processes}} } @Poster{ SchultzBP2011_2, title = {What human brain regions like about moving faces}, year = {2010}, month = {11}, volume = {40}, number = {393.10}, abstract = {Visual perception of moving faces activates parts of the human superior temporal sulcus (STS) whereas static facial information is mainly processed in areas of ventral temporal and lateral occipital cortex. However, recent findings show that the latter regions also respond more to moving faces than to static faces (Schultz and Pilz, 2009). This study investigated the origin of this activation increase. We considered the following causes: (1) facial motion per se (2) increased static information due to the higher number of frames constituting the movie stimuli, and/or (3) increased attention towards moving faces, which would increase the response in face-sensitive areas through top-down modulation. We presented non-rigidly moving faces to participants lying in an fMRI scanner. We manipulated static face information and fluidity of the motion in the stimuli by presenting ordered and scrambled sequences of frames at temporal resolutions of 25 frames per second (fps) which were perceived as fluid motion when ordered, but as very non-fluid when scrambled, 12.5 fps (still perceived as fluid when ordered) and 5 fps (significantly less fluid when ordered, with smallest effect of scrambling). To control the influence of attention, subjects were asked to perform a target detection task that was unrelated to the face stimuli (one-back matching task on a stream of letters presented at fixation). Results confirm the increased activation induced by facial motion in the face-sensitive fusiform and superior temporal regions. A purely attention-based effect can be ruled out given that the task performance was far from ceiling performance and equal across conditions. While activation generally increased with the number of frames, a significant reduction of activation was observed due to frame-scrambling the stimuli. These results indicate that the activation increase induced by moving faces is due to the motion of the stimulus (i.e. temporal order of the frames) and not only to increased static information or attentional modulation.}, web_url = {http://www.sfn.org/am2010/index.aspx?pagename=final_program}, event_name = {40th Annual Meeting of the Society for Neuroscience (Neuroscience 2010)}, event_place = {San Diego, CA, USA}, state = {published}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action}, Brockhaus M{mabrockhaus}{Department Human Perception, Cognition and Action} and Pilz K{kpilz}{Department Human Perception, Cognition and Action}} } @Poster{ 7086, title = {Learning and Recognizing 3D Objects by Combination of Visual and Proprioceptive Information}, year = {2010}, month = {10}, volume = {11}, number = {9}, pages = {29}, abstract = {One major difficulty in computational object recognition lies in the fact that a 3D object can be seen from an infinite number of viewpoints. Thus, the issue arises that objects with different 3D shapes often share similar 2D views. Humans are able to resolve this kind of ambiguity by producing additional views through object manipulation or self movement. In both cases the action made provides proprioceptive information linking the visual information retrieved from the obtained views. Following this process, we combine visual and proprioceptive information to increase recognition performance of a computer vision system. In our approach we place a 3D model of an unknown object in the hand of a simulated anthropomorphic robot arm. The robot now executes a predefined exploratory movement to acquire a variety of different object views. To assure computational tractability, a subset of representative views is selected using the Keyframe concept by Wallraven et al. (2007). Each remaining frame is then annotated with the respective proprioceptive configuration of the robot arm and the transitions between these configurations are treated as links between object views. For recognizing objects this representation can be used to control the robot arm based on learned data. If both proprioceptive and visual data agree on a candidate, the object was recognized successfully. We investigated recognition performance using this method. The results show that the number of misclassified results decreases significantly as both sources â visual and proprioceptive â are available, thus demonstrating the importance of a combined space of visual and proprioceptive information.}, web_url = {http://www.neuroschool-tuebingen-nena.de/fileadmin/user_upload/Dokumente/neuroscience/AbstractbookNeNa2010u.pdf}, event_name = {11th Conference of Junior Neuroscientists of Tübingen (NeNa 2010)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Browatzki B{browatbn}{Department Human Perception, Cognition and Action}} } @Poster{ 7090, title = {Proteins: Single particle reconstruction based on 2d crystals}, year = {2010}, month = {10}, volume = {11}, number = {13}, pages = {33}, abstract = {Structural biology is a new branch of basic research and avails oneself of knowledge from many other sciences like molecular biology, chemistry, biophysics and computer science. The goal of structural biology is a better understanding of biological processes at atomic resolution. To reconstruct proteins three different techniques do exist: X-ray crystallography, PNRM and single particle refinement. At the Karolinska Institute we developed a new method basing on single particle refinement combined with the knowledge we gain from the symmetric order of a crystal. Therefore we developed and implemented two new process steps for the well known reconstruction software EMAN2. The first process step improves the boxing tool - the cutting of single protein unit cells from the TEM image. The second step improves the refinement by decreasing the number of possible Eularian angles. To proof our results we tested the new software package on the sugar symporter MelB. The best resolution of MelB gained by single particle is 8Å [Purhonen: Three-dimensional structure of the suger syporter. Journal of Structural Biology, 152:76-83, 2005]. Based on the first experiments and testings it seems that a resolution better than 6Å can be achieved with the same number of iterations and the same image set as used in the 8Å-refinement. The refinement process according to the less number of alignments is much faster now. About 40% of less time is necessary.}, web_url = {http://www.neuroschool-tuebingen-nena.de/fileadmin/user_upload/Dokumente/neuroscience/AbstractbookNeNa2010u.pdf}, event_name = {11th Conference of Junior Neuroscientists of Tübingen (NeNa 2010)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Ryll M{maryll}{Department Human Perception, Cognition and Action}} } @Poster{ 6798, title = {Towards Building a 4D Morphable Face Model}, year = {2010}, month = {10}, pages = {11}, abstract = {Morphable models have proven to be very successful for analyzing and synthesizing 2D and 3D recordings of faces. They are used extensively in computer vision, computer graphics as well as in psychology research. The growing interest in extending this work from static to dynamic faces [Curio et al. 2010] has led us to build a large database of three-dimensional facial deformation data. In comparison to other databases, this database contains a large corpus of facial deformations that were carefully put into dense correspondence. From that we can obtain generative facial expression models to build a "4D Morphable Face Model", extending previous work for identity [Blanz and Vetter 1999].}, web_url = {http://www.cstr.ed.ac.uk/faa/}, event_name = {ACM/SSPNET 2nd International Symposium on Facial Analysis and Animation (FAA 2010)}, event_place = {Edinburgh, UK}, state = {published}, DOI = {10.1145/1924035.1924038}, author = {Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Poster{ 6755, title = {Velocity-dependent curvature gain and avatar use for Redirected Walking}, year = {2010}, month = {10}, pages = {1-2}, abstract = {We investigated in a study whether humans’ sensitivity to curved walking is affected by their walking velocity. Amongst other techniques, redirecting users of an immersive virtual environment on a curved path is part of the so-called ’Redirected Walking’. We conducted an experiment in which 12 participants walked specific curvatures at given speeds in a VR. We found that people are significantly less sensitive to walking on a curve when walking slower. Moreover, we assume the possibility of using avatars to support redirection algorithms as it was shown by Llobera et al. ([LSRS10]) that proxemics holds true for avatars in virtual environments, too. In this work, we depict three possible applications of how avatars could be used to achieve a better redirection.}, file_url = {/fileadmin/user_upload/files/publications/JVRC_Manuscript_[0].pdf}, web_url = {http://www.interaction-design.org/references/conferences/proceedings_of_the_joint_virtual_reality_conference_of_egve_-_eurovr_-_vec.html}, editor = {Kuhlen, T. , S. Coquillart, V. Interrante}, publisher = {Eurographics Association}, address = {Goslar, Germany}, booktitle = {Virtual Environments 2010}, event_name = {2010 Joint Virtual Reality Conference of EuroVR - EGVE - VEC (JVRC 2010)}, event_place = {Stuttgart, Germany}, state = {published}, ISBN = {978-3-905674-30-9}, author = {Neth CT{neth}{Department Human Perception, Cognition and Action}, Souman JL{souman}{Department Human Perception, Cognition and Action}, Engel D{engel}{Department Human Perception, Cognition and Action}, Kloos U, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ 7088, title = {Virtual Storytelling of Fairy Tales: Towards Simulation of Emotional Perception of Text}, year = {2010}, month = {10}, volume = {11}, number = {11}, pages = {31}, abstract = {Emotion analysis (EA) is a rapidly developing area in computational linguistics. For most EA systems, the number of emotion classes is very limited and the text units the classes are assigned to are discrete and predefined. The question we address is whether the set of emotion categories can be enriched and whether the units to which the categories are assigned can be more flexibly defined. Six untrained participants annotated a corpus of eight texts having no predetermined annotation units and using fifteen emotional categories. The inter-annotator agreement rates were considerably high for this difficult task: 0.55 (moderate) on average, reaching 0.82 (almost perfect) with some annotator pairs. The final application of the intended EA system is predominantly in the emotion enhancement of human-computer interaction in virtual reality. The system is meant to be a bridge between unprocessed input text and visual and auditory information, like generated speech, facial expressions and body language. The first steps towards integrating text-based information annotated for emotion categories and simulation of human emotional perception of texts in story telling scenarios for virtual reality are already made. We have created a virtual character, whose animation of face and body is driven by annotations in text.}, web_url = {http://www.neuroschool-tuebingen-nena.de/fileadmin/user_upload/Dokumente/neuroscience/AbstractbookNeNa2010u.pdf}, event_name = {11th Conference of Junior Neuroscientists of Tübingen (NeNa 2010)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Volkova E{evolk}{Department Human Perception, Cognition and Action}} } @Poster{ 7089, title = {Visual stimulus timing precision in Psychtoolbox-3: Tests, pitfalls & solutions}, year = {2010}, month = {10}, volume = {11}, number = {12}, pages = {32}, abstract = {Visual stimulation paradigms in perception research often require accurate timing for presentation of visual stimuli. Acquisition of exact stimulus update timestamps in realtime is often crucial, both for synchronization of stimulus updates between different presentation modalities and for logging. Modern graphics hardware, multi-core processors and operating systems provide a far higher level of functionality, flexibility, and performance in terms of throughput, than systems a decade ago. They also pose new challenges for precise presentation timing or timestamping. Typical causes of interference are, eg the dynamic power management of modern graphics cards and computers, novel hybrid graphics solutions, user interface desktop composition and the properties of graphics- and CPU-scheduling of the latest generation of operating systems. This work presents results for the accuracy and robustness of visual presentation timing and timestamping tests, conducted within Psychtoolbox-3 (Kleiner et al, 2007 Perception 36 ECVP Supplement, 14) on different operating systems and graphics cards under realistic stimulus presentation loads. It explains some of the common pitfalls one can encounter when trying to achieve exact timing and some methods to avoid timing problems or reduce their severeness.}, web_url = {http://www.neuroschool-tuebingen-nena.de/fileadmin/user_upload/Dokumente/neuroscience/AbstractbookNeNa2010u.pdf}, event_name = {11th Conference of Junior Neuroscientists of Tübingen (NeNa 2010)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}} } @Poster{ WallravenSMVAVP2010, title = {Understanding Objects and Actions: a VR Experiment}, year = {2010}, month = {9}, pages = {1-2}, abstract = {The human capability to interpret actions and to recognize objects is still far ahead of that of any technical system. Thus, a deeper understanding of how humans are able to interpret human (inter)actions lies at the core of building better artificial cognitive systems. Here, we present results from a first series of perceptual experiments that show how humans are able to infer scenario classes, as well as individual actions and objects from computer animations of everyday situations. The animations were created from a unique corpus of real-life recordings made in the European project POETICON using motion-capture technology and advanced VR programming that allowed for full control over all aspects of the finally rendered data.}, file_url = {fileadmin/user_upload/files/publications/2011/JVRC-2010-Wallraven.pdf}, web_url = {http://www.interaction-design.org/references/conferences/proceedings_of_the_joint_virtual_reality_conference_of_egve_-_eurovr_-_vec.html}, event_name = {2010 Joint Virtual Reality Conference of EuroVR - EGVE - VEC (JVRC 2010)}, event_place = {Stuttgart, Germany}, state = {published}, author = {Wallraven C{walli}{Department Human Perception, Cognition and Action}, Schultze M{mschultze}{Department Human Perception, Cognition and Action}, Mohler B{mohler}{Department Human Perception, Cognition and Action}, Volkova E{evolk}{Department Human Perception, Cognition and Action}, Alexandrova I{ivelina}{Department Human Perception, Cognition and Action}, Vatakis A{vatakis} and Pastra K} } @Poster{ 6404, title = {"Where is the sun?": The sun is "up" in the eye of the beholder}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {146}, abstract = {In environments where orientation is ambiguous, the visual system uses prior knowledge about lighting coming from above to recognize objects, reorient the body, and determine which way is up (where is the sun?). It has been shown that when observers are tilted to the side relative to gravity, the orientation of the light-from-above prior will change in a direction between the orientation of the body, gravity and the visual surround. The contribution of ocular torsion in this change of the light-from-above prior has been acknowledged but not specifically addressed. Here we test the hypothesis that when lighting direction is the only available visual orientation cue, change in orientation of the light-from-above prior is accounted for by ocular torsion. Observers made convex-concave judgments of a central shaded disk, flanked by three similarly- and three oppositely-shaded disks. Lighting was tested every 15° in roll in the fronto-parallel plane. Observers were tested when upright, supine, and tilted every 30 ° in role relative to gravity. Our results show that change of the light-from-above prior is well predicted from a sum of two sines; one consistent with predicted ocular torsion, the other consistent with an additional component varying with twice the frequency of body tilt.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100409}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Ernst MO{marc}{Research Group Multisensory Perception and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6606, title = {Does adding a visual task component affect fixation accuracy?}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {35}, abstract = {Video-based eye-trackers are typically calibrated by instructing participants to fixate a series of dots, the physical locations of which are known to the system. Unfortunately, this procedure does not verify if fixation has actually occurred at the desired locations. This limitation can be remedied by requiring participants to perform a simple visual discrimination task at each location, thus mandating accurate fixation. Still, it remains an open question whether this modification could affect fixation accuracy. In the current study, we compared the accuracy of fixations that were performed with a visual discrimination task and those without such a requirement. Participants either identified the orientation of a small Landolt C (size = 0.1°) or fixated a similar probe without performing the task. Results indicate that participants fixated equally well in both tasks (mean diff. of abs. error = 0.01°, Bayes factor B01 = 4.0 with JZS prior, see [Rouder et al., 2009, Psychonomic Bulletin &am p;am p;am p; R eview, 16(2), 225-237]). Given this, we propose the implementation of this visual discrimination task to eye-tracking calibration protocols as it elicits verifiable fixations without compromising fixation accuracy.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100606}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}, Chuang LL{chuang}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6624, title = {Egocentric distance judgments in a large-screen immersive display virtual environment}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {51}, abstract = {People underestimate egocentric distances in head-mounted display virtual environments (VEs) as compared to the real world. In a recent study [Riecke et al, 2009, APGV, 15-18] it was shown that when a person viewed a photorealistic world through an HMD or a large screen display (while sitting and not moving their head) they did not underestimate egocentric distances. We further investigate whether people underestimate egocentric distances in a large screen immersive display. In our experiment, participants were asked to report verbal estimates of egocentric distances in a large screen display with floor projection or in the real world. Overall, in the virtual world we found an underestimation of distances by 17% as compared to near accurate performance in the real world. Moreover, in the virtual world there was an effect of distance, which indicated overestimation for distances that occurred before the screen (3.5 meters), while for distances past the physical screen there was underestimation. To determine th e full reason for these effects further analysis is needed. Our results demonstrate that egocentric distance judgments are also underestimated in a large screen immersive display as compared to the real world.}, file_url = {/fileadmin/user_upload/files/publications/Alexandrova_JVRC_authors_version_6624[0].pdf}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100136}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Alexandrova IV{ivelina}{Department Human Perception, Cognition and Action}, Teneva PT{pteneva}{Department Human Perception, Cognition and Action}, Kloos U, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ FischerBLB2010, title = {Functional characteristics of a motion responsive region in the posterior cingulate cortex compared to V5/MT and MST}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {95}, abstract = {Motion processing regions apart from V5+/MT+ are still relatively poorly understood. The cingulate sulcus visual area (CSv) in the dorsal posterior cingulate cortex (dPCC) was previously described to respond preferentially to coherent motion and implied in ego-motion processing. We used fMRI to compare responses of CSv/dPCC and of areas V5/MT and MST to distinct types of motion and self-motion cues such as retinal motion and objective motion, determined during pursuit. Both V5/MT and MST had a strong preference for contra- versus ipsi-lateral stimulation, no preference for 2D planar motion versus 3D flow, and reduced yet significant responses to random motion. In contrast, CSv/dPCC preferred 2D planar motion over 3D flow, showed no lateralization, and did not respond to random motion. All areas responded strongly to eye-movement related signals, however CSv responded more to ‘real’ motion than to retinal motion while the reverse was the case for V5/MT and MST. CSv/dPCC thus differs from other motion-responsive regions by its unique preference to full-field, coherent and planar motion cues and its enhanced capability to respond to real motion. These results place CSv/dPCC in a good position to process visual and non-visual cues related to self-induced motion, especially those associated to eye-movements.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100307}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Fischer E{efischer}{Department Physiology of Cognitive Processes}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes} and Bartels A{abartels}{Department Physiology of Cognitive Processes}} } @Poster{ 6776, title = {Horizon estimation: Perceptual and computational experiments}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {106}, abstract = {The human visual system is able to extract a vast amount of scene information from a briefly shown picture. Here, we investigated the ability to accurately and quickly estimate horizon position, which is related to viewer orientation and scene structure in general. In the first, perceptual study, we asked 18 participants to estimate the horizon position after a 150 ms, masked presentation of typical outdoor scenes from different scene categories. All images were shown in upright, blurred, inverted, and cropped conditions to investigate the influence of different information types on the perceptual decision. Overall, participants were fairly consistent in their estimates (r=0.62); inverted images, however, produced significantly worse estimates, indicating the importance of global scene consistency. In the second, computational experiment, we correlated the performance of several algorithms for horizon estimation with the human data—algorithms ranged from simple estimations of bright-dark-transitions to more sophisticated frequency spectrum analyses motivated by previous computational modeling of scene classification results. Correlations between human and computational estimates ranged from 0.2 to 0.6 and varied by algorithm and scene category. Overall, frequency spectrum analysis provided the best results, which taken together with the perceptual data, highlights the importance of global, frequency-based information in scene processing.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100067}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Herdtweck C{grueschaan}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Poster{ 6787, title = {No other-race effect found in a task using faces differering only in race-specifying information}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {90}, abstract = {Generally, faces of one’s own ethnicity are better remembered than faces of another race. The mechanisms of this other race effect (ORE) are still unresolved. The present study investigates whether expertise for own-race results in ORE in a discrimination task when only race-specifying information varies between faces, with no interference of identity change and no memory load. If expertise is an important factor for ORE, Caucasian participants, for example, should better discriminate between two Caucasian faces presented side by side than between two Asian faces. We tested participants in Seoul and Tübingen with pairs of Asian or Caucasian faces. Their task was to tell which face of the pair was either more Asian or more Caucasian. Although we found that Asian face pairs were unexpectedly but consistently better discriminated than Caucasian faces, this Asian advantage did not differ between both city groups. Our results show furthermore that Seoul and Tübingen participants’ discrimination performance was similar for Asian and Caucasian faces. These findings suggests that when there is no memory component involved in the task and when face appearance only differs in race-specifying information, own-race expertise does not result in better performance for own-race faces.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100038}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}, Lee RK{ryokyung}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ Schultz2010, title = {On the role of attention and eye movements for the perception of animacy from a single moving object}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {19}, abstract = {We previously developped stimuli allowing parametric control over the percept of animacy evoked by the movements of a single object, without contribution from spatial arrangement, shape or structure of the object (Schultz and Dopjans, 2008 Perception 35 ECVP Supplement, 154). As observers tend to follow the stimulus with their eyes while performing animacy judgments, we quantified these eye movements in the present study (Experiment 1). In Experiment 2, we tested the importance of eye movements and attention for task performance by forcing subjects to fixate while judging animacy. In Experiment 3, attentional resources were further reduced by asking subjects to perform a secondary task at fixation while judging animacy. Experiment 1 showed that the distance between eye fixations and the stimulus increased with changes in animacy, compatible with a greater difficulty in following animate-looking stimuli. Combined results across experiments show that the strength of the changes in percept tends to be reduced with fixed gaze and is significantly decreased in the dual-task setting. In the latter, the greatest disruption in stimulus processing appears to result from detecting and reporting the fixation targets rather than just splitting attentional resources. These results suggest that at least partially sustained attention is required for animacy judgments about our single moving dot stimulus.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100581}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action}} } @Poster{ 6508, title = {Path integration in the third dimension}, journal = {Journal of Vestibular Research}, year = {2010}, month = {8}, volume = {20}, number = {3-4}, pages = {282}, abstract = {Path integration, the ability to update the position and orientation of external locations predominantly on the basis of internal cues, is an effective strategy for spatial navigation. While extensive work has been done on evaluating path integration in the horizontal plane, little is known for movements in the vertical (third) dimension. Here we assess whether pointing to the origin of translational movement in vertical planes is similar to that found for movement in the horizontal plane alone. 15 observers sat upright in a racecar seat that was mounted to the flange of a modified KUKA c anthropomorphic robot arm (Fig. 1a). An LCD display was 50cm in front of the observers who were otherwise tested in the dark. Sensory information was manipulated by providing visual (optic flow, limited lifetime star field), vestibular-kinesthetic (passive self motion with eyes closed), or visual and vestibularkinesthetic motion cues. Movement trajectories consisted of two segment lengths (1st: 0.4 m, 2 nd: 1 m; ± 0.24 m/s2 peak acceleration). Movements in the horizontal, sagittal and frontal planes consisted of: forward-rightward (FR) or rightward-forward (RF), downward-forward (DF) or forward-downward (FD), and downward-rightward (DR) or rightward-downward (RD) movements respectively. The angle of the two segments was either 45◦ or 90◦. A 15 s pause preceded each trajectory. Observers pointed back to their origin by moving an arrow that was superimposed on an avatar presented on the screen (Fig. 1b). Movement of the arrow was constrained to the trajectory’s plane and controlled by a joystick. The avatarwas presented from frontal, sagittal and horizontal viewpoints. Observers were allowed to use any or all viewpoints to answer. The starting orientation of the arrow was randomized across trials. Each condition was repeated 3 times and presented in random order. Signed error and response time were analyzed as dependent variables. Observers were more likely to underestimate angle size (average data less than 0◦; Fig. 1c) for movement in the horizontal plane compared to the vertical planes. In the frontal plane observers were more likely on average to overestimate angle size (average data more than 0◦), while there was no such bias in the sagittal plane. Another discrepancy between horizontal and vertical planes was that responses in the vertical planes were more closely related to a response bias suggesting that the path segments were of equal length (solid grey line). Finally, observers responded slower (Fig. 1d) when answering based on vestibular-kinesthetic information alone. These results suggest that human path integration based on vestibular-kinesthetic information alone takes longer than when visual information is present. Path integration has been well established as a means used to resolve where an observer originated but is prone to underestimates of the angle one has moved through. Our results show this for translational movement but only within the horizontal plane. In the vertical planes pointing may have been directed in accordance with an assumption of equal path lengths. This result suggests that alternative strategies for determining one’s origin may be adopted when moving in the third dimension which may relate to the fact that humans experience movement mostly within the horizontal plane.}, web_url = {http://iospress.metapress.com/content/m2507728n2243114/fulltext.pdf}, event_name = {XXVI Bárány Society Meeting}, event_place = {Reykjavik, Iceland}, state = {published}, DOI = {10.3233/VES-2010-0374}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Vidal M{vidal}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ PrettoBB2010, title = {Perceptual quirk induces safe driving in fog}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {168}, abstract = {Perceived speed of moving patterns is lower when visual contrast is reduced. In recent driving simulation experiments, this has been presented as an explanation why drivers might drive too fast in fog. In this simulation, contrast was equally reduced for all objects in the scene, independently of their distance from observer (distance-independent contrast reduction). In fog, however, contrast is reduced more for more distant objects (distance-dependent contrast reduction). We compared the effects of these two types of contrast reduction on both perceived and actual driving speed. In the first experiment twelve participants were presented with pairs of driving scenes—one with clear visibility, one with reduced contrast—and instructed to estimate which scene moved faster. Speed was underestimated with distance-independent contrast reduction but overestimated with distance-dependent contrast reduction. In the second experiment, ten drivers drove at target speeds under clear and reduced visibility conditions without tachometer. Participants increased speed with distance-independent contrast reduction but decreased speed with distance-dependent contrast reduction. These results show how visibility loss can lead to opposite perceptual and behavioural effects, depending on the nature of the underlying visual contrast reduction. In fog, indeed, the visual system fools drivers the safe way, advising them to decelerate.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100256}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Pretto P{pretto}{Department Human Perception, Cognition and Action}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6637, title = {Predicting Change of Vestibular Direction Detection Thresholds from Acceleration Profile Differences}, journal = {Journal of Vestibular Research}, year = {2010}, month = {8}, volume = {20}, number = {3-4}, pages = {279-280}, abstract = {In the absence of vision, the perceived direction of translational self motion is largely governed by signals originating from the otoliths. Although it has been shown that direction detection thresholds depend on the frequency of the motion stimulus, the influence of the actual time course of the motion has not been thoroughly investigated. The goal of our study was to measure, model and predict vestibular direction detection thresholds for different motion profiles in the horizontal plane. Detection thresholds for three acceleration profiles, one sinusoidal and two non-sinusoidal (Fig. 1A), with three different durations were measured for six human participants. An anthropomorphic robot arm, the Max Planck CyberMotion Simulator, was used to provide the motion stimuli. The experiment was designed as a four-alternative forced-choice task, where blindfolded participants judged the direction of motion from four possibilities: forward, backward, left or right. Stimulus intensity (peak acceleration of the motion profile) was varied based on a Bayesian adaptive method, and a psychometric function fit to the measurements determined the sensory threshold. For modeling, a 2nd order linear dynamical system with two poles and one zero, originally proposed by Young and Meiry (1968), was used to describe the data. The parameters of this model have been previously identified with sinusoidal motion stimuli over a broad frequency range for similar tasks, but predictions concerning perceptual thresholds for general motion profiles are unknown. In our study, the thresholds obtained from the three sinusoidal acceleration profiles were used to identify the static gain of the model by fitting the system gain to the inverted thresholds. The other parameters were derived from the literature. Predicting the thresholds for general motion profiles was based on the assumption that the output of the model can be interpreted as the signal intensity coming from the otoliths and that if this intensity overcomes a certain value the correct direction of motion can be perceived. In order to predict the threshold, the peak acceleration of the input profile must be selected so that that the corresponding maximum model output is equal to one (Fig. 1B). Predictions for the remaining six non-sinusoidal profiles showed that they were in good agreement with the measured data, with the average error being smaller than 20% of the average detection threshold. This is a promising result, as just the static gain of the model was identified from only three data points. Accepting the linear model as a method to predict thresholds, it is also possible to fit the model to the nonsinusoidal profile data and identify the whole parameter set. Instead of fitting the system gain to the inverted sinusoidal thresholds, we computed the predictions for all profiles given a certain set of model parameters and iteratively varied the parameters to minimize the error between measurements and predictions. Two of the three identified model parameters agreed with the values given in the literature, while the third was found to be different. This difference suggested a phase lead for lower frequencies, which corresponds to sensitivity to jerk (the time derivative of acceleration). Comparing threshold predictions between models with different jerk sensitivities reveal distinct differences between the predictions at low frequencies. The predictions for a model with higher jerk sensitivity appear more appropriate and could be tested in future experiments. To summarize, we have shown that a linear model approach is able to predict vestibular perceptual direction detection thresholds. This allows the model parameters to be identified while resorting to non-sinusoidal stimuli, and helps to better understand vestibular linear motion perception. Future studies will extend these measurements to lower frequencies and assess this modeling approach for rotational movements.}, web_url = {http://iospress.metapress.com/content/m2507728n2243114/fulltext.html}, event_name = {XXVI Bárány Society Meeting}, event_place = {Reykjavik, Iceland}, state = {published}, DOI = {10.3233/VES-2010-0374}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Beykirch K{kab}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6419, title = {Recalibration of audiovisual simultaneity changes detection threshold to sound but not to light}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {187}, abstract = {Prolonged exposure to asynchronous audiovisual stimulus pairs changes the perception of audiovisual simultaneity. It has been proposed that this change occurs by adjusting the perceptual latency of stimuli in order to minimize perceived audiovisual asynchrony. How is this adjustment achieved? For signals with a gradual onset, perceptual latency can be minimized by decreasing detection threshold (or vice-versa). Here we assess whether this occurs following recalibration of simultaneity. Participants were exposed for 5 minutes to asynchronous (150ms) audiovisual stimulus pairs with either light or sound leading. Auditory stimuli were presented via headphones, visual via an LED. Detection thresholds for visual and auditory stimuli were then measured with a 2IFC task interleaved with short re-exposures to the asynchrony. Results indicate that while the detection threshold for visual stimuli does not significantly vary, the detection threshold for auditory stimuli critically depends on which modality leads during asynchronous audiovisual exposure. All nine participants tested were more sensitive in detecting auditory stimuli after light-leading exposure than after sound-leading. We suggest that by becoming more or less sensitive to sound the brain is able to change the perceptual latency of auditory stimuli to minimize audiovisual asynchrony, while keeping the perceptual latency of visual stimuli relatively constant.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100019}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}} } @Poster{ BrescianiTBB2011, title = {Rich 3D environments facilitate sensorimotor learning}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {50}, abstract = {Using a visuo-vestibular adaptation paradigm, we measured how the richness/realism of the visual scene affects sensorimotor learning. Participants seating on a motorized wheelchair had to maintain their stretched arm fixed in space despite whole-body rotations. After a test session in which body rotations occurred without visual information, participants were exposed to a visuo-vestibular adaptation, and then tested again in a test session identical to the first one. In the adaptation phase, biased visual information about motion amplitude was provided during body rotations via a head-mounted display, so that participants learned a biased visuo-vestibular mapping. Four different types of adaptation were used (with different participants). Specifically, we manipulated orthogonally the visual information relative to the own body (avatar arm vs sphere indicating fingertip position) and that relative to the surrounding environment (virtual room vs sphere). All four types of visual environments gave rise to a significant adaptation (p<0.05). Interestingly, the amplitude of the adaptation (both relative and absolute) was significantly larger only when the room and the arm were realistically displayed. These results suggest that for a sensorimotor learning facilitation to occur, both body-related and environment-related visual information must be realistic.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100258}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}, Tesch J{jtesch}{Department Human Perception, Cognition and Action}, Bischoff H{bischoff} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6550, title = {The effect of walking speed on the sensitivity to curved walking in an immersive Virtual Environment}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {96}, abstract = {People are relatively insensitive to the curvature of their walking trajectory [Kallie et al., 2007, JEP:HPP, 33(1), 183-200]. This is exploited in the "Redirected Walking" technique which is used in Virtual Reality to extend the borders of Virtual Environments (VE) beyond the size of the physical walking area [Steinicke et al., 2009, Journal of Virtual Reality and Broadcasting, 6(2009)]. One method is to slowly rotate the VE while the user is aiming to walk a straight path, inducing him/her to unknowingly walk on a curved trajectory. We tested whether the sensitivity to curvature depends on walking speed. Participants followed a virtual sphere in a VE, which moved on a straight path. During walking, the entire visual scene was rotated, creating a curved real-world trajectory (radius 20-200m). Walking speed was 0.75, 1.0, or 1.25 m/s. Participants indicated whether their physical walking path curved to the left or right. Discrimination thresholds were estimated by fitting a psychometric function to the propor tion of trials in which the trajectory was reported to curve to the left. Curvature thresholds were found to be higher for slow walking. This suggests that the effectiveness of the redirected walking technique depends on walking speed.}, file_url = {/fileadmin/user_upload/files/publications/Abstract%20ECVP10_[0].pdf}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100135}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Neth C{neth}{Department Human Perception, Cognition and Action}, Souman JL{souman}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Kloos U and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ 6537, title = {The impact of an animated avatar on egocentric distance perception in an immersive virtual environment}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {51}, abstract = {To date, few head-mounted display (HMD) virtual environment systems display a rendering of the user’s own body. Subjectively, this often leads to a sense of disembodiment in the VE. In a recent study, we found that the experience with a self-avatar changed the typical pattern of distance underestimation seen in many HMD studies (Mohler et al, in press Presence). Users showed an increase in distance estimations with avatar experience, especially when the avatar was animated in correspondence with their own body-movements. The effect occurred for both co-located self-avatars and self-avatars viewed from the third person perspective. The current study investigated the importance of the degree to which self-avatar animation reflected the actual movements of the user. We compared distance judgments with a third-person perspective view of a self-avatar that was either controlled by user motions or was animated based on pre-recorded motion data. The results suggest that experience with an animated avatar, even if not in correspondence with a user’s own body movements, increases distance estimates. The magnitude of this effect will be further examined with additional participants.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100133}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, Creen-Regehr SH, Thompson WB{wthompson} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ VolkovaABM2010, title = {Virtual storytelling of fairy tales: Towards simulation of emotional perception of text}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {31}, abstract = {Emotion analysis (EA) is a rapidly developing area in computational linguistics. For most EA systems, the number of emotion classes is very limited and the text units the classes are assigned to are discrete and predefined. The question we address is whether the set of emotion categories can be enriched and whether the units to which the categories are assigned can be more flexibly defined. Six untrained participants annotated a corpus of eight texts having no predetermined annotation units and using fifteen emotional categories. The inter-annotator agreement rates were considerably high for this difficult task: 0.55 (moderate) on average, reaching 0.82 (almost perfect) with some annotator pairs. The final application of the intended EA system is predominantly in the emotion enhancement of human–computer interaction in virtual reality. The system is meant to be a bridge between unprocessed input text and auditory and visual information: generated speech, animation of facial expressions and body language. The first steps towards integrating text-based information annotated for emotion categories and simulation of human emotional perception of texts in story telling scenarios for virtual reality are already made. We have created a virtual character, whose animation of face and body is driven by annotations in text.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100139}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Volkova EP{evolk}{Department Human Perception, Cognition and Action}, Alexandrova IV{ivelina}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ 6862, title = {Visual stimulus timing precision in Psychtoolbox-3: Tests, pitfalls and solutions}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {189}, abstract = {Visual stimulation paradigms in perception research often require accurate timing for presentation of visual stimuli. Acquisition of exact stimulus update timestamps in realtime is often crucial, both for synchronization of stimulus updates between different presentation modalities and for logging. Modern graphics hardware, multi-core processors and operating systems provide a far higher level of functionality, flexibility, and performance in terms of throughput, than systems a decade ago. They also pose new challenges for precise presentation timing or timestamping. Typical causes of interference are, eg the dynamic power management of modern graphics cards and computers, novel hybrid graphics solutions, user interface desktop composition and the properties of graphics- and CPU-scheduling of the latest generation of operating systems. This work presents results for the accuracy and robustness of visual presentation timing and timestamping tests, conducted within Psychtoolbox-3 (Kleiner et al, 2007 Perception 36 ECVP Supplement, 14) on different operating systems and graphics cards under realistic stimulus presentation loads. It explains some of the common pitfalls one can encounter when trying to achieve exact timing and some methods to avoid timing problems or reduce their severeness.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100546}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}} } @Poster{ 6751, title = {Whole-brain fMRI using repetition suppression between action and perception reveals cortical areas with mirror neuron properties}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {54}, abstract = {Mirror Neurons (MN) have been suggested to be the supporting neural mechanism for action recognition and understanding. However, there is a current debate about the localization of MN in humans. Functional magnetic resonance imaging (fMRI) studies using repetition suppression (RS) paradigms for the identification of MN provide mixed results. Studies supporting the existence of MN restricted their analysis to a-priori candidate regions, whereas studies that failed to find evidence used non-object-directed actions. In the present fMRI study, we tackled these limitations by using object-directed actions in a RS paradigm and performing a wholebrain analysis. Subjects observed and executed simple grasping movements differing only in their goal-directness (grasping a button vs. grasping beside it). MN areas should be (1) more activated by goal-directed actions and (2) exhibit RS between execution and observation of the same action. The analysis revealed three significant cortical clusters in the right anterior intraparietal sulcus (aIPS), right primary somatosensory cortex and left premotor cortex that show these characteristics. While the aIPS has been reported before as a possible region for MN, the other two clusters haven’t been associated with MN directly yet using RS paradigms. We discuss the potential contribution of these regions to object-directed actions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100476}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Schillinger F{frieder}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Schultz J{johannes}{Department Human Perception, Cognition and Action} and Uludag K} } @Poster{ 6847, title = {Neural Correlates of Online Control of Reaching Movements}, year = {2010}, month = {7}, web_url = {http://fens2010.neurosciences.asso.fr/pages/sub/SatellitesEvents.php}, event_name = {FENS 2010 Satellite Symposium on Motor Control}, event_place = {Nijmegen, Netherlands}, state = {published}, author = {Reichenbach A{areichen}{Department Human Perception, Cognition and Action}{Department High-Field Magnetic Resonance}, Thielscher A{thielscher}{Department High-Field Magnetic Resonance}, Peer A, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}} } @Poster{ SoykaBRB2010, title = {Predicting Vestibular Direction Detection Thresholds for Translatory Motions}, year = {2010}, month = {7}, web_url = {http://www.brain.riken.jp/en/summer/previous.html}, event_name = {RIKEN Brain Science Institute Summer School 2010}, event_place = {Tokyo, Japan}, state = {published}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Beykirch K{kab}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6498, title = {An invisible signal can be made accessible to consciousness by training the perceptual system to use it for a novel purpose}, year = {2010}, month = {6}, volume = {4}, pages = {8-9}, abstract = {The perceptual appearance of a visual stimulus can be changed by presenting stimuli that are similar, but that differ along specific dimensions, to the observer in advance. Many negative adaptation aftereffects are familiar to students of perception, for example. A different example is “cue recruitment” (Haijiang et al., 2006): a visual signal that has no effect on some attribute of appearance can often be made to affect that attribute through the use of classical (Pavlovian) conditioning procedures. In that case, the signal has come to be treated as a new cue by the visual system, insofar as it now participates in the construction of some new aspect of appearance that it previously did not. We asked whether this learning requires that the signal be visible, i.e. whether it must have a consciously accessible perceptual consequence, of any sort, during training. To do this we employed an invisible visual signal, namely, a vertical gradient of vertical disparity obtained by slightly magnifying the image in one eye. This signal is measured by the visual system, but it had no influence on any of the perceptual attributes that observers’ visual systems computed from the displays, in which horizontal lines depicted a rotating cylinder. During training we made the eye of vertical magnification (EVM) contingent on the rotation direction of the cylinder. After training we presented an ambiguous version of the cylinder and found that EVM influenced the perceived direction of rotation consistent with contingency during training. Thus, a signal need not be visible for the adult visual system to give it new use as a participant in the construction of visual appearances. Haijiang, Q., Saunders, J. A., Stone, R. W., & Backus, B. T. (2006). Demonstration of cue recruitment: Change in visual appearance by means of Pavlovian conditioning. PNAS, 103, 483–486.}, web_url = {http://www.theassc.org/the_4th_annual_meeting_of_the_association_for_the_scientific_study_of_consciousness_assc_4}, event_name = {4th Annual Meeting of the Association for the Scientific Study of Consciousness (ASSC 4)}, event_place = {Brussels, Belgium}, state = {published}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Ernst MO{marc}{Research Group Multisensory Perception and Action} and Backus BT{backus}} } @Poster{ 6570, title = {Audio-visual interactions in binocular rivalry using the Shepard illusion in the auditory and visual domain}, year = {2010}, month = {6}, volume = {11}, number = {229}, abstract = {When both eyes are presented with dissimilar images, human observers report alternating percepts - a phenomenon known as binocular rivalry. Subjects were presented dichoptically with (1) a looming/receding starfield or (2) a looming/receding Shepard Zoom (Berger, Siggraph 2003), the visual equivalent of the Shepard tone illusion. In four psychophysical experiments, we investigated the influence of (1) a real complex tone rising/falling in pitch and (2) rising/falling Shepard tones on the dominance and suppression times of the rivaling visual motion percepts (relative to non-motion sounds or no sounds). First, we observed longer dominance times of looming than receding visual percepts even in the absence of sound. Second, auditory looming signals enhanced this looming bias by lengthening the dominance periods of their congruent visual looming percept. Third, receding auditory motion signals reduced the perceptual looming bias, though this effect was less pronounced and not consistently observed. Collectively, the results show that the perceptual predominance of looming relative to receding visual motion is amplified by congruent looming/receding auditory signals during binocular rivalry. Auditory looming/receding signals may influence the dominance times of their congruent and incongruent visual percepts via genuine multisensory and higher order attentional mechanisms at multiple levels of the cortical hierarchy.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/229}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Conrad V{conrad}{Department Human Perception, Cognition and Action}, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}, Hartcher-O‘Brien J{jhartcher}, Bartels A{abartels}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Noppeney U{unoppe}} } @Poster{ 6818, title = {Categorical Representation of a Human/Monkey Face Continum in the Human and Non-Human Primate Temporal Lobe}, year = {2010}, month = {6}, volume = {2010}, pages = {93}, abstract = {Categorization of faces is fundamental for social interactions of primates. To understand its neural basis, we investigate how human and monkey face categories are represented in both the human and non-human primate brain. As stimuli, we use realistic three-dimensional morphed faces that linearly span the continuum between humans and monkeys (Fig. 1A). Extensive behavioral tests in both species revealed categorical perception with a shift of the categorical boundary towards the own species (Fig. 1B). This suggests that both species perceive the same stimulus continuum in a fundamentally different way. During a fixation task, we recorded from the temporal lobe extracellular signals in monkeys and BOLD signals in humans. To analyze the data, we used a multivariate pattern classifier approach based on Support Vector Machines and correlations. Consistent with the psychophysical results, we found an "own-species" bias in the categorical representation of human and monkey faces at the level of single neurons as well as in the population response in the inferior temporal lobe of the monkey. (Fig. 1C). Symmetrically, we found a categorical response with an ownspecies bias in the activation patterns of the left human STS. In addition, human ventral temporal cortex showed a higher sensitivity for human faces. Our results are the first to demonstrate the neural basis of categorical representation of a facial attribute in the primate brain. In addition, our data show that both psychophysical and neuronal data can show categorical boundary shifts indicative of the behavioral relevance of prototypical categories.}, web_url = {http://www.areadne.org/2010/home.html}, editor = {Hatsopoulos, N. G., S. Pezaris}, event_name = {AREADNE 2010: Research in Encoding And Decoding of Neural Ensembles}, event_place = {Santorini, Greece}, state = {published}, author = {Sigala R{sigala}{Department Physiology of Cognitive Processes}, Schultz J{johannes}{Department Human Perception, Cognition and Action}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes} and Rainer G{gregor}} } @Poster{ 6421, title = {Change of the "light-from-above" prior when the body is tilted relative to gravity}, year = {2010}, month = {6}, volume = {11}, number = {114}, abstract = {In environments where orientation is ambiguous, the visual system uses prior knowledge about lighting coming from above to recognize objects, reorient the body, and determine which way is up (where is the sun?). It has been shown that when observers are tilted to the side relative to gravity, the orientation of the light-from-above prior will change in a direction between the orientation of the body, gravity and the visual surround. The contribution of ocular torsion in this change of the light-from-above prior has been acknowledged but not specifically addressed. Here we test the hypothesis that when lighting direction is the only available visual orientation cue, change in orientation of the light-from-above prior is accounted for by ocular torsion. Observers made convex-concave judgments of a central shaded disk, flanked by three similarly- and three oppositely-shaded disks. Lighting was tested every 15° in roll in the fronto-parallel plane. Observers were tested when upright, supine, and tilted every 30 ° in role relative to gravity. Our results show that change of the light-from-above prior is well predicted from a sum of two sines; one consistent with predicted ocular torsion, the other consistent with an additional component varying with twice the frequency of body tilt.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/114}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Ernst MO{marc}{Research Group Multisensory Perception and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6568, title = {Emotional information enhances audiovisual speech integration}, year = {2010}, month = {6}, volume = {11}, number = {377}, abstract = {Affective information constitutes a key feature of audiovisual speech and plays a fundamental role in everyday communication and consequent social interactions. In spite of the perceptual saliency of affective information, however, its role in the audiovisual integration of speech has not, as yet, received much attention from researchers interested in multisensory perception. Here, we investigated the effects of affective content on audiovisual speech integration. Participants were presented with pairs of spatially discrepant auditory and visual speech stimuli conveying various emotional states. To measure the impact of affective valence on multisensory integration, participants were asked to report the relative spatial location of the auditory speech with respect to that of the visual, speaking face. In Experiment 1, the reliability of participants‘ estimates was lower for both angry and fearful audiovisual speech stimuli compared to emotionally neutral stimuli. In Experiment 2, the reliability of estimates was lower for both fearful and happy stimuli compared to neutral. Reduced reliability of perceptual estimates regarding intersensory conflict indicates a stronger coupling between unisensory signals. Therefore, these results imply a stronger coupling of audiovisual stimuli sharing positive or negative emotional tone, and provide the first psychophysical evidence for the role of affective information in multisensory integration.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/377}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Parise CV{cesare}{Research Group Multisensory Perception and Action}, Stewart N, F\"ocker J, Ngo M, Browning M, Roeder B, Spence C and Rogers RD} } @Poster{ SchultzB2010, title = {How does the brain identify living things based on their motion?}, year = {2010}, month = {6}, volume = {16}, number = {194 MT-PM}, pages = {62}, web_url = {http://www.humanbrainmapping.org/i4a/pages/index.cfm?pageid=3342}, event_name = {16th Annual Meeting of the Organisation for Human Brain Mapping (HBM 2010)}, event_place = {Barcelona, Spain}, state = {published}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6658, title = {It's All Me: Varying Viewpoints and Motor Learning in a Virtual Reality Environment}, year = {2010}, month = {6}, volume = {11}, number = {350}, abstract = {In the present study, healthy subjects performed a visuo-vestibular motor adaptation task in virtual reality. The task consisted of keeping the extended arm and hand stable in space during a whole-body rotation induced by a robotic wheelchair. Performance was first quantified in a pretest in which no visual feedback was available during the rotation. During the subsequent learning phase optical flow resulting from body rotation was provided. This visual feedback was manipulated to create the illusion of a smaller rotational movement than actually occurred, hereby altering the visuo-vestibular mapping. The adaptation effects of the learning phase were measured during a posttest identical to the pretest. Three different groups of subjects were exposed to different perspectives on the visual scene, i.e., first-person-, top- or mirror-view. Interestingly, sensorimotor adaptation occurred for all three viewpoint conditions (p < 0.05). Furthermore, in the mirror-view participants showed significantly less variability in performance. These results suggest that the visually richer mirror-view enhanced motor learning relative to the other viewpoints. Therefore, using virtual reality to provide rich multimodal stimulation including mirror views could add to traditional neurorehabilitation techniques by facilitating motor learning.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/350}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Schomaker J{jschomaker}{Department Human Perception, Cognition and Action}, Tesch J{jtesch}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}} } @Poster{ 6420, title = {Latent reaction time and event-related potentials to passive physical motion}, year = {2010}, month = {6}, volume = {11}, number = {111}, abstract = {Involuntary physical responses to vestibular stimulation are very fast. The vestibulo-ocular reflex, for example, occurs approximately 20ms after the onset of vestibular stimulation (Lorente de No, 1933, Arch Neurol Psychiat). Despite these fast responses, reaction time (RT) to the perceived onset of vestibular stimulation occurs as late as 438ms after galvanic vestibular stimulation, which is approximately 220ms later than RTs to visual, somatosensory and auditory stimuli (Barnett-Cowan & Harris, 2009, Exp Brain Res). To determine whether RTs to natural vestibular stimulation are also slow, participants in the present study were passively moved forwards by .1178m (single cycle sinusoidal acceleration; 0.75m/s/s peak acceleration) using a Stewart motion platform and were asked to press a button relative to the onset of physical motion. RTs to auditory and visual stimuli were also collected. RTs to physical motion occurred significantly later (>100ms) than RTs to auditory and visual stimuli. Event related potentials (ERPs) were simultaneously recorded where the onset of the vestibular-ERP in both RT and non-RT trials occurred about 200ms or more after stimulus onset while the onset of the auditory- and visual-ERPs occurred less than 100ms after stimulus onset. All stimuli ERPs occurred approximately 135ms prior to RTs. These results provide further evidence that vestibular perception is slow compared to the other senses and that this perceptual latency may be related to latent cortical responses to physical motion.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/111}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Nolan H, Butler JS{butler}{Department Human Perception, Cognition and Action}, Foxe JJ, Reilly RB and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6497, title = {Multiple criteria for multisensory signals}, year = {2010}, month = {6}, volume = {11}, number = {374}, abstract = {Perceptual judgments are classically regarded as involving both a sensory and a decisional component. An optimal observer engaged in a signal detection task should maximize the correct responses by setting an appropriate decisional criterion according to his/her sensitivity to sensory signals. A large body of literature supports the view that observers set a near-optimal criterion in the detection of a single signal. However, there seems to be a systematic deviation from optimality when observers are required to concurrently judge multiple signals within the visual modality. In this case, observers set only a single criterion for the joint presentation of the compound signals (Gorea & Sagi 2000). This result has been interpreted as an indication that humans are unable to simultaneously handle multiple signal representations within a sensory modality. Literature, however, remains silent as to the crossmodal case. In a 2IFC task we asked participants to concurrently report whether or not visual and/or auditory stimuli changed position within each trial. Our results show that with multisensory signals observers can simultaneously set separate criteria for each modality. It is still an open question whether separate criteria are also set when multisensory signals are integrated.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/374}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Parise CV{cesare}{Research Group Multisensory Perception and Action}, Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Poster{ 6659, title = {Multisensory Self-Motion Oddball Paradigm Evokes a P3 Response}, year = {2010}, month = {6}, volume = {11}, number = {370}, abstract = {Introduction: The sensation of motion is a product of the integration of information from multiple sensory modalities; vestibular, visual and proprioceptive information all have strong influences on the perception of self-motion. Here we present an electroencephalogram (EEG) study which demonstrates a P3 response to a self-motion oddball paradigm. Methods: Subjects were placed in a Maxcue Stewart motion platform. Auditory and visual cues were minimised using white noise and an enclosed environment. They were translated linearly 7cm using a 1s long sinusoidal acceleration profile at a 45° angle forwards and left or right, with a probability of 0.8 / 0.2, balanced over runs (oddball paradigm). Subjects responded to the infrequent direction by pressing a button. During the task, EEG data were recorded using a Biosemi ActiveTwo 128-channel EEG system. The recordings were processed offline to remove artifacts. Results / Conclusion: Statistical parametric mapping shows the frequent and infrequent event-related potentials (ERPs) to differ significantly from 500ms - 950ms. Topographic analysis shows a typical P3 topography. Response-epoched ERPs show a peak of width approx 300ms. Conclusion: These results indicate that a P3-like response is generated by the motion oddball paradigm.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/370}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Nolan H, Whelan R, Butler J{butler}{Department Human Perception, Cognition and Action}, Foxe J, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Reilly RB} } @Poster{ 6660, title = {Nonlinear temporal distortions in vision and audition}, year = {2010}, month = {6}, volume = {11}, number = {393}, abstract = {Perceived time is not veridical but distorted and differs across the senses. Here we ask, which points in the perception of a temporal event contribute most significantly to these multisensory distortions? To this end, we investigated perceptual estimates of temporal landmarks (onset, peak amplitude, and offset) for a Gaussian standard signal (s=150ms). Particularly we were interested in how the perception of these landmarks differ across vision and audition. Participants undertook a temporal order judgment task comparing the onset, peak and offset landmarks of the standard stimuli to short spike-like stimuli (s=5ms) in vision or audition. All four combinations were tested: V-v, A-a, V-a, A-v. Results demonstrate that the visual as compared to auditory standard stimuli were perceived shorter. More interestingly, we found a compression in the perceived duration for onset-peak intervals compared to peak-offset intervals. This compression effect was more pronounced in the visual modality. Discrimination threshol ds were worse for offset judgements compared to onset or peak judgements in both modalities. The differences in perceived duration can potentially be used to explain multisensory illusions such as the flash lag effect and perceived crossmodal asynchronies. We quantitatively explain these distortion effects using models of signal processing.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/393}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Hartcher-O‘Brien J{jhartcher}{Research Group Multisensory Perception and Action}, Telgen S{telgen}{Research Group Multisensory Perception and Action}, Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Poster{ 6422, title = {Perceived stability of objects changes when the body is tilted relative to gravity}, year = {2010}, month = {6}, volume = {11}, pages = {113}, abstract = {Knowing an object's physical stability affects our expectations about its behaviour and our interactions with it. Objects topple over when the gravity-projected centre-of-mass (COM) lies outside the support area. The critical angle (CA) is the orientation for which an object is perceived to be equally likely to topple over or right itself, which is influenced by global shape information about an object's COM and its orientation relative to gravity. When observers lie on their sides, the perceived direction of gravity is tilted towards the body. Here we test the hypothesis that the CA of falling objects is affected by this internal representation of gravity. Observers sat upright or lay left- or right-side-down, and observed images of objects with different 3D mass distributions that were placed close to the right edge of a table in various orientations. Observers indicated whether the objects were more likely to fall back onto or off the table. The subjective visual vertical was also tested as a measure of perceived gravity. Our results show the CA increases when lying right-side-down and decreases when left-side-down relative to an upright posture, consistent with estimating the stability of rightward falling objects as relative to perceived and not physical gravity.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/113}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Fleming RW{roland}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6846, title = {Proprioceptive online control of goal-directed reaching: a transcranial magnetic stimulation study}, year = {2010}, month = {6}, volume = {16}, number = {1259 MT-AM}, pages = {45}, web_url = {http://www.humanbrainmapping.org/files/2010MeetingFiles/OHBM%202010%20Abstract%20Book.pdf}, event_name = {16th Annual Meeting of the Organisation for Human Brain Mapping (HBM 2010)}, event_place = {Barcelona, Spain}, state = {published}, author = {Reichenbach A{areichen}{Department Human Perception, Cognition and Action}{Department High-Field Magnetic Resonance}, Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}, Peer A, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Thielscher A{thielscher}{Department High-Field Magnetic Resonance}} } @Poster{ 6661, title = {The "impaired" internal representation of the body in Parkinson's disease}, year = {2010}, month = {6}, volume = {11}, number = {44}, abstract = {Perception of the relative orientation of the self, and objects in the environment, requires integration of visual and vestibular sensory information, and an internal representation of the body's orientation. Here I present and discuss findings on the relative contribution of these cues for orientation perception in Parkinson’s disease (PD; Barnett-Cowan et al., Neuroscience, In Press). The orientation of a line relative to vertical (i.e., subjective visual vertical) and the orientation in which a letter character is perceived as the ‘right way up’ (i.e., the perceptual upright) were measured in PD patients (on- and off-medication) and age-matched controls. Visual, vestibular and body cues were manipulated using a polarized visual room presented in various orientations while observers were upright or lying right-side-down. Patients were more influenced by vision than controls but only when setting a line to vertical. Patients relied less on the internal representation of the body when identifying characters as indicated by a greater influence of vestibular information. Consistent with reports of impaired proprioception among medicated PD patients, our effects were significant only when patients were medicated. I will discuss these results within a framework suggesting that this ‘impaired’ internal representation of the body may reflect physiological impairments in PD.}, web_url = {http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/44}, event_name = {11th International Multisensory Research Forum (IMRF 2010)}, event_place = {Liverpool, UK}, state = {published}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Dyde RT, Fox SH, Moro E, Hutchison WD and Harris LR} } @Poster{ 6581, title = {A Computational Mid-Level Vision Approach For Shape-Specific Saliency Detection}, journal = {Journal of Vision}, year = {2010}, month = {5}, volume = {10}, number = {7}, pages = {1160}, abstract = {We present a novel computational approach to visual saliency detection in dynamic natural scenes based on shape centered image features. Mid-level features, such as medial features, have been recognized as important entities in both human object recognition and in computational vision systems [Tarr & Buelthoff 1998, Kimia 2003]. [Kienzle et al 2009] have shown how image driven gaze predictors can be learned from fixations during free viewing of static natural images and result in center-surround receptive fields. Method: Our novel shape-centered vision framework provides a measure for visual saliency, and is learning free. It is based on the estimation of singularities of long ranging gradient vector flow (GVF) fields that have originally been developed for the alignment of image contours [Xu & Prince 1998]. The GVF uses an optimization scheme to guarantee preservation of gradients at contours and, simultaneously, smoothness of the flow field. The specific properties are similar to filling-in processes in the human brain. Our method reveals the properties of medial-feature shape transforms and provides a mechanism to detect shape specific information, local scale, and temporal change of scale, in clutter. The approach generates a graph which encodes the shape across a scale-space for each image. Results: We have made medial-feature transforms amenable to work in cluttered environments and have demonstrated temporal stability thus providing a mechanism to track shape over time. The approach can be used to model eye tracking data in dynamic scenes. A fast implementation will provide a useful tool for predicting shape-specific saliency at interactive framerates.}, web_url = {http://www.journalofvision.org/content/10/7/1160.abstract}, event_name = {10th Annual Meeting of the Vision Sciences Society (VSS 2010)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/10.7.1160}, author = {Curio C{curio}{Department Human Perception, Cognition and Action} and Engel D{engel}{Department Human Perception, Cognition and Action}} } @Poster{ 6490, title = {Audiovisual integration: the duration of uncertain times}, journal = {Journal of Vision}, year = {2010}, month = {5}, volume = {10}, number = {7}, pages = {1408}, abstract = {Despite continual temporal discrepancies between sensory inputs, signals arising from the same event are bound together into a coherent percept. It has been suggested that multiple timekeepers monitor the different sensory streams, producing differences in perceived duration of events. Given this, what is the integration strategy adopted for combining sensory information in the time domain? Specifically, if the brain has information about the duration of an event from more than one source, can the uncertainty of the duration estimate decrease, and can the Maximum Likelihood Estimate (MLE) model predict such a change? Using a 2AFC procedure, participants had to judge which interval was longer (1st or 2nd) for auditory, visual and audiovisual stimuli. Each trial contained 2 intervals: a standard stimulus (sampled from one of three durations), and a comparison interval whose duration changed randomly in relation to standard stimulus duration. The reliability of the auditory stimulus was manipulated to produce the unimodal weighting scheme. Data was fit with a cumulative Gaussian psychometric function from which PSE and JND were extracted. Results for unimodal trials showed JND changes that depended upon the duration of the standard, according to Weber's law. JND values also decreased with decreases in signal noise. Comparison of the present bimodal results with MLE predictions revealed optimal integration of auditory and visual duration cues. Additionally the results show that the integration of uncertain visual and auditory duration signals is a weighted average of these signals. That is, PSE shifts in perceived duration tended to reflect MLE predictions with shifts following the more reliable unimodal signal. These results are the first to demonstrate ‘optimal’ integration of sensory information in the time domain and contradict other studies applying MLE to this stimulus feature.}, web_url = {http://www.journalofvision.org/content/10/7/1408.abstract}, event_name = {10th Annual Meeting of the Vision Sciences Society (VSS 2010)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/10.7.1408}, author = {Hartcher-O'Brien J{jhartcher}{Research Group Multisensory Perception and Action}, Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Poster{ 6488, title = {Does audiovisual temporal recalibration store without stimulation?}, journal = {Journal of Vision}, year = {2010}, month = {5}, volume = {10}, number = {7}, pages = {1414}, abstract = {Recent studies have investigated adaptation to temporal discrepancies between different sensory modalities by first exposing participants to asynchronous multisensory signals, and subsequently assessing the magnitude of the adaptation effect (the size of the shift in subjective simultaneity). Although never reported, there is reason to assume that the strength of the adaptation effect declines during this measurement period. Usually, short re-exposures are interleaved with testing to prevent such declining. In the present study, we show that a decrease in the strength of adaptation still can take place, even when a common re-exposure procedure is used. In a second experiment, we investigated whether the observed decline is due to: (1) a dissipation of adaptation with the passage of time or, (2) a new adaptation induced by the test stimuli. We find that temporal adaptation does not dissipate with time but is stored until new sensory information, i.e., stimuli that differ from those used during the adaptation procedure, is presented. An alternative explanation, namely that adaptation decays over time but is re-established before the first test trial due to the experimental procedure we chose, is addressed in a control experiment. This finding is discussed in terms of Helson's adaptation level (AL) theory [1947, Adaptation-level as frame of reference for prediction of psychophysical data. The American Journal of Psychology, 60, 1–29], according to which the null point of any perceptual dimension, in our case the perception of simultaneity on the dimension of temporal order, is a summarizing statistic of all stimuli presented in the past. Any single stimulus pulls the AL toward its own value, and any single stimulus is judged as though it was being compared with the current AL.}, web_url = {http://www.journalofvision.org/content/10/7/1414}, event_name = {10th Annual Meeting of the Vision Sciences Society (VSS 2010)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/10.7.1414}, author = {Machulla T{tonja}{Research Group Multisensory Perception and Action}, Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action} and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Poster{ 6582, title = {Factors Influencing The Detectability Of Pedestrians In Urban Environments}, journal = {Journal of Vision}, year = {2010}, month = {5}, volume = {10}, number = {7}, pages = {1247}, abstract = {Driver assistance systems based on computer vision modules aim to provide useful information for the driving task to its user. One critical task in such scenarios is avoiding dangerous encounters between cars and vehicles. Classical computer vision systems aim only at finding all pedestrians. We propose that in order to provide the maximally useful information to the driver, it is also necessary to know the probability that the driver will see the pedestrian. This way the system is able to direct and modulate the attention of the driver towards pedestrians that he might not have noticed. Methods: We performed an experiment with 10 subjects. We showed images of urban environments for 120 ms followed by a noise mask. Afterwards, subjects had to indicate positions where they saw a pedestrian. We used the MIT StreetScenes database [1] which contains 3547 photos with hand-labeled pedestrian positions. Each participant was shown a total of 557 images in a random order. 142 images without pedestrians, 245 contained one single pedestrians and the rest contained two or more pedestrians. Results: We counted mouse clicks within a 100 pixel radius of the center of a pedestrian as hits. The average hit rate was 69%. We evaluated how well a classifier can predict the detectability of a pedestrian based on several features such as: compositional features (position and size of the pedestrian), image features (color histograms, contrast and histogram of oriented gradients descriptors of the pedestrian as well as the decision value of a support vector machine trained on a pedestrian classification task) and context features (difference in mean, standard deviation and color histograms between pedestrian and background and distance to other pedestrians in the image).}, web_url = {http://www.journalofvision.org/content/10/7/1247.abstract}, event_name = {10th Annual Meeting of the Vision Sciences Society (VSS 2010)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/10.7.1247}, author = {Engel D{engel}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Poster{ 6489, title = {Influence of asynchrony on the perception of visual-haptic compliance}, journal = {Journal of Vision}, year = {2010}, month = {5}, volume = {10}, number = {7}, pages = {852}, abstract = {Compliance of deformable materials is perceived through signals about resistive force and displacement. During visual-haptic interactions, visual and proprioceptive signals about material displacement are combined over time with the force signal. Here we asked whether multisensory compliance perception is affected by the timing of signals by introducing an asynchrony between the participant's movement (sensed proprioceptively) and force information or visual information. Visual-proprioceptive asynchronies are obtained by making participants see a delayed video of their haptic interaction with an object rather than the real interaction. Force-proprioceptive asynchronies are instead obtained by making participants compress a virtual object with their hand and sense the resistive force generated by a force feedback device. Results indicate that force-proprioceptive asynchronies can significantly alter the perception of object stiffness. Moreover, we find that perceived compliance changes also as a function of the delay of visual information. These effects of asynchrony on perceived compliance would not be present if all force-displacement information would be utilized equally over time, as both delays generate a bias in compliance which is opposite in the compression and release phases of the interaction. To explain these findings we hypothesized instead that information during object compression is weighted more than information obtained during object release and that visual and proprioceptive information about the hand position are used for compliance perception depending on the relative reliability of the estimate obtained. We confirm these hypotheses by showing that sensitivity to compliance is much higher during object compression and that degradation of visual and proprioceptive information can modify the weights assigned to the two sources. Moreover, by analyzing participants' movements and feedback forces we show that the two hypothesized factors (compression-release and visual-proprioceptive reliability) can account for the change in perceived compliance due to force-proprioceptive and force-displacement asynchronies.}, web_url = {http://www.journalofvision.org/content/10/7/852.abstract}, event_name = {10th Annual Meeting of the Vision Sciences Society (VSS 2010)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/10.7.852}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Kn\"orlein B, Harders M and Ernst MO{marc}{Research Group Multisensory Perception and Action}} } @Poster{ 6739, title = {Laying the foundations for an in-depth investigation of the whole space of facial expressions}, journal = {Journal of Vision}, year = {2010}, month = {5}, volume = {10}, number = {7}, pages = {606}, abstract = {Facial expressions form one of the most important and powerful communication systems of human social interaction. They express a large range of emotions but also convey more general, communicative signals. To date, research has mostly focused on the static, emotional aspect of facial expression processing, using only a limited set of “generic” or “universal” expression photographs, such as a happy or sad face. That facial expressions carry communicative aspects beyond emotion and that they transport meaning in the temporal domain, however, has so far been largely neglected. In order to enable a deeper understanding of facial expression processing with a focus on both emotional and communicative aspects of facial expressions in a dynamic context, it is essential to first construct a database that contains such material using a well-controlled setup. We here present the novel MPI facial expression database, which contains 20 native German participants performing 58 expressions based on pre-defined context scenarios, making it the most extensive database of its kind to date. Three experiments were performed to investigate the validity of the scenarios and the recognizability of the expressions. In Experiment 1, 10 participants were asked to freely name the facial expressions that would be elicited given the scenarios. The scenarios were effective: 82% of the answers matched the intended expressions. In Experiment 2, 10 participants had to identify 55 expression videos of 10 actors. We found that 34 expressions could be identified reliably without any context. Finally, in Experiment 3, 20 participants had to group the 55 expression videos of 10 actors based on similarity. Out of the 55 expressions, 45 formed consistent groups, which highlights the impressive variety of conversational expressions categories we use. Interestingly, none of the experiments found any advantage for the universal expressions, demonstrating the robustness with which we interpret conversational facial expressions.}, web_url = {http://www.journalofvision.org/content/10/7/606}, event_name = {10th Annual Meeting of the Vision Sciences Society (VSS 2010)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/10.7.606}, author = {Kaulard K{kascot}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action}, Cunningham DW{dwc}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6728, title = {Race-specific norms for coding face identity and a functional role for norms}, journal = {Journal of Vision}, year = {2010}, month = {5}, volume = {10}, number = {7}, pages = {706}, abstract = {High-level perceptual aftereffects have revealed that faces are coded relative to norms that are dynamically updated by experience. The nature of these norms and the advantage of such a norm-based representation, however, are not yet fully understood. Here, we used adaptation techniques to get insight into the perception of faces of different race categories. We measured identity aftereffects for adapt-test pairs that were opposite a race-specific average and pairs that were opposite a ‘generic’ average, made by morphing together Asian and Caucasian faces. Aftereffects were larger following exposure to anti-faces that were created relative to the race-specific (Asian and Caucasian) averages than to anti-faces created using the mixed-race average. Since adapt-test pairs that lie opposite to each other in face space generate larger identity aftereffects than non-opposite test pairs, these results suggest that Asian and Caucasian faces are coded using race-specific norms. We also found that identification thresholds were lower when targets were distributed around the race-specific norms than around the mixed-race norm, which is also consistent with a functional role for race-specific norms.}, web_url = {http://www.journalofvision.org/content/10/7/706.abstract}, event_name = {10th Annual Meeting of the Vision Sciences Society (VSS 2010)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/10.7.706}, author = {Armann RGM{armann}{Department Human Perception, Cognition and Action}, Jeffery L, Calder A, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action} and Rhodes G} } @Poster{ 6212, title = {Reaction time and event-related potentials to visual, auditory and vestibular stimuli}, journal = {Journal of Vision}, year = {2010}, month = {5}, volume = {10}, number = {7}, pages = {1400}, abstract = {Involuntary physical responses to vestibular stimulation are very fast. The vestibulo-ocular reflex, for example, occurs approximately 20ms after the onset of vestibular stimulation (Lorente de No, 1933, Arch Neurol Psychiat). Despite these fast responses, reaction time (RT) to the perceived onset of vestibular stimulation occurs as late as 438ms after galvanic vestibular stimulation, which is approximately 220ms later than RTs to visual, somatosensory and auditory stimuli (Barnett-Cowan & Harris, 2009, Exp Brain Res). To determine whether RTs to natural vestibular stimulation are also slow, participants in the present study were passively moved forwards by .1178m (single cycle sinusoidal acceleration; 0.75m/s/s peak acceleration) using a Stewart motion platform and were asked to press a button relative to the onset of physical motion. RTs to auditory and visual stimuli were also collected. RTs to physical motion occurred significantly later (>100ms) than RTs to auditory and visual stimuli. Event related potentials (ERPs) were simultaneously recorded where the onset of the vestibular-ERP in both RT and non-RT trials occurred about 200ms or more after stimulus onset while the onset of the auditory- and visual-ERPs occurred less than 100ms after stimulus onset. All stimuli ERPs occurred approximately 135ms prior to RTs. These results provide further evidence that vestibular perception is slow compared to the other senses and that this perceptual latency may be related to latent cortical responses to physical motion.}, web_url = {http://www.journalofvision.org/content/10/7/1400.abstract}, event_name = {10th Annual Meeting of the Vision Sciences Society (VSS 2010)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/10.7.1400}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}, Nolan H, Butler JS{butler}{Department Human Perception, Cognition and Action}, Foxe JJ, Reilly RB and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6579, title = {Reverse Correlation In Temporal Facs Space Reveals Diagnostic Information During Dynamic Emotional Expression Classification}, journal = {Journal of Vision}, year = {2010}, month = {5}, volume = {10}, number = {7}, pages = {700}, abstract = {Reverse correlation experiments have previously revealed the locations of facial features crucial for recognition of different emotional expressions, and related these features to brain electrophysiological activity [SchynsEtal07]. However, in social perception we expect the generation and encoding of communicative signals to share a common framework in the brain [SeyfarthCheney03] and neither ‘Bubbles’ [GosselinSchyns03] nor white noise based manipulation effectively target the input features underlying facial expression generation - the combined activation of sets of facial muscles over time. [CurioEtal06] propose a motion-retargeting method that controls the appearance of facial expression stimuli via a linear 3D Morphable Model [BlanzVetter99] composed of recorded Action Units (AUs). Each AU represents the surface deformation of the face, given the full activation of a particular muscle or muscle group taken from the FACS [EkmanFriesen79] system. The set of weighted linear combinations of AUs are hypothesised as a generative model for the set of typical facial movements for this actor. Here we report the outcome of a facial emotion reverse correlation experiment with one such generative AU model over a space of temporally parameterized AU weights. On each trial, a random selection of between 1 and 5 AUs are selected. Random timecourses for selected AUs are generated according to 6 temporal parameters (see supplementary figure). The observer rates the stimulus for each of the 6 ‘universal emotions’ on a continuous confidence scale from 0 to 1 and, from these ratings, optimal AU timecourses (timecourses whose temporal parameters maximize the expected rating for a given expression) are derived per expression and AU. These are then fed as weights into the AU model to reveal the feature dynamics associated with the expression. This method extends Bubbles and reverse correlation techniques to a relevant input space – one that makes explicit hypotheses about the temporal structure of diagnostic information.}, web_url = {http://www.journalofvision.org/content/10/7/700.abstract}, event_name = {10th Annual Meeting of the Vision Sciences Society (VSS 2010)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/10.7.700}, author = {Garrod O, Yu H, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, Curio C{curio}{Department Human Perception, Cognition and Action} and Schyns P} } @Poster{ RedcayDPKMWGS2010, title = {Do you see what I see? The neural bases of joint attention during a live interactive game}, journal = {Journal of Cognitive Neuroscience}, year = {2010}, month = {4}, volume = {22}, number = {Supplement}, pages = {71}, abstract = {Joint attention refers to the ability to coordinate one’s own attention with another on a third entity (e.g. object or common goal). This uniquely human ability emerges late in the first year of life and is critical to social-cognitive and language development; yet the neural bases for this pivotal skill remain largely understudied. Joint attention includes both Responding to Joint Attention (RJA), or following another’s bid for shared attention on an object, and Initiating Joint Attention (IJA), or initiating a bid for shared attention on an object. To identify the neural bases of both IJA and RJA we implemented a dual-video set-up in which both subject and experimenter could monitor each other via video feed in real-time during fMRI data collection. In each trial, participants either followed the experimenter’s gaze to a target (RJA) or cued the experimenter to look at the target (IJA). A control condition, non-joint attention (NJA), was included in which the subject shifted gaze to a target while the experimenter closed her eyes. Greater activation was seen in the dorsal medial prefrontal cortex (dMPFC) and bilateral posterior superior temporal sulcus (pSTS) during joint attention (IJA + RJA) as compared to NJA. RJA elicited greater activation in posterior superior temporal sulcus (pSTS) than NJA while IJA recruited greater activation in dMPFC than NJA. This novel experimental set-up allowed for the first time identification of the neural bases of both initiating and responding to joint attention.}, web_url = {http://cogneurosociety.org/annual-meeting/previous-meetings/CNS2010_Program.pdf/view}, event_name = {17th Annual Meeting of the Cognitive Neuroscience Society (CNS 2010)}, event_place = {Montréal, Canada}, state = {published}, author = {Redcay E, Dodell-Feder D, Pearrow MJ, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}, Mavros PL, Wang J, Gabrieli JDE and Saxe R} } @Poster{ 6425, title = {Asymmetrien und die Konstruktion von Überblickswissen}, journal = {Experimentelle Psychologie}, year = {2010}, month = {3}, volume = {52}, pages = {16}, web_url = {https://www.teap.de/index.php/teap2010/saarbruecken2010}, event_name = {52. Tagung Experimentell Arbeitender Psychologen (TeaP 2010)}, event_place = {Saarbrücken, Germany}, state = {published}, author = {Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Souman JL{souman}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6241, title = {The Virtual Face Mirror Project: Revealing Dynamic Self-Perception in Humans}, year = {2010}, month = {1}, volume = {4}, number = {137}, file_url = {fileadmin/user_upload/files/publications/CogSys-2010-0137.pdf}, web_url = {http://cogsys2010.ethz.ch/}, event_name = {4th International Conference on Cognitive Systems (CogSys 2010)}, event_place = {Zürich, Switzerland}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}, Kleiner M{kleinerm}{Department Human Perception, Cognition and Action}, Breidt M{mbreidt}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6244, title = {Towards robust scene analysis: A versatile mid-level feature framework}, year = {2010}, month = {1}, volume = {4}, number = {74}, abstract = {We present a novel set of shape-centered interest points. The interest points are formed at locations of high local symmetry. Our symmetry detection is based on Gradient Vector Flow (GVF) [1] fields which provide a high level of stability against noise. The shape centered interest points allow for a robust scale and orientation estimation. We have shown their usefulness for image encoding and superpixel segmentation and demonstrat that they carry information that is to a certain degree complementary to corner based interest points.}, file_url = {/fileadmin/user_upload/files/publications/CogSys%202010%20Poster_[0].pdf}, web_url = {http://www.cogsys2010.ethz.ch/proceedings.html}, event_name = {4th International Conference on Cognitive Systems (CogSys 2010)}, event_place = {Zürich, Switzerland}, state = {published}, author = {Engel D{engel}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Thesis{ 6821, title = {PETaLS: Perception of Emotions in Text - a Linguistic Simulation}, year = {2010}, month = {10}, abstract = {This thesis explores automatic sentiment analysis techniques with the overall goal of simulating human emotional perception of text. To approach this goal we collect an appropriately sized corpus of Grimm’s fairy tale texts, annotated for a rich set of emotional categories. We employ a full range of existing natural language processing tools for the German language on the collected texts in order to extract a large set of features. Finally, we apply two well-known machine learning algorithms (k-NN and Winnow) to perform various classification tasks on linguistic units as small as short phrases. The results we report are based not only on the pure automatic classification accuracies but also on human evaluation of resulting, machine generated, annotations. One distinctive feature of our approach is its maximal automatization. In order to bring in, analyze and automatically annotate a new text, no manual work is required. As such, we view this work as the first step towards the development of a more complex se ntiment analysis system, which aims to simulate the actual human emotional perception of text.}, state = {published}, type = {Diplom}, author = {Volkova EP{evolk}{Department Human Perception, Cognition and Action}} } @Thesis{ Neth2010, title = {The effect of walking speed and avatars on Redirected Walking}, year = {2010}, month = {8}, file_url = {fileadmin/user_upload/files/publications/2011/Master-Thesis-Neth-2010.pdf}, state = {published}, type = {Master}, author = {Neth C{neth}{Department Human Perception, Cognition and Action}} } @Thesis{ 6710, title = {Wide Field of View Head Mounted Display: Integration and Evaluation in a Motion Simulator}, year = {2010}, month = {6}, day = {1}, abstract = {Head Mounted Displays (HMDs) are a flexible and small-sized alternative to projection screens as a visualization device on motion simulators. However, only few HMDs on the market feature a wide field of view (FoV) combined with a low weight. Among these, the xSight 6123 HMD from Sensics, with a horizontal FoV of 118 degrees and a weight of 400g, is a particularly suitable choice for use on a motion simulator. In this work, we integrated the xSight 6123 HMD into the virtual reality setup of our CyberMotion simulator. Therefore, we developed a new camera class for visual systems with stereo capabilities for the open source 3D engine OGRE. Furthermore, we investigated the benefit of the HMD compared to a projection screen by designing and conducting experiments on flight control tasks and driving simulation. We found that subjects show a better control performance when a screen is used, and that a narrow FoV does not affect their performance. Therefore, we conclude that on motion simulators, whenever possible, a projection system should be preferred to an HMD.}, file_url = {/fileadmin/user_upload/files/publications/DA_Volker-Grabe_[0].pdf}, state = {published}, type = {Diplom}, author = {Grabe V{vgrabe}{Department Human Perception, Cognition and Action}} } @Thesis{ Schillinger2010, title = {Whole-brain fMRI using repetition suppression between action and perception reveals cortical areas with mirror neuron properties}, year = {2010}, month = {6}, file_url = {fileadmin/user_upload/files/publications/Diplomarbeit-Schillinger.pdf}, state = {published}, type = {Diplom}, author = {Schillinger F{frieder}{Department Human Perception, Cognition and Action}} } @Miscellaneous{ 6761, title = {Interview über das SUPRA EU Projekt}, journal = {Campus Intern}, year = {2010}, month = {8}, volume = {2010}, number = {2}, pages = {16-17}, state = {published}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action} and Bertenbreiter S} } @Conference{ RobuffoGiordano2010, title = {An Introduction to Passivity and Port-Hamiltonian Systems}, year = {2010}, month = {12}, day = {28}, event_name = {Dipartimento di Informatica e Sistemistica, Università di Roma "La Sapienza"}, event_place = {Roma, Italy}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2010, title = {Bilateral Teleoperation of Multiple UAVs}, year = {2010}, month = {12}, event_name = {Dipartimento di Informatica e Sistemistica, Università di Roma "La Sapienza"}, event_place = {Roma, Italy}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2010_2, title = {Haptic Teleoperation of Multi-Robot Systems}, year = {2010}, month = {12}, event_name = {School of Electrical and Computer Engineering, Georgia Institute of Technology}, event_place = {Atlanta, GA, USA}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ DiLuca2010_2, title = {Recalibration of audiovisual simultaneity}, year = {2010}, month = {11}, day = {10}, event_name = {Colloquium of the Faculteit der Bewegingswetens, Vrije Universiteit, Amsterdam}, event_place = {Amsterdam, Netherlands}, state = {published}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}} } @Conference{ DiLuca2010, title = {Temporal recalibration induced by exposure to asynchronous audiovisual stimuli}, year = {2010}, month = {11}, day = {4}, event_name = {Colloquium of the Department of Cognitive and Biological Sciences, Eberhard-Karls-Universität}, event_place = {Tübingen, Germany}, state = {published}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}} } @Conference{ 6843, title = {Augmented Human-Machine Interface: Providing a Novel Haptic Cueing to the Tele-Operator}, year = {2010}, month = {10}, day = {28}, abstract = {The sense of telepresence is very important in teleoperation environments in which the operator is physically separated from the vehicle. Extending the visual interface to a multi-sensory interface could allow the teleoperator to better perceive information of the environment and its constraints. The use of force feedback would complement the visual information through the sense of touch. This paper focuses on a novel concept of haptic cueing developed in order to optimize the performance of a teleoperator and to improve the human-machine interfaces. A first experiment showed the effectiveness of the newly developed haptic cueing, the Indirect Haptic Aiding, with respect to visual cueing only. In a second experiment, we compared the IHA to an existing haptic concept, the Direct Haptic Aiding. The problem of wind gust rejection in Remotely Piloted Vehicles is used as test bench. The results show the effectiveness of both methods but a better performance of the IHA-based system for pilots without any previous t raining about the haptic aids. DHA-based system provided instead better results after some pilot training on the experiment. Pilots reported better sensation of the wind gusts with IHA-based feedback. The two haptic aids concepts are going to be compared in an obstacle detection/avoidance task.}, web_url = {http://hfr2010.wordpress.com/2010/07/06/program/}, event_name = {3rd Workshop for Young Researchers on Human-Friendly Robotics (HFR 2010)}, event_place = {Tübingen, Germany}, state = {published}, author = {Alaimo SMC{alaimo}{Department Human Perception, Cognition and Action}} } @Conference{ 6998, title = {Communication in Virtual Environments}, year = {2010}, month = {10}, day = {1}, web_url = {http://www.interaction-design.org/references/conferences/proceedings_of_the_joint_virtual_reality_conference_of_egve_-_eurovr_-_vec.html}, event_name = {2010 Joint Virtual Reality Conference of EuroVR - EGVE - VEC (JVRC 2010)}, event_place = {Stuttgart, Germany}, state = {published}, author = {Dodds TJ{dodds}{Department Human Perception, Cognition and Action}} } @Conference{ 7085, title = {Are we explaining consciousness yet?: A philosophical and empirical consideration of the central theories of consciousness}, year = {2010}, month = {10}, volume = {11}, pages = {17}, abstract = {Vegetative state (VS) patients are awake but are not aware of themselves or their environment. By definition they lack the capability of thinking and having sensations of any kind. Given that VS patients are awake and have reflexes that are difficult to dissociate from voluntary actions e.g. crying, smiling, moving extremities, it is a challenge for physicians and neuroscientists to determine the degree of awareness of these patients. Hence, the main difficulty that pose disorders of consciousness such as VS, is whether it is possible to define a state of neural activity that needs to be reached by a person in order to be considered as (un)conscious? Studies on this topic have shown that establishing an objective neuroscientific definition of a conscious mental state is not as easy as people commonly think. How should we then approach the problem of consciousness? This talk aims to highlight the limitations and possibilities that we have when approaching the problem of consciousness with empirical methods and to expose which difficulties can be theoretically overcome so as the reasons why others resist to be elucidated. Specifically the hard and easy problems of consciousness and the problem of the subjective character of consciousness will be described. Afterwards, two leading theories of consciousness and the way they deal with enigmatic experimental results will be presented. Finally, the general discussion will suggest that we currently don't have the adequate sets of concepts required to understand how a physical objective event can give rise to the subjective experience of consciousness.}, web_url = {http://www.neuroschool-tuebingen-nena.de/fileadmin/user_upload/Dokumente/neuroscience/AbstractbookNeNa2010u.pdf}, event_name = {11th Conference of Junior Neuroscientists of Tübingen (NeNa 2010)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Fernandez Cruz AL{anafer}{Department Human Perception, Cognition and Action}} } @Conference{ KaulardWdB2010, title = {Cognitive categories of emotional and conversational facial expressions are influenced by dynamic information}, year = {2010}, month = {10}, volume = {11}, pages = {16}, abstract = {Most research on facial expressions focuses on static, ’emotional’ expressions. Facial expressions, however, are also important in interpersonal communication (’conversational’ expressions). In addition, communication is a highly dynamic phenomenon and previous evidence suggests that dynamic presentation of stimuli facilitates recognition. Hence, we examined the categorization of emotional and conversational expressions using both static and dynamic stimuli. In a between-subject design, 40 participants were asked to group 55 different facial expressions (either static or dynamic) of ten actors in a free categorization task. Expressions were to be grouped according to their overall similarity. The resulting confusion matrix was used to determine the consistency with which facial expressions were categorized. In the static condition, emotional expressions were grouped as separate categories while participants confused conversational expressions. In the dynamic condition, participants uniquely categorized basic and sub-ordinate emotional, as well as several conversational facial expressions. Furthermore, a multidimensional scaling analysis suggests that the same potency and valence dimensions underlie the categorization of both static and dynamic expressions. Basic emotional expressions represent the most effective categories when only static information is available. Importantly, however, our results show that dynamic information allows for a much more fine-grained categorization and is essential in disentangling conversational expressions.}, web_url = {http://www.neuroschool-tuebingen-nena.de/fileadmin/user_upload/Dokumente/neuroscience/AbstractbookNeNa2010u.pdf}, event_name = {11th Conference of Junior Neuroscientists of Tübingen (NeNa 2010)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Kaulard K{kascot}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 7079, title = {Perceptual decisions speed up reflexive saccades}, year = {2010}, month = {10}, volume = {11}, pages = {6}, abstract = {Reflexive saccades are fast eye movements that follow the sudden appearance of a salient visual stimulus in the visual field. This reflexive orienting mechanism could have evolved to enable quick evaluations of sudden changes in the environment and, in doing so, support potentially vital actions (e.g., flight). In light of this, it is surprising that reflexive saccades have mostly been studied with tasks that do not require the saccade to support a perceptual judgment. In the current study we measured properties of reflexive saccades in two conditions: In one condition, the saccade enabled the performance of an object discrimination task (discrimination), in the other, it did not (fixation). In the discrimination task, participants made reflexive saccades following the sudden onsets of Landolt squares (0.1 deg. visual angle) and decided if these squares had an opening at the top or bottom. In the fixation task, the same squares were presented but without an opening. Here participants were instructed to fixate the squares as quickly as possible. The results show that saccades supporting a discrimination task are faster and are initiated earlier than saccades that do not enable the completion of such a task. This demonstrates that reflexive saccades could be influenced by the demands of the task. Possible task-specific factors could include the difficulty of the task, time pressure, or the reward associated with completion of the task.}, web_url = {http://www.neuroschool-tuebingen-nena.de/fileadmin/user_upload/Dokumente/neuroscience/AbstractbookNeNa2010u.pdf}, event_name = {11th Conference of Junior Neuroscientists of Tübingen (NeNa 2010)}, event_place = {Heiligkreuztal, Germany}, state = {published}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2010_3, title = {Towards Bilateral Teleoperation of Multi-Robot Systems}, year = {2010}, month = {10}, web_url = {http://hfr2010.wordpress.com/2010/07/06/program/}, event_name = {3rd Workshop for Young Researchers on Human-Friendly Robotics (HFR 2010)}, event_place = {Tübingen, Germany}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ 6785, title = {Self-Avatars in Immersive Virtual Environments as a Tool to Investigate Embodied Perception}, year = {2010}, month = {9}, day = {30}, web_url = {http://www.bodyrep.ethz.ch/}, event_name = {Body Representation in Physical and Virtual Reality with Application to Rehabilitation}, event_place = {Monte Veritá, Switzerland}, state = {published}, author = {Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Conference{ 6759, title = {Brain and Cognitive Engineering: What can Engineers learn from Cognitive Scientists?}, year = {2010}, month = {9}, day = {28}, abstract = {This presentation will give an overview of current topics in the Biological Cybernetics labs at the Max Planck Institute in Tübingen and the Department of Brain and Cognitive Engineering at Korea University. Recent examples from our research on face and object recognition will highlight the importance of dynamic and multi-sensory information as well as active vision for recognition and show how perceptual research can contribute towards the development of better artificial systems.}, event_name = {Department of Brain and Cognitive Engineering, Korea University}, event_place = {Seoul, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6777, title = {A Comparison of Direct and Indirect Haptic Aiding for Remotely Piloted Vehicles}, year = {2010}, month = {9}, day = {14}, abstract = {The talk presents an experimental evaluation of two different Haptic aiding concepts: Direct and Indirect Haptic Aiding. Two Haptic systems were designed and tested using an experimental setup. The problem of wind gust rejection in Remotely Piloted Vehicles is used as test bench. Test results show the effectiveness of both methods but a better performance of the IHA-based system for pilots without any previous training about the experiment. DHA-based system provided instead better results after some pilot training on the experiment. Pilots reported better sensation of the wind gusts with IHA-based feedback.}, web_url = {http://www.ieee.org/conferences_events/conferences/conferencedetails/index.html?Conf_ID=16167}, event_name = {19th IEEE International Symposium in Robot and Human Interactive Communication (IEEE Ro-Man 2010)}, event_place = {Viareggio, Italy}, state = {published}, author = {Alaimo SMC{alaimo}{Department Human Perception, Cognition and Action}} } @Conference{ 6774, title = {The behavioral hallmarks of face processing in humans and macaques - an eye tracking investigation}, year = {2010}, month = {9}, day = {14}, abstract = {An essential characteristic of primates is social cognition. Social cognition is an evolutionary result of living in social systems. Underlying all of the social abilities are the recognition of kin and conspecifics and the analysis of communicational signals, in which one element is crucial: the face. Thus, given the social significance of faces compared to other natural objects, it may appear obvious that the brain processes faces differently than non-face objects. The question to what extent faces are processed differently when compared to non-face object has been a major focus of research in human for the past several decades. The behavioral hallmarks of face perception (holistic face perception and subordinate-level entry point) as well as the underlying neural mechanisms have been studied extensively in humans. Relatively little is known so far about the behavioral abilities with respect to face perception in the macaque, while the neural signal derived from single cell recordings taught us much about t he aspects of facial selectivity in the brain. Here, critical experimental paradigms, known from the research in humans, were employed in combination with standard eye tracking methods to investigate face processing abilities in macaques and humans. This comparative approach not only demonstrates that macaques and humans employ similar face processing strategies, it also illustrates an effective approach on comparative cognitive research questions.}, web_url = {http://primate-society.com/ips/}, event_name = {International Primatological Society XXIII Congress (IPS 2010)}, event_place = {Kyoto, Japan}, state = {published}, author = {Dahl CD{dahl}{Department Human Perception, Cognition and Action}{Department Physiology of Cognitive Processes}} } @Conference{ 6733, title = {Towards artificial systems: what can we learn from human perception}, year = {2010}, month = {9}, day = {13}, number = {Lecture 1442}, event_name = {Asia Pacific Center for Theoretical Physics (APCTP) Headquarters}, event_place = {Pohang, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Pretto2011, title = {Influence of display type on drivers’ performance in a motion based driving simulator}, year = {2010}, month = {9}, day = {9}, web_url = {http://dsc2010.ensam.eu/symposia/browse/DSC2012/100/en}, event_name = {Driving Simulation Conference Europe (DSC 2010)}, event_place = {Paris, France}, state = {published}, author = {Pretto P{pretto}{Department Human Perception, Cognition and Action}} } @Conference{ 6756, title = {Towards Artificial Systems: What can we learn from human perception?}, year = {2010}, month = {9}, day = {9}, event_name = {Seoul National University, School of Computer Science and Engineering}, event_place = {Seoul, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6757, title = {The Cybernetics Approach to Cognitive Engineering}, year = {2010}, month = {9}, day = {8}, event_name = {Distinguished Lecture Series, Korea University}, event_place = {Seoul, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6633, title = {Towards artificial systems: what can we learn from human perception}, year = {2010}, month = {8}, day = {30}, web_url = {http://sejong.knu.ac.kr/PRICAI2010/}, event_name = {11th Pacific Rim International Conference on Artificial Intelligence (PRICAI 2010)}, event_place = {Daegu, South Korea}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6740, title = {Cognitive categories of emotional and conversational facial expressions are influenced by dynamic information}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {157}, abstract = {Most research on facial expressions focuses on static, ‘emotional’ expressions. Facial expressions, however, are also important in interpersonal communication (‘conversational’ expressions). In addition, communication is a highly dynamic phenomenon and previous evidence suggests that dynamic presentation of stimuli facilitates recognition. Hence, we examined the categorization of emotional and conversational expressions using both static and dynamic stimuli. In a between-subject design, 40 participants were asked to group 55 di erent facial expressions (either static or dynamic) of ten actors in a free categorization task. Expressions were to be grouped according to their overall similarity. The resulting confusion matrix was used to determine the consistency with which facial expressions were categorized. In the static condition, emotional expressions were grouped as separate categories while participants confused conversational expressions. In the dynamic condition, participants uniquely categorized basic and sub-ordinate emotional, as well as several conversational facial expressions. Furthermore, a multidimensional scaling analysis suggests that the same potency and valence dimensions underlie the categorization of both static and dynamic expressions. Basic emotional expressions represent the most e ective categories when only static information is available. Importantly, however, our results show that dynamic information allows for a much more fine-grained categorization and is essential in disentangling conversational expressions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100478}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Kaulard K{kascot}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6726, title = {Faces are represented relative to race-specific norms}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {155}, abstract = {Recent models of face perception often adopt a framework in which faces are represented as points in a multidimensional space, relative to the average face that serves as a norm. Faces share many visual properties and could be encoded in one face space against one single norm. However, certain face properties may result in grouping of similar faces. How faces might be ‘subclassified’ in face space remains thus to be determined. We studied the processing of faces of different races, using high-level aftereffects, where exposure to one face systematically distorts the perception of a subsequently viewed face towards the ‘opposite’ identity in face space. We measured identity aftereffects for adapt-test pairs that were opposite race-specific (Asian and Caucasian) averages and pairs that were opposite a ‘generic’ average (both races morphed together). Aftereffects were larger for race-specific than for generic anti-faces. Since adapt-test pairs that lie opposite each other in face space generate larger aftereffects than non-opposite test pairs, these results suggest that Asian and Caucasian faces are coded using race-specific norms. Moreover, identification (at low identity strength) of the target faces was easier around the race-specific norms than around the generic norm, indicating that norms also have a functional role in face processing.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100426}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Armann RGM{armann}{Department Human Perception, Cognition and Action}, Jeffery L, Calder AJ, B\"ulthoff I{isa}{Department Human Perception, Cognition and Action} and Rhodes G} } @Conference{ 6725, title = {Optimizing minimal sketches of visual object categories}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {11}, abstract = {We present an iterative optimization scheme for obtaining minimal line sketches of object categories. Minimal sketches are introduced as a tool to derive the most important visual properties of a visual object category and can potentially provide useful constraints for automatic classification algorithms. We define the minimal sketch of an object category as the minimal number of straight lines necessary to lead to a correct recognition by 75% of naïve participants after one second of presentation. Nine participants produced sketches of 30 object categories. We displayed the three sketches with the lowest number of lines for each category to 24 participants who freely named them. In consecutive rounds the sketchers had to optimize their drawings independently based on sketches and responses of the previous rounds. The optimized sketches were subsequently rated again by 24 new subjects. The average number of lines used in the sketches decreased from 8.8 to 7.9 between the two trials while the average recognition rate increased from 57.3% to 67.9%. 27 of the 30 categories had at least one sketch that was recognized by more than 75% of subjects. For most of the categories, the sketches converged to an optimum within two drawing-rating rounds.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100475}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Engel D{engel}{Department Human Perception, Cognition and Action}, Kottler VA, Malisi CU, R\"ottig M, Schultheiss SJ, Willing EM, Curio C{curio}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6405, title = {Perceived object stability is affected by the internal representation of gravity}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {109}, abstract = {Knowing an object's physical stability affects our expectations about its behaviour and our interactions with it. Objects topple over when the gravity-projected centre-of-mass (COM) lies outside the support area. The critical angle (CA) is the orientation for which an object is perceived to be equally likely to topple over or right itself, which is influenced by global shape information about an object's COM and its orientation relative to gravity. When observers lie on their sides, the perceived direction of gravity is tilted towards the body. Here we test the hypothesis that the CA of falling objects is affected by this internal representation of gravity. Observers sat upright or lay left- or right-side-down, and observed images of objects with different 3D mass distributions that were placed close to the right edge of a table in various orientations. Observers indicated whether the objects were more likely to fall back onto or off the table. The subjective visual vertical was also tested as a measure of perceived gravity. Our results show the CA increases when lying right-side-down and decreases when left-side-down relative to an upright posture, consistent with estimating the stability of rightward falling objects as relative to perceived and not physical gravity.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100540}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {Fleming RW{roland}{Department Human Perception, Cognition and Action}, Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ delaRosaCB2010, title = {Social interaction recognition and object recognition have different entry levels}, journal = {Perception}, year = {2010}, month = {8}, volume = {39}, number = {ECVP Abstract Supplement}, pages = {12}, abstract = {Objects can be recognized at different levels of abstraction, eg basic-level (eg flower) and subordinate level (eg rose). The entry level refers to the abstraction level for which object recognition is fastest. For objects, this is typically the basic-level. Is the basic-level also the entry level for the social interaction recognition? We compared basic-level and subordinate recognition of objects and social interactions. Because social interaction abstraction levels are unknown, Experiment 1 determined basic-level and subordinate categories of objects and social interactions in a free grouping and naming experiment. We verified the adequacy of our method to identify abstraction levels by replicating previously reported object abstraction levels. Experiment 2 used the object and social interaction abstraction levels of Experiment 1 to examine the entry levels for social interaction and object recognition by means of recognition speed. Recognition speed was measured (reaction times, accuracy) for each combination of stimulus type and abstraction level separately. Subordinate recognition of social interactions was significantly faster than basic-level recognition while the results were reversed for objects. Because entry levels are associated with faster recognition, the results indicate different entry levels for object and social interaction recognition, namely the basic-level for objects and possibly the subordinate level for social interactions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v100486}, event_name = {33rd European Conference on Visual Perception}, event_place = {Lausanne, Switzerland}, state = {published}, author = {de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Choudhery R{choudhery}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ Mohler2010, title = {Self-Avatars in Immersive Virtual Environments as a Tool to investigate Embodied Perception}, year = {2010}, month = {7}, day = {19}, abstract = {A rendering of a representation of one's own body in a head mounted display (HMD) virtual environment (VE) is a useful tool for investigating embodied perception. Currently, few HMD VE systems display a rendering of the users own body. Subjectively, this often leads to a sense of disembodiment in the VE. In a recent study, we found that the experience with an avatar changed the typical pattern of distance underestimation seen in many HMD studies. Users showed an increase in distance estimations with avatar experience, especially when the avatar was animated in correspondence with their own body-movements. Additionally, we investigated the impact of experience with an animated avatar on other common tasks within a HMD VE (locomotion, object interaction and social interaction). We found that pre-exposure to an animated avatar had no significant effect on these behaviors. Most recently we investigated the impact of self-avatars on the ability of multi-users in a HMD VE to communicate. We found that, especially when in 3rd person perspective, the animation of the avatars increased the rate of communication. We believe that immersive VEs provide great potential to further investigate embodied perception.}, web_url = {http://wwwmath.uni-muenster.de/HotNews/show_artikel.php?id=2433&brettid=47}, event_name = {Westfälische Wilhelms-Universität: Fachbereich 10 Mathematik und Informatik}, event_place = {Münster, Germany}, state = {published}, author = {Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Conference{ 6681, title = {Multisensory responses in temporal association cortex}, year = {2010}, month = {7}, day = {1}, event_name = {Karolinska Institute, Department of Neuroscience}, event_place = {Stockholm, Sweden}, state = {published}, author = {Dahl CD{dahl}{Department Human Perception, Cognition and Action}{Department Physiology of Cognitive Processes}} } @Conference{ 6667, title = {Self-Avatars in Immersive Virtual Environments as a Tool to investigate Embodied Perception}, year = {2010}, month = {6}, day = {18}, abstract = {A rendering of a representation of one‘s own body in a head mounted display (HMD) virtual environment (VE) is a useful tool for investigating embodied perception. Currently, few HMD VE systems display a rendering of the users own body. Subjectively, this often leads to a sense of disembodiment in the VE. In a recent study, we found that the experience with an avatar changed the typical pattern of distance underestimation seen in many HMD studies. Users showed an increase in distance estimations with avatar experience, especially when the avatar was animated in correspondence with their own body-movements. Additionally, we investigated the impact of experience with an animated avatar on other common tasks within a HMD VE (locomotion, object interaction and social interaction). We found that pre-exposure to an animated avatar had no significant effect on these behaviors. Most recently we investigated the impact of self-avatars on the ability of multi-users in a HMD VE to communicate. We found that, especially when in 3rd person perspective, the animation of the avatars increased the rate of communication. We believe that immersive VEs provide great potential to further investigate embodied perception.}, web_url = {http://www.eventlab-ub.org/index.php?menu=events&FP=p&P=3}, event_name = {Event Lab: Universitat de Barcelona}, event_place = {Barcelona, Spain}, state = {published}, author = {Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Conference{ 6640, title = {The MPI CyberMotion Simulator: A new concept for ab initio helicopter flight training}, year = {2010}, month = {6}, day = {18}, event_name = {Institut für Hirnforschung, Bremen University}, event_place = {Bremen, Germany}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6680, title = {The MPI CyberMotion Simulator: Development of a novel helicopter trainer}, year = {2010}, month = {6}, day = {11}, event_name = {ILA Helikopter Forum}, event_place = {Berlin, Germany}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6578, title = {Visual-haptic perception of compliant materials}, year = {2010}, month = {6}, day = {3}, web_url = {http://www.allpsych.uni-giessen.de/for560/panda/index.html}, event_name = {Workshop "Perception and Action"}, event_place = {Schloss Rauischholzhausen, Germany}, state = {published}, author = {Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}} } @Conference{ Bulthoff2010, title = {Die Wechselwirkung von Identität und Geschlecht bei der Gesichtswahrnehmung}, year = {2010}, month = {6}, pages = {16}, abstract = {Wir untersuchten die Wechselwirkung von identittäts- und geschlechtsspezifi schen Informationen in der Gesichtswahrnehmung. In Experiment 1 war es die Aufgabe der Probanden, die Originalversion eines bekannten Gesichts neben einer Anzahl modi zierter Versionen dieses Gesichts auszuwählen. Diese Aufgabe war leichter, wenn das Originalgesicht zusammen mit identitätsmodi zierten statt mit geschlechtsmodi zierten Versionen des Originalgesichts präsentiert wurde, was den Schluss nahelegt, dass geschlechtsspezi sche Informationen nicht akkurat im Gedächtnis abgelegt werden. In Experiment 2, modi zierten wir das Geschlecht einer Reihe von Gesichtern, indem wir weibliche Gesichter in männliche Gesichter transformierten. Probanden hatten grössere Schwierigkeiten, diese geschlechtsmodifi zierten Gesichter als männliche Gesichter zu klassi zieren, wenn ihnen das Originalgesicht bekannt war. Im Gegensatz zum klassischen Modell der Gesichtsverarbeitung nach Bruce & Young (1986), weisen unsere Daten darauf hin, dass bei Gesichtern geschlechtspezifi sche Informationen nicht unabhängig von identitätsspezi schen Informationen verarbeitet werden. Zusammenfassend können wir sagen, dass unser visuelles System nicht unbedingt darauf angelegt zu sein scheint, perfekte Modelle auch bekannter Gesichter zu speichern { besonders nicht im Hinblick auf das Geschlecht. Vermutlich ist eine akkurate Geschlechtsinformation nicht notwendig - vor allem da sie nur aus den beiden Klassen männlich und weiblich besteht - so dass identitätsspezfii sche Informationen geschlechtsspezi sche Informationen dominieren, auch wenn dies nicht zweckmässig ist.}, web_url = {http://tagung.dgpa.de/fileadmin/files/ABSTRACTBAND_web.pdf}, event_name = {36. Tagung "Psychologie und Gehirn"}, event_place = {Greifswald, Germany}, state = {published}, author = {B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Conference{ Volkova2010, title = {Emotional Perception of Fairy Tales: Achieving Agreement in Emotion Annotation of Text}, year = {2010}, month = {6}, abstract = {Emotion analysis (EA) is a rapidly developing area in computational linguis- tics. An EA system can be extremely useful in fields such as information retrieval and emotion-driven computer animation. For most EA systems, the number of emotion classes is very limited and the text units the classes are assigned to are discrete and predefined. The question we address is whether the set of emotion categories can be enriched and whether the units to which the categories are as- signed can be more flexibly defined. Ten German native speakers voluntarily participated in the series of experiments we conducted to find answers to these issues. The participants were di- vided into two groups and each participant worked on five of the eight Grimms fairy tales; each text was 1200-1400 words long and written in Standard German. Fifteen emotions categories were used - seven positive: relief, joy, hope, interest, compassion, surprise, approval; seven negative: disturbance, sadness, despair, disgust, hatred, fear, anger; and neutral. The main task for the participants was to locate and mark stretches of text where an emotion was to be conveyed through the speech melody and/or facial expressions if the participant was to read the text out loud. Another task was to annotate the word lists for the fairy tale texts. Other assignments included cognitive task on emotion categories taken outside the fairy tales context, e.g. giving definitions to emotion categories or organizing the categories into clusters. The κ of inter-annotator agreement (IAA) scores were calculated using the emotion clusters information, for according to the results, participants would of- ten stably use different emotions from same clusters at the same stretch of text. Four out of ten participants, two from each group, had very low IAA scores, a high proportion of unmarked text, and they used few emotion categories, so for the evaluation part their data was discarded. The final IAA evaluation was calcu- lated on all the annotation pairs obtained from the six remaining participants. The total number of annotation pairs thus amounted to 48: two texts annotated by all the six annotators, six texts annotated by three annotators for each of the two annotation sets. The annotator agreement was moderate on average (0.53), and some pairs approached the almost perfect IAA rate (0.83). The IAA rates, calculated on the full set of fifteen emotions, without taking the emotion clusters into consideration, gave a moderate IAA rate on average (0.34) and reached substantial level (0.62) at maximum. We consider the resulting IAA rates to be high enough to accept the anno- tations as suitable for gold-standard corpus compilation in the frame of this re- search. As such, we view this work as the first step towards the development of a more complex EA system, which aims to simulate the actual human emotional perception of text. The final goal of our project is an EA system used for emotion enhancement of human-computer interaction in virtual or augmented reality. It is meant to be a bridge between unprocessed input text and visual and auditory information, coming from a virtual character in story telling scenarios.}, event_name = {20. Tagung der Computerlinguistik Studierenden (TaCoS 2010)}, event_place = {Zürich, Switzerland}, state = {published}, author = {Volkova EP{evolk}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2010_4, title = {Decentralized Methods for Cooperative Task Execution in Multi-robot Systems}, year = {2010}, month = {5}, event_name = {GRASP Laboratory, University of Pennsylvania}, event_place = {Philadelphia, PA, USA}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Conference{ 6407, title = {Shape from shading and object stability seen from a different perspective}, year = {2010}, month = {5}, event_name = {Centre for Vision Research, York University}, event_place = {Toronto, Canada}, state = {published}, author = {Barnett-Cowan M{mbc}{Department Human Perception, Cognition and Action}} } @Conference{ 6432, title = {The hallmarks of face perception in humans and monkeys}, year = {2010}, month = {4}, day = {12}, event_name = {Eötvös Lorand University, Department of Ethology}, event_place = {Budapest, Hungary}, state = {published}, author = {Dahl CD{dahl}{Department Human Perception, Cognition and Action}{Department Physiology of Cognitive Processes}} } @Conference{ 6539, title = {Human-Machine Interfaces for VR and Real World Applications}, year = {2010}, month = {4}, event_name = {Eidgenössische Technische Hochschule Zürich}, event_place = {Zürich, Switzerland}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ 6446, title = {Die Welt in unseren Köpfen: Sehen und Erkennen in Natur und Technik}, year = {2010}, month = {3}, day = {25}, abstract = {Die Überlegenheit der natürlichen über die künstliche Intelligenz liegt in der Fähigkeit des menschlichen Gehirns, die verschiedenen Sinnesinformationen miteinander zu verrechnen um dadurch sinnvolle Handlungen zu ermöglichen. Um diese Leistungen unseres Gehirns zu verstehen und in technische Systeme umzusetzen bedarf es der vereinten Anstrengungen verschiedener Disziplinen, darunter Biologie, Informatik, Mathematik, Physik, Psychologie und Robotik. Die neuen Methoden der Virtuellen Realität erlauben in Verhaltensexperimenten einen sensorischen Realismus zu erzeugen, der der Erfahrung der realen Welt weitgehend entspricht. Gleichzeitig erlauben diese Methoden eine genaue Kontrolle der Reizparameter, die für eine psychophysische Untersuchung notwendig sind. Darüber hinaus werden Wahrnehmungsleistungen nicht isoliert betrachtet sondern im geschlossenen Regelkreis von Wahrnehmung und Handlung untersucht.}, event_name = {Health and Life Sciences, Private Universität im Fürstentum Liechtenstein}, event_place = {Triesen, Liechtenstein}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6605, title = {Interactive Perceptual Graphics for Brain Engineering}, year = {2010}, month = {3}, day = {13}, event_name = {HiGraphics}, event_place = {Hirschegg, Austria}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}} } @Conference{ 6371, title = {Realtime Facial Animation for Studying Interactive Perception and Rehabilitation}, year = {2010}, month = {2}, day = {21}, web_url = {http://www.cin.uni-tuebingen.de/fileadmin/pdfs/Events/Broschuere_fin-1_Giese.pdf}, event_name = {Neural Encoding of Perception and Action, Max Planck Guest House}, event_place = {Tübingen, Germany}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}} } @Conference{ 6343, title = {The Cybernetics Approach to Perception, Cognition and Action}, year = {2010}, month = {1}, day = {29}, abstract = {The question of how we perceive and interact with the world around us has been at the heart of cognitive and neuroscience research for the last decades. Despite tremendous advances in the field of computational vision – made possible by the development of powerful learning techniques as well as the existence of large amounts of labeled training data for harvesting - artificial systems have yet to reach human performance levels and generalization capabilities. In this contribution we want to highlight some recent results from perceptual studies that could help to bring artificial systems a few steps closer to this grand goal. In particular, we focus on the issue of spatio-temporal object representations (dynamic faces), face synthesis, as well as the need for taking into account multi-sensory data in models of object categorization. In all of these perceptual research lines, the underlying research philosophy was to combine the latest tools in computer vision, computer graphics, and computer simulations in or der to gain a deeper understanding of recognition and categorization in the human brain. Conversely, we discuss how the perceptual results can feed back into the design of better and more efficient tools for artificial systems.}, web_url = {https://cast.switch.ch/vod/clips/262ah0ec3q/flash.html}, event_name = {2nd European Network for the Advancement of Artificial Cognitive Systems, Interaction and Robotics}, event_place = {Zürich, Switzerland}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6274, title = {Towards a New Generation of Multisensory Human-Machine Interfaces for VR and Real-World Applications}, year = {2010}, month = {1}, day = {26}, web_url = {http://www.ist.uni-stuttgart.de/news/seminars/kolloquium/content/2010_01_26.shtml}, event_name = {Kolloquium Technische Kybernetik, Institut für Systemtheorie und Regelungstechnik}, event_place = {Stuttgart, Germany}, state = {published}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}} } @Conference{ 6264, title = {Towards artificial systems: what can we learn from human perception?}, year = {2010}, month = {1}, day = {18}, event_name = {45th Winter Seminar 2010}, event_place = {Klosters, Switzerland}, state = {published}, author = {B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Conference{ 6259, title = {Realtime facial expression simulation towards a cognitive model of interaction}, year = {2010}, month = {1}, day = {15}, web_url = {http://www.ruhr-uni-bochum.de/philosophy/emotion/Symposium.html}, event_name = {Self and Others in Mind: Interdisciplinary Viewpoints on Self-Construals}, event_place = {Berlin, Germany}, state = {published}, author = {Curio C{curio}{Department Human Perception, Cognition and Action}} } @Conference{ Franchi2010_5, title = {Decentralized strategies for multi-robot systems: from autonomous behavior to multimodal human interaction}, year = {2010}, month = {1}, event_name = {Max Planck Institute for Biological Cybernetics}, event_place = {Tübingen, Germany}, state = {published}, author = {Franchi A{antonio}{Department Human Perception, Cognition and Action}} } @Article{ 5915, title = {Dynamic information for the recognition of conversational expressions}, journal = {Journal of Vision}, year = {2009}, month = {12}, volume = {9}, number = {13:7}, pages = {1-17}, abstract = {Communication is critical for normal, everyday life. During a conversation, information is conveyed in a number of ways, including through body, head, and facial changes. While much research has examined these latter forms of communication, the majority of it has focused on static representations of a few, supposedly universal expressions. Normal conversations, however, contain a very wide variety of expressions and are rarely, if ever, static. Here, we report several experiments that show that expressions that use head, eye, and internal facial motion are recognized more easily and accurately than static versions of those expressions. Moreover, we demonstrate conclusively that this dynamic advantage is due to information that is only available over time, and that the temporal integration window for this information is at least 100 ms long.}, web_url = {http://www.journalofvision.org/9/13/7/Cunningham-2009-jov-9-13-7.pdf}, state = {published}, DOI = {10.1167/9.13.7}, author = {Cunningham DW{dwc}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Article{ 6218, title = {Evaluation of reverse tone mapping through varying exposure conditions}, journal = {ACM Transactions on Graphics}, year = {2009}, month = {12}, volume = {28}, number = {5:160}, pages = {1-8}, abstract = {Most existing image content has low dynamic range (LDR), which necessitates effective methods to display such legacy content on high dynamic range (HDR) devices. Reverse tone mapping operators (rTMOs) aim to take LDR content as input and adjust the contrast intelligently to yield output that recreates the HDR experience. In this paper we show that current rTMO approaches fall short when the input image is not exposed properly. More specifically, we report a series of perceptual experiments using a Brightside HDR display and show that, while existing rTMOs perform well for under-exposed input data, the perceived quality degrades substantially with over-exposure, to the extent that in some cases subjects prefer the LDR originals to images that have been treated with rTMOs. We show that, in these cases, a simple rTMO based on gamma expansion avoids the errors introduced by other methods, and propose a method to automatically set a suitable gamma value for each image, based on the image key and empirical data. We validate the results both by means of perceptual experiments and using a recent image quality metric, and show that this approach enhances visible details without causing artifacts in incorrectly-exposed regions. Additionally, we perform another set of experiments which suggest that spatial artifacts introduced by rTMOs are more disturbing than inaccuracies in the expanded intensities. Together, these findings suggest that when the quality of the input data is unknown, reverse tone mapping should be handled with simple, non-aggressive methods to achieve the desired effect.}, web_url = {http://giga.cps.unizar.es/~diegog/ficheros/pdf_papers/Masia_rTM_sAsia09.pdf}, state = {published}, DOI = {10.1145/1618452.1618506}, author = {Masia B, Agustin S, Fleming RW{roland}{Department Human Perception, Cognition and Action}, Sorkine O and Gutierrez D} } @Article{ 5515, title = {Imagined Self-Motion Differs from Perceived Self-Motion: Evidence from a Novel Continuous Pointing Method}, journal = {PLoS One}, year = {2009}, month = {11}, volume = {4}, number = {11}, pages = {1-11}, abstract = {Background The extent to which actual movements and imagined movements maintain a shared internal representation has been a matter of much scientific debate. Of the studies examining such questions, few have directly compared actual full-body movements to imagined movements through space. Here we used a novel continuous pointing method to a) provide a more detailed characterization of self-motion perception during actual walking and b) compare the pattern of responding during actual walking to that which occurs during imagined walking. Methodology/Principal Findings This continuous pointing method requires participants to view a target and continuously point towards it as they walk, or imagine walking past it along a straight, forward trajectory. By measuring changes in the pointing direction of the arm, we were able to determine participants' perceived/imagined location at each moment during the trajectory and, hence, perceived/imagined self-velocity during the entire movement. The specific pattern of pointing behaviour that was revealed during sighted walking was also observed during blind walking. Specifically, a peak in arm azimuth velocity was observed upon target passage and a strong correlation was observed between arm azimuth velocity and pointing elevation. Importantly, this characteristic pattern of pointing was not consistently observed during imagined self-motion. Conclusions/Significance Overall, the spatial updating processes that occur during actual self-motion were not evidenced during imagined movement. Because of the rich description of self-motion perception afforded by continuous pointing, this method is expected to have significant implications for several research areas, including those related to motor imagery and spatial cognition and to applied fields for which mental practice techniques are common (e.g. rehabilitation and athletics).}, web_url = {http://www.plosone.org/article/fetchObjectAttachment.action;jsessionid=7EC338C2BF98904DAB7CCEA3B5344BA6.ambra02?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0007793&representation=PDF}, state = {published}, DOI = {10.1371/journal.pone.0007793}, EPUB = {e7793}, author = {Campos JL{camposjl}{Department Human Perception, Cognition and Action}, Siegle JH{jsiegle}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Loomis JM{loomis}} } @Article{ 5629, title = {Liquid crystal display response time estimation for medical applications}, journal = {Medical Physics}, year = {2009}, month = {11}, volume = {36}, number = {11}, pages = {4984-4990}, web_url = {http://tannerlab.com/papers/ElzeTanner2009_preprint_medphys.pdf}, state = {published}, DOI = {10.1118/1.3238154}, author = {Elze T and Tanner TG{tanner}{Department Human Perception, Cognition and Action}} } @Article{ 6207, title = {Three-Dimensional Assessment of Facial Development in Children With Pierre Robin Sequence}, journal = {Journal of Craniofacial Surgery}, year = {2009}, month = {11}, volume = {20}, number = {6}, pages = {2055-2060}, abstract = {Newborns with Pierre Robin sequence (PRS) have mandibular hypoplasia, glossoptosis, and possibly cleft palate. Their facial appearance is characteristic. The further facial development is controversial. The aim of this study was to analyze the facial development of children with PRS. In a prospective, cross-sectional study, 344 healthy children and 37 children with PRS and cleft palate younger than 8 years were scanned three-dimensionally. Twenty-one standard anthropometric landmarks were identified, and the images were superimposed. Growth curves for normal facial development were calculated. The facial morphology of children with PRS was compared with that of healthy children. The facial growth of children with PRS in the transversal and vertical direction was normal. In the sagittal direction, the mandibular deficit was confirmed. Except for the orbital landmarks and nasion, all landmarks of the midface demonstrated a significant sagittal deficit. This difference to healthy children remained constant for all ages. Our study cannot support the theory of mandibular catch-up growth. The sagittal deficit of the midface could be observed in all ages. This indicates that children with PRS have a very early, severe, and persistent underdevelopment of this part of the face. We conclude that this disturbance must be addressed in early childhood with orthodontic and speech therapy.}, web_url = {http://journals.lww.com/jcraniofacialsurgery/Abstract/2009/11000/Three_Dimensional_Assessment_of_Facial_Development.21.aspx}, state = {published}, DOI = {10.1097/SCS.0b013e3181be87db}, author = {Krimmel M, Kluba S, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, Bacher M, Dietz K, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Reinert S} } @Article{ 5824, title = {Cross-Modal Transfer in Visual and Haptic Face Recognition}, journal = {IEEE Transactions on Haptics}, year = {2009}, month = {10}, volume = {200}, number = {4}, pages = {236-240}, abstract = {We report four psychophysical experiments investigating cross-modal transfer in visual and haptic face recognition. We found surprisingly good haptic performance and cross-modal transfer for both modalities. Interestingly, transfer was asymmetric depending on which modality was learned first. These findings are discussed in relation to haptic object processing and face processing.}, web_url = {http://www2.computer.org/portal/web/csdl/doi/10.1109/TOH.2009.18}, state = {published}, DOI = {10.1109/TOH.2009.18}, author = {Dopjans L{ldopjans}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 5895, title = {Spatial Organization of Multisensory Responses in Temporal Association Cortex}, journal = {Journal of Neuroscience}, year = {2009}, month = {9}, volume = {29}, number = {38}, pages = {11924-11932}, abstract = {Neurons in sensory cortices are often topographically organized according to their response preferences. We here show that such an organization of response preferences also exists in multisensory association cortex. Using electrophysiological mappings we probed the modality preference to auditory and visual stimuli of neurons in the superior temporal association cortex of non-human primates. We found that neurons preferring the same modality (auditory or visual) often co-occur in close spatial proximity, or occur intermingled with bimodal neurons. Neurons preferring different modalities, in contrast, occur spatially separated. This organization at the scale of individual neurons leads to extended patches of same modality preference when analyzed at the scale of millimeters, revealing larger scale regions that preferentially respond to the same modality. In addition, we find that neurons exhibiting signs of multisensory interactions, such as super- or sub-additive response summation, also occur in spatial clus ters. Together, these results reveal a spatial organization of modality preferences in a higher association cortex, and lend support to the notion that topographical organizations might serve as a general principle of integrating information within and across the sensory modalities.}, file_url = {/fileadmin/user_upload/files/publications/dahl_kayser2009_5895[0].pdf}, web_url = {http://www.jneurosci.org/cgi/reprint/29/38/11924}, state = {published}, DOI = {10.1523/JNEUROSCI.3437-09.2009}, author = {Dahl CD{dahl}{Department Human Perception, Cognition and Action}{Department Physiology of Cognitive Processes}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes} and Kayser C{kayser}{Department Physiology of Cognitive Processes}{Research Group Physiology of Sensory Integration}} } @Article{ 5527, title = {The role of attention on the integration of visual and inertial cues}, journal = {Experimental Brain Research}, year = {2009}, month = {9}, volume = {198}, number = {2-3}, pages = {287-300}, abstract = {The extent to which attending to one stimulus while ignoring another influences the integration of visual and inertial (vestibular, somatosensory, proprioceptive) stimuli is currently unknown. It is also unclear how cue integration is affected by an awareness of cue conflicts. We investigated these questions using a turn-reproduction paradigm, where participants were seated on a motion platform equipped with a projection screen and were asked to actively return a combined visual and inertial whole-body rotation around an earth-vertical axis. By introducing cue conflicts during the active return and asking the participants whether they had noticed a cue conflict, we measured the influence of each cue on the response. We found that the task instruction had a significant effect on cue weighting in the response, with a higher weight assigned to the attended modality, only when participants noticed the cue conflict. This suggests that participants used task-induced attention to reduce the influence of stimuli that conflict with the task instructions.}, web_url = {http://springerlink.metapress.com/content/e672303w0688m17p/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-009-1767-8}, author = {Berger DR{berger}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 5646, title = {Two Routes to Face Perception: Evidence From Psychophysics and Computational Modeling}, journal = {Cognitive Science}, year = {2009}, month = {9}, volume = {33}, number = {8}, pages = {1413-1440}, file_url = {/fileadmin/user_upload/files/publications/SchLobColWal_inPress_[0].pdf}, web_url = {http://www3.interscience.wiley.com/cgi-bin/fulltext/122605602/PDFSTART}, state = {published}, DOI = {10.1111/j.1551-6709.2009.01059.x}, author = {Schwaninger A{aschwan}{Department Human Perception, Cognition and Action}, Lobmaier JS, Wallraven C{walli}{Department Human Perception, Cognition and Action} and Collishaw S} } @Article{ 5741, title = {Categorizing art: Comparing humans and computers}, journal = {Computers and Graphics}, year = {2009}, month = {8}, volume = {33}, number = {4}, pages = {484-495}, abstract = {The categorization of art (paintings, literature) into distinct styles such as Expressionism, or Surrealism has had a profound influence on how art is presented, marketed, analyzed, and historicized. Here, we present results from human and computational experiments with the goal of determining to which degree such categories can be explained by simple, low-level appearance information in the image. Following experimental methods from perceptual psychology on category formation, naive, non-expert participants were first asked to sort printouts of artworks from different art periods into categories. Converting these data into similarity data and running a multi-dimensional scaling (MDS) analysis, we found distinct categories which corresponded sometimes surprisingly well to canonical art periods. The result was cross-validated on two complementary sets of artworks for two different groups of participants showing the stability of art interpretation. The second focus of this paper was on determining how far computational algorithms would be able to capture human performance or would be able in general to separate different art categories. Using several state-of-the-art algorithms from computer vision, we found that whereas low-level appearance information can give some clues about category membership, human grouping strategies included also much higher-level concepts.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TYG-4W6Y829-1-S&_cdi=5618&_user=29041&_orig=search&_coverDate=08%2F31%2F2009&_sk=999669995&view=c&wchp=dGLbVzW-zSkWA&md5=26d1582bdc926c6b79e4abe6c4f3b637&ie=/sdarticle.pdf}, state = {published}, DOI = {10.1016/j.cag.2009.04.003}, author = {Wallraven C{walli}{Department Human Perception, Cognition and Action}, Fleming R{roland}{Department Human Perception, Cognition and Action}, Cunningham DW{dwc}{Department Human Perception, Cognition and Action}, Rigau J, Feixas M and Sbert M} } @Article{ 5995, title = {Seeing the hand while reaching speeds up on-line responses to a sudden change in target position}, journal = {The Journal of Physiology}, year = {2009}, month = {8}, volume = {587}, number = {19}, pages = {4605-4616}, web_url = {http://jp.physoc.org/content/early/2009/08/10/jphysiol.2009.176362.abstract}, state = {published}, DOI = {10.1113/jphysiol.2009.176362}, author = {Reichenbach A{areichen}{Department Human Perception, Cognition and Action}{Department High-Field Magnetic Resonance}, Thielscher A{thielscher}{Department High-Field Magnetic Resonance}, Peer A, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}} } @Article{ 6036, title = {A multisensory approach to spatial updating: the case of mental rotations}, journal = {Experimental Brain Research}, year = {2009}, month = {7}, volume = {197}, number = {1}, pages = {59-68}, abstract = {Mental rotation is the capacity to predict the outcome of spatial relationships after a change in viewpoint. These changes arise either from the rotation of the test object array or from the rotation of the observer. Previous studies showed that the cognitive cost of mental rotations is reduced when viewpoint changes result from the observer’s motion, which was explained by the spatial updating mechanism involved during self-motion. However, little is known about how various sensory cues available might contribute to the updating performance. We used a Virtual Reality setup in a series of experiments to investigate table-top mental rotations under different combinations of modalities among vision, body and audition. We found that mental rotation performance gradually improved when adding sensory cues to the moving observer (from None to Body or Vision and then to Body & Audition or Body & Vision), but that the processing time drops to the same level for any of the sensor y contexts. These results are discussed in terms of an additive contribution when sensory modalities are co-activated to the spatial updating mechanism involved during self-motion. Interestingly, this multisensory approach can account for different findings reported in the literature.}, file_url = {/fileadmin/user_upload/files/publications/A-multisensory-approach-Vidal-Lehmann-hhb_[0].pdf}, web_url = {http://www.springerlink.com/content/9511k45076051x66/}, state = {published}, DOI = {10.1007/s00221-009-1892-4}, author = {Vidal M{vidal}{Department Human Perception, Cognition and Action}, Lehmann A and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 6096, title = {Dissociable Perceptual Effects of Visual Adaptation}, journal = {PLoS ONE}, year = {2009}, month = {7}, volume = {4}, number = {7}, pages = {1-8}, abstract = {Neurons in the visual cortex are responsive to the presentation of oriented and curved line segments, which are thought to act as primitives for the visual processing of shapes and objects. Prolonged adaptation to such stimuli gives rise to two related perceptual effects: a slow change in the appearance of the adapting stimulus (perceptual drift), and the distortion of subsequently presented test stimuli (adaptational aftereffects). Here we used a psychophysical nulling technique to dissociate and quantify these two classical observations in order to examine their underlying mechanisms and their relationship to one another. In agreement with previous work, we found that during adaptation horizontal and vertical straight lines serve as attractors for perceived orientation and curvature. However, the rate of perceptual drift for different stimuli was not predictive of the corresponding aftereffect magnitudes, indicating that the two perceptual effects are governed by distinct neural processes. Finally, the rate of perceptual drift for curved line segments did not depend on the spatial scale of the stimulus, suggesting that its mechanisms lie outside strictly retinotopic processing stages. These findings provide new evidence that the visual system relies on statistically salient intrinsic reference stimuli for the processing of visual patterns, and point to perceptual drift as an experimental window for studying the mechanisms of visual perception.}, web_url = {http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0006183}, state = {published}, DOI = {10.1371/journal.pone.0006183}, EPUB = {e6183}, author = {M\"uller K-M{kaim}{Department Human Perception, Cognition and Action}, Schillinger F{frieder}{Department Human Perception, Cognition and Action}, Do DH and Leopold DA{davidl}{Department Physiology of Cognitive Processes}} } @Article{ 4689, title = {Gaze behavior in face comparison: The roles of sex, task, and symmetry}, journal = {Attention, Perception and Psychophysics}, year = {2009}, month = {7}, volume = {71}, number = {5}, pages = {1107-1126}, abstract = {Knowing where people look on a face provides an objective insight into the information entering the visual system and into cognitive processes involved in face perception. In the present study, we recorded eye movements of human participants while they compared two faces presented simultaneously. Observers‘ viewing behavior and performance was examined in two tasks of parametrically varying difficulty, using two types of face stimuli (sex morphs and identity morphs). The frequency, duration, and temporal sequence of fixations on previously defined areas of interest in the faces were analyzed. As was expected, viewing behavior and performance varied with difficulty. Interestingly, observers compared predominantly the inner halves of the face stimuli—a result inconsistent with the general left-hemiface bias reported for single faces. Furthermore, fixation patterns and performance differed between tasks, independently of stimulus type. Moreover, we found differences in male and female participants‘ viewing behaviors, but only when the sex of the face stimuli was task relevant.}, web_url = {http://app.psychonomic-journals.org/content/71/5/1107.full.pdf+html}, state = {published}, DOI = {10.3758/APP.71.5.1107}, author = {Armann R{armann}{Department Human Perception, Cognition and Action} and B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Article{ 6638, title = {Learning illumination- and orientation-invariant representations of objects through temporal association}, journal = {Journal of Vision}, year = {2009}, month = {7}, volume = {9}, number = {7:6}, pages = {1-8}, abstract = {As the orientation or illumination of an object changes so does its appearance. This paper considers how observers are nonetheless able to recognize objects that have undergone such changes. In particular the paper tests the hypothesis that observers rely on temporal correlations between different object views to decide whether they are views of the same object or not. In a series of experiments subjects were shown a sequence of views representing a slowly transforming object. Testing revealed that subjects had formed object representations which were directly influenced by the temporal characteristics of the training views. In particular, introducing spurious correlations between views of different people‘s heads caused subjects to regard those views as being of a single person. This rapid and robust overriding of basic generalization processes supports the view that our recognition system tracks the correlated appearance of views of objects across time. Such view associations appear to allow the visual system to solve the view invariance problem without recourse to complex illumination models for extracting 3D form, or the use of the image plane transformations required to make appearance-based comparisons.}, web_url = {http://www.journalofvision.org/content/9/7/6.full.pdf+html}, state = {published}, DOI = {10.1167/9.7.6}, author = {Wallis G{guy}{Department Human Perception, Cognition and Action}, Backus BT{backus}, Langer M{mlanger}, Huebner G and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 4688, title = {Learning influences the encoding of static and dynamic faces and their recognition across different spatial frequencies}, journal = {Visual Cognition}, year = {2009}, month = {7}, volume = {17}, number = {5}, pages = {716-735}, abstract = {Studies on face recognition have shown that observers are faster and more accurate at recognizing faces learned from dynamic sequences than those learned from static snapshots. Here, we investigated whether different learning procedures mediate the advantage for dynamic faces across different spatial frequencies. Observers learned two faces—one dynamic and one static—either in depth (Experiment 1) or using a more superficial learning procedure (Experiment 2). They had to search for the target faces in a subsequent visual search task. We used high-spatial frequency (HSF) and low-spatial frequency (LSF) filtered static faces during visual search to investigate whether the behavioural difference is based on encoding of different visual information for dynamically and statically learned faces. Such encoding differences may mediate the recognition of target faces in different spatial frequencies, as HSF may mediate featural face processing whereas LSF mediates configural processing. Our results show that the nature of the learning procedure alters how observers encode dynamic and static faces, and how they recognize those learned faces across different spatial frequencies. That is, these results point to a flexible usage of spatial frequencies tuned to the recognition task.}, web_url = {http://pdfserve.informaworld.com/178690_758077663_902406191.pdf}, state = {published}, DOI = {10.1080/13506280802340588}, author = {Pilz KS{kpilz}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Vuong QC{qvuong}{Department Human Perception, Cognition and Action}} } @Article{ 4961, title = {Adaptivity of wayfinding strategies in a multi-building ensemble: The effects of spatial structure, task requirements, and metric information}, journal = {Journal of Environmental Psychology}, year = {2009}, month = {6}, volume = {29}, number = {2}, pages = {208-219}, abstract = {This study investigates the adaptivity of wayfinding strategies in a real-world setting of a multi-building ensemble. Familiarity with the environment, map usage and verbal vs. visual task instructions were systematically varied. Measures included path choices, wayfinding performance and information usage. Thirty-two participants had to find eight goals in a multi-level building ensemble consisting of two distinctive building parts. It was tested whether the standard wall-mounted floor maps found in the majority of public buildings can help navigation in a complex unknown environment. Unfamiliar users tried to make use of these plans more frequently, but were not able to compensate for spatial knowledge deficits compared to participants familiar with the setting. Two strategies of multi-level wayfinding were compared with respect to a region-based hierarchical planning approach. Strategy selection could be shown to be highly adaptive to spatial properties of the environment as well as characteristics of the task instruction, i.e., spatial precision of target information. Overall, the strategy of moving horizontally into the target building prior to vertical travel was shown to be more effective in this multi-building setting.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6WJ8-4SRKMMV-1-1&_cdi=6872&_user=29041&_orig=search&_coverDate=06%2F13%2F2008&_sk=999999999&view=c&wchp=dGLzVlz-zSkzV&md5=a570}, state = {published}, DOI = {10.1016/j.jenvp.2008.05.010}, author = {H\"olscher C, B\"uchner SJ, Meilinger T{meilinger}{Department Human Perception, Cognition and Action} and Strube G} } @Article{ 5679, title = {BOLD signal in intraparietal sulcus covaries with magnitude of implicitly driven attention shifts}, journal = {NeuroImage}, year = {2009}, month = {5}, volume = {45}, number = {4}, pages = {1314-1328}, abstract = {A lot is known about the neural basis of directing attention based on explicit cues. In real life however, attention shifts are rarely directed by explicit cues but rather generated implicitly, for example on the basis of previous experience with a given situation. Here, we aimed at studying attention shifts dependent on recent trial history. While explicitly cued attention shifts involve activity in cortex of the intraparietal sulcus, whether this region is also involved in shifting attention according to recent history is still unknown. We asked observers to detect targets in a stream of visual stimuli with three feature dimensions: Color, shape and motion. Critically, target occurrence probability was always higher in one stimulus dimension than in the others, and probabilities switched between dimensions over blocks of trials. After each probability switch, target detection times decreased exponentially for high-probability targets and increased for low-probability targets, compatible with gradual shifts in attention dependent on trial history since the switch. BOLD signal in left prefrontal and intraparietal sulcus regions was higher in the early phase after the switch, while anterior cingulate, cuneus, precuneus, temporal and more anterior frontal regions showed more activation later after the switch. These findings are compatible with the engagement of regions involved in the establishment and maintenance of attentional sets. BOLD signal in left intraparietal sulcus correlated with the size of the performance changes consecutive to the detected targets, suggesting that it reflects the size of attention shifts induced by updating target probabilities over recent trial history.}, file_url = {/fileadmin/user_upload/files/publications/SchultzLennert_Stream_accepted_withFigs_formatted_5679[0].pdf}, state = {published}, DOI = {10.1016/j.neuroimage.2009.01.012}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action} and Lennert T{lennert}{Department Human Perception, Cognition and Action}} } @Article{ 5516, title = {Measurement of instantaneous perceived self-motion using continuous pointing}, journal = {Experimental Brain Research}, year = {2009}, month = {5}, volume = {195}, number = {3}, pages = {429-444}, abstract = {In order to optimally characterize full-body self-motion perception during passive translations, changes in perceived location, velocity, and acceleration must be quantified in real time and with high spatial resolution. Past methods have failed to effectively measure these critical variables. Here, we introduce continuous pointing as a novel method with several advantages over previous methods. Participants point continuously to the mentally updated location of a previously viewed target during passive, full-body movement. High-precision motion-capture data of arm angle provide a measure of a participant’s perceived location and, in turn, perceived velocity at every moment during a motion trajectory. In two experiments, linear movements were presented in the absence of vision by passively translating participants with a robotic wheelchair or an anthropomorphic robotic arm (MPI Motion Simulator). The movement profiles included constant-velocity trajectories, two successive movement intervals separated by a b rief pause, and reversed-motion trajectories. Results indicate a steady decay in perceived velocity during constant-velocity travel and an attenuated response to mid-trial accelerations.}, web_url = {http://springerlink.metapress.com/content/t0625668v1651t45/fulltext.pdf}, state = {published}, DOI = {10.1007/s00221-009-1805-6}, author = {Siegle JH{jsiegle}, Campos JL{camposjl}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, Loomis JM{loomis} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 5912, title = {Natural, Metaphoric, and Linguistic Auditory Direction Signals Have Distinct Influences on Visual Motion Processing}, journal = {Journal of Neuroscience}, year = {2009}, month = {5}, volume = {29}, number = {20}, pages = {6490-6499}, abstract = {To interact with our dynamic environment, the brain merges motion information from auditory and visual senses. However, not only "natural" auditory MOTION, but also "metaphoric" de/ascending PITCH and SPEECH (e.g., "left/right"), influence the visual motion percept. Here, we systematically investigate whether these three classes of direction signals influence visual motion perception through shared or distinct neural mechanisms. In a visual-selective attention paradigm, subjects discriminated the direction of visual motion at several levels of reliability, with an irrelevant auditory stimulus being congruent, absent, or incongruent. Although the natural, metaphoric, and linguistic auditory signals were equally long and adjusted to induce a comparable directional bias on the motion percept, they influenced visual motion processing at different levels of the cortical hierarchy. A significant audiovisual interaction was revealed for MOTION in left human motion complex (hMT+/V5+) and for SPEECH in right intraparietal sulcus. In fact, the audiovisual interaction gradually decreased in left hMT+/V5+ for MOTION > PITCH > SPEECH and in right intraparietal sulcus for SPEECH > PITCH > MOTION. In conclusion, natural motion signals are integrated in audiovisual motion areas, whereas the influence of culturally learnt signals emerges primarily in higher-level convergence regions.}, web_url = {http://www.jneurosci.org/cgi/reprint/29/20/6490}, state = {published}, DOI = {10.1523/JNEUROSCI.5437-08.2009}, author = {Sadaghiani S{ssadaghi}{Department Human Perception, Cognition and Action}{Research Group Cognitive Neuroimaging}, Maier JX{jmaier}{Department Human Perception, Cognition and Action} and Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Article{ LiuWYCZS2009, title = {Neural correlates of size illusions: an event-related potential study}, journal = {NeuroReport}, year = {2009}, month = {5}, volume = {20}, number = {8}, pages = {809-814}, abstract = {The aim of this study was to investigate the neural correlates of size illusions. Participants were presented with a sphere of a fixed angular size positioned (i) at either a far or close position within a three-dimensional virtual scene or (ii) at either an upper or lower screen position on a plain gray background. The visual-evoked potentials were recorded while participants were required to fixate on and attend to the sphere. The results showed that the amplitude of visual P2 component was affected by sphere position in the three-dimensional scene condition only, suggesting that the activity level of the primary visual cortex was modulated by the size illusion at later stages of visual processing.}, web_url = {http://ovidsp.tx.ovid.com/sp-3.4.0b/ovidweb.cgi?&S=JPODFPINELDDPEODNCCLMDMCOBJCAA00&WebLinkReturn=Full+Text%3dL%7cS.sh.15.16%7c0%7c00001756-200905270-00014&PDFLink=FPDDNCMCMDODEL00%7c%2ffs046%2fovft%2flive%2fgv023%2f00001756%2f00001756-200905270-00014&PDF}, state = {published}, DOI = {10.1097/WNR.0b013e32832be7c0}, author = {Liu Q, Wu Y, Yang Q, Campos JL{camposjl}{Department Human Perception, Cognition and Action}, Zhang Q and Sun HJ} } @Article{ 5694, title = {Influence of the size of the field of view on motion perception}, journal = {Computers and Graphics}, year = {2009}, month = {4}, volume = {33}, number = {2}, pages = {139-146}, abstract = {Efficient navigation requires a good representation of body position/orientation in the environment and an accurate updating of this representation when the body-environment relationship changes. Such updating is based on the ability to correctly estimate the speed and amplitude of body displacements. Because navigation in virtual worlds often relies on the sole visual information, we investigated to which extent the size of the field of view (FoV) affects two basic aspects of motion perception: (i) the perceived amplitude of rotations about the body vertical axis (Experiment 1) and (ii) the perceived speed of forward translations (Experiment 2). Concerning the perception of rotation amplitude, we found that visual flow information gives rise to inaccurate and very variable estimations, with a systematic underestimation of rotations larger than 30 degrees. We also found that the accuracy of the estimations does not depend on the size of the FoV and that horizontal FoVs larger than 30 degrees do not improve the performance. Concerning speed perception, central FoVs smaller than 60 degrees gave rise to an underestimation of the visual speed. On the other hand, occluding the central area leaving only peripheral visual information available induced a systematic overestimation of visual speed, even when only the central 10 degrees of vision were occluded. Taken together, these results suggest that large FoVs are not required to estimate the amplitude of visual rotations about the vertical axis of the body, whereas central FoVs of at least 60 degrees are advisable when speed perception relies on visual flow information.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TYG-4VGF3VR-1-19&_cdi=5618&_user=29041&_orig=browse&_coverDate=04%2F30%2F2009&_sk=999669997&view=c&wchp=dGLbVtb-zSkWA&md5=b4f2f6958b3f6f5de18521e4480a296f&ie=/sdarticle.pdf}, state = {published}, DOI = {10.1016/j.cag.2009.01.003}, author = {Pretto P{pretto}{Department Human Perception, Cognition and Action}, Ogier M{mogier}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Bresciani J-P{bresciani}{Department Human Perception, Cognition and Action}} } @Article{ 5270, title = {Knowledge alters visual contrast sensitivity}, journal = {Attention, Perception and Psychophysics}, year = {2009}, month = {4}, volume = {71}, number = {3}, pages = {451-462}, abstract = {Previous research has shown that the visual system’s sensitivity to variations in luminance (visual contrast) within a particular area of the retina is affected by the ambient contrast levels in nearby regions in a bottom-up fashion. Specifically changes in the ambient contrast in areas surrounding the target area alter the sensitivity to visual contrast within the target area. More recently, it has been shown that paying attention to the target or target area modulates contrast sensitivity suggesting a top-down influence over contrast sensitivity that is mediated by attention. Here we report another form of top-down influence over contrast sensitivity that is unlikely to be mediated by attention. In particular, we show that knowledge and/or expectations about the levels of visual contrast that may appear in upcoming targets also affects how sensitive the observer is to the contrast in the target. This sort of knowledge-driven, top-down contrast sensitivity control could be used to preset the visual system’ s contrast sensitivity to maximize discriminability and to protect contrast-sensitive processes from a contrast-overload. Overall, our results suggest that existing models of contrast sensitivity might benefit from the inclusion of top-down control mechanisms.}, file_url = {/fileadmin/user_upload/files/publications/delaRosaetal_KnowledgeAltersContrastSensitivity_2009_APP_5270[0].pdf}, state = {published}, DOI = {10.3758/APP.71.3.451}, author = {de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Schneider B and Gordon M} } @Article{ 5106, title = {Music and Motion: How Music-Related Ancillary Body Movements Contribute to the Experience of Music}, journal = {Music Perception}, year = {2009}, month = {4}, volume = {26}, number = {4}, pages = {335-353}, abstract = {Expressive performer movements in musical performances represent implied levels of communication and can contain certain characteristics and meanings of embodied human expressivity. This study investigated the contribution of ancillary body movements on the perception of musical performances. Using kinematic displays of four clarinetists, perceptual experiments were conducted in which participants were asked to rate specific music-related dimensions of the performance and the performer. Additionally, motions of particular body parts, such as movements of the arms and torso, as well as motion amplitudes of the whole body were manipulated in the kinematic display. It was found that manipulations of arm and torso movements have fewer effects on the observers‘ ratings of the musicians than manipulations concerning the movement of the whole body. The results suggest that the multimodal experience of musicians is less dependent on the players‘ particular body motion behaviors than it is on the players‘ overall relative motion characteristics.}, web_url = {http://caliber.ucpress.net/doi/abs/10.1525/mp.2009.26.4.335?prevSearch=allfield%253A%2528nusseck%2529&searchHistoryKey=}, state = {published}, DOI = {10.1525/mp.2009.26.4.335}, author = {Nusseck M{manfred}{Department Human Perception, Cognition and Action} and Wanderley MM} } @Article{ 5678, title = {Natural facial motion enhances cortical responses to faces}, journal = {Experimental Brain Research}, year = {2009}, month = {4}, volume = {194}, number = {3}, pages = {465-475}, abstract = {The ability to perceive facial motion is important to successfully interact in social environments. Previously, imaging studies have investigated neural correlates of facial motion primarily using abstract motion stimuli. Here, we studied how the brain processes natural non-rigid facial motion in direct comparison to static stimuli and matched phase-scrambled controls. As predicted from previous studies, dynamic faces elicit higher responses than static faces in lateral temporal areas corresponding to hMT+/V5 and STS. Interestingly, analyses of individually-defined, static-face-sensitive regions in bilateral fusiform gyrus and left inferior occipital gyrus also respond more to dynamic than static faces. These results suggest integration of form and motion information during the processing of dynamic faces even in ventral temporal and inferior lateral occipital areas. In addition, our results show that dynamic stimuli are a robust tool to localize areas related to the processing of static and dynamic face info rmation.}, file_url = {/fileadmin/user_upload/files/publications/SchultzPilz_facelocaliser_acceptedWithFigs_5678[0].pdf}, web_url = {http://www.springerlink.com/content/2l46216834155751/}, state = {published}, DOI = {10.1007/s00221-009-1721-9}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action} and Pilz KS{kpilz}{Department Human Perception, Cognition and Action}} } @Article{ 5819, title = {The N2pc component in ERP and the lateralization effect of language on color perception}, journal = {Neuroscience Letters}, year = {2009}, month = {4}, volume = {454}, number = {1}, pages = {58-61}, abstract = {This study examined the electrophysiological bases of the effect of language on color perception. In a visual search task, a target was presented to the left or right visual field. The target color was either from the same category as a set of distractors (within-category condition) or from a different category (between-category condition). For both category conditions, the targets elicited a clear N2pc (N2-posterior-contralateral) component in the event-related potential (ERP) in the contralateral hemisphere. In the left hemisphere only, the N2pc amplitude for the between-category condition was larger than that for the within-category condition. These results indicate that the N2pc could be used as an index to describe the lateralization effect of language on color perception.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6T0G-4VPM5J1-7-3&_cdi=4862&_user=29041&_pii=S0304394009002353&_orig=search&_coverDate=04%2F17%2F2009&_sk=995459998&view=c&wchp=dGLzVtz-zSkWA&md5=dd541e3a83310fa38f9716a8b76f6b3a&ie=/sdarticle.pdf}, state = {published}, DOI = {10.1016/j.neulet.2009.02.045}, author = {Liu Q, Li H, Campos JL{camposjl}{Department Human Perception, Cognition and Action}, Wang Q, Zhang Y, Qiu J, Zhang Q and Sun H-J} } @Article{ 6094, title = {Using mobile group dynamics and virtual time to improve teamwork in large-scale collaborative virtual environments}, journal = {Computers & Graphics}, year = {2009}, month = {4}, volume = {33}, number = {2}, pages = {130-138}, abstract = {Mobile group dynamics (MGDs) assist synchronous working in collaborative virtual environments (CVEs), and virtual time (VT) extends the benefits to asynchronous working. The present paper describes the implementation of MGDs (teleporting, awareness and multiple views) and VT (the utterances of 23 previous users were embedded in a CVE as conversation tags), and their evaluation using an urban planning task. Compared with previous research using the same scenario, the new MGD techniques produced substantial increases in the amount that, and distance over which, participants communicated. With VT participants chose to listen to a quarter of the conversations of their predecessors while performing the task. The embedded VT conversations led to a reduction in the rate at which participants traveled around, but an increase in live communication that took place. Taken together, the studies show how CVE interfaces can be improved for synchronous and asynchronous collaborations, and highlight possibilities for future research.}, file_url = {/fileadmin/user_upload/files/publications/computersgraphics09_6094[0].pdf}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TYG-4VG5HY5-1-10&_cdi=5618&_user=29041&_pii=S0097849309000144&_orig=search&_coverDate=04%2F30%2F2009&_sk=999669997&view=c&wchp=dGLbVzb-zSkzk&md5=1da33bd23cab40845ffa464e4a4068a8&ie=/sdarticle.pdf}, state = {published}, DOI = {doi:10.1016/j.cag.2009.01.001}, author = {Dodds TJ{dodds}{Department Human Perception, Cognition and Action} and Ruddle RA{roy}} } @Article{ 5451, title = {Bayesian models of eye movement selection with retinotopic maps}, journal = {Biological Cybernetics}, year = {2009}, month = {3}, volume = {100}, number = {3}, pages = {203-214}, abstract = {Among the various possible criteria guiding eye movement selection, we investigate the role of position uncertainty in the peripheral visual eld. In particular, we suggest that, in everyday life situations of object tracking, eye movement selection probably includes a principle of reduction of uncertainty. To do so, we confront the movement predictions of computational models with human results from a psychophysical task. This task is a freely moving eye version of the Multiple Object Tracking task with the eye movements possibly compensating for lower peripheral resolution. We design several Bayesian models of increasing complexity, whose layered structures are inspired by the neurobiology of the brain areas implied in eye movement selection. Finally, we compare the relative performances of these models with regard to the prediction of the recorded human movements, and show the advantage of taking explicitly into account uncertainty for the prediction of eye movements.}, web_url = {http://www.springerlink.com/content/t24521715tq54737/fulltext.pdf}, state = {published}, DOI = {10.1007/s00422-009-0292-y}, author = {Colas F, Flacher F, Tanner TG{tanner}{Department Human Perception, Cognition and Action}, Bessiere P and Girard B} } @Article{ 5707, title = {Humans and Macaques Employ Similar Face-Processing Strategies}, journal = {Current Biology}, year = {2009}, month = {3}, volume = {19}, number = {6}, pages = {509-513}, abstract = {Primates developed the ability to recognize and individuate their conspecifics by the face. Despite numerous electrophysiological studies in monkeys [1–3], little is known about the face-processing strategies that monkeys employ. In contrast, face perception in humans has been the subject of many studies [4–6] providing evidence for specific face processing that evolves with perceptual expertise [7]. Importantly, humans process faces holistically, here defined as the processing of faces as wholes, rather than as collections of independent features (part-based processing) [8]. The question remains to what extent humans and monkeys share these face-processing mechanisms. By using the same experimental design and stimuli for both monkey and human behavioral experiments, we show that face processing is influenced by the species affiliation of the observed face stimulus (human versus macaque face). Furthermore, stimulus manipulations that selectively reduced holistic and part-based information systematically altered eye-scanning patterns for human and macaque observers similarly. These results demonstrate the similar nature of face perception in humans and monkeys and pin down effects of expert faceprocessing versus novice face-processing strategies. These findings therefore directly contribute to one of the central discussions in the behavioral and neurosciences about how faces are perceived in primates.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6VRT-4VPN17C-5-2&_cdi=6243&_user=29041&_orig=search&_coverDate=03%2F24%2F2009&_sk=999809993&view=c&wchp=dGLzVzz-zSkzk&md5=e6f38dd7719b33b8f0c6b73ddac9cc6f&ie=}, state = {published}, DOI = {10.1016/j.cub.2009.01.061}, author = {Dahl CD{dahl}{Department Human Perception, Cognition and Action}{Department Physiology of Cognitive Processes}, Wallraven C{walli}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Logothetis NK{nikos}{Department Physiology of Cognitive Processes}} } @Article{ 5583, title = {Circular, linear, and curvilinear vection in a large-screen virtual environment with floor projection}, journal = {Computers and Graphics}, year = {2009}, month = {2}, volume = {33}, number = {1}, pages = {47-58}, abstract = {Vection is defined as the compelling sensation of illusory self-motion elicited by a moving sensory, usually visual, stimulus. This paper presents collected introspective data, user discomfort and perceived speed data for the experience of linear, circular, and curvilinear vection in a large-screen, immersive, virtual environment. As a first step we evaluated the effectiveness of a floor projection on the perception of vection for four trajectories: linear forward, linear backward, circular left, and circular right. The floor projection, which considerably extended the field of view, was found to significantly improve the introspective measures of linear, but not circular, vection experienced in a photo-realistic three-dimensional town. In a second study we investigated the differences between 12 different motion trajectories on the illusion of self-motion. In this study we found that linear translations to the left and right are perceived as the least convincing, while linear down is perceived as the most convincing of the linear trajectories. Second, we found that while linear forward vection is not perceived to be very convincing, curvilinear forward vection is reported to be as convincing as circular vection. In a third and final experiment we investigated the perceived speed for all different trajectories and acquired data based on simulator sickness questionnaires to compute a discomfort factor associated with each type of trajectory. Considering our experimental results, we offer suggestions for increasing the sense of self-motion in simulators and VE applications, specifically to increase the number of curvilinear trajectories (as opposed to linear ones) and, if possible, add floor projection in order to improve the illusory sense of self-motion.}, web_url = {http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TYG-4V3SY6B-1-1M&_cdi=5618&_user=29041&_orig=browse&_coverDate=02%2F28%2F2009&_sk=999669998&view=c&wchp=dGLbVzz-zSkzV&md5=1d4}, state = {published}, DOI = {10.1016/j.cag.2008.11.008}, author = {Trutoiu LC{auract}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action}, Schulte-Pelkum J{jsp}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ 6103, title = {Moving sounds enhance the visually-induced self-motion illusion (circular vection) in virtual reality}, journal = {ACM Transactions on Applied Perception}, year = {2009}, month = {2}, volume = {6}, number = {2:7}, pages = {1-27}, abstract = {While rotating visual and auditory stimuli have long been known to elicit self-motion illusions (“circular vection”), audiovisual interactions have hardly been investigated. Here, two experiments investigated whether visually induced circular vection can be enhanced by concurrently rotating auditory cues that match visual landmarks (e.g., a fountain sound). Participants sat behind a curved projection screen displaying rotating panoramic renderings of a market place. Apart from a no-sound condition, headphone-based auditory stimuli consisted of mono sound, ambient sound, or low-/high-spatial resolution auralizations using generic head-related transfer functions (HRTFs). While merely adding nonrotating (mono or ambient) sound showed no effects, moving sound stimuli facilitated both vection and presence in the virtual environment. This spatialization benefit was maximal for a medium (20 × 15) FOV, reduced for a larger (54 × 45) FOV and unexpectedly absent for the smallest (10 × 7.5) FOV. Increasing auraliza tion spatial fidelity (from low, comparable to five-channel home theatre systems, to high, 5 resolution) provided no further benefit, suggesting a ceiling effect. In conclusion, both self-motion perception and presence can benefit from adding moving auditory stimuli. This has important implications both for multimodal cue integration theories and the applied challenge of building affordable yet effective motion simulators.}, web_url = {http://portal.acm.org/citation.cfm?id=1498700.1498701&coll=portal&dl=ACM&idx=J932&part=transaction&WantType=Transactions&title=ACM%20Transactions%20on%20Applied%20Perception%20(TAP)&CFID=56761798&CFTOKEN=27688131}, state = {published}, DOI = {10.1145/1498700.1498701}, author = {Riecke BE{bernie}{Department Human Perception, Cognition and Action}, V\"aljam\"ae A and Schulte-Pelkum J{jsp}{Department Human Perception, Cognition and Action}} } @Article{ 6219, title = {Guest editorial: Special issue on Applied Perception in Graphics and Visualization (APGV07)}, journal = {ACM Transactions on Applied Perception}, year = {2009}, month = {1}, volume = {5}, number = {4:18}, web_url = {http://dl.acm.org/citation.cfm?doid=1462048.1462049}, state = {published}, DOI = {10.1145/1462048.1462049}, author = {Fleming RW{roland}{Department Human Perception, Cognition and Action} and Langer M{mlanger}} } @Inproceedings{ 6129, title = {Control design and experimental evaluation of the 2D CyberWalk platform}, journal = {Proceedings of the 2009 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2009)}, year = {2009}, month = {10}, pages = {5051-5058}, abstract = {The CyberWalk is a large size 2D omni-directional platform that allows unconstrained locomotion possibilities to a walking user for VR exploration. In this paper we present the motion control design for the platform, which has been developed within the homonymous European research project. The objective is to compensate the intentional motion of the user, so as to keep her/him always close to the platform center while limiting the perceptual effects due to actuation commands. The controller acts at the acceleration level, using suitable observers to estimate the unmeasurable intentional walker‘s velocity and acceleration. A moving reference position is used to limit the accelerations felt by the user in critical transients, e.g., when the walker suddenly stops motion. Experimental results are reported that show the benefit of designing separate control gains in the two orthogonal directions (lateral and sagittal) of a frame attached to the walker.}, file_url = {/fileadmin/user_upload/files/publications/IROS09_CyberWalk_submitted_6129[0].pdf}, web_url = {http://www.iros09.mtu.edu/index.php/IROS_2009:_The_2009_IEEE/RSJ_International_Conference_on_Intelligent_RObots_and_Systems}, publisher = {IEEE Service Center}, address = {Piscataway, NJ, USA}, event_name = {2009 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2009)}, event_place = {St. Louis, MO, USA}, state = {published}, ISBN = {978-1-424-43803-7}, DOI = {10.1109/IROS.2009.5354610}, author = {De Luca A, Mattone R, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5899, title = {Markerless 3D Face Tracking (DAGM 2009)}, journal = {Pattern Recognition: 31st DAGM Symposium}, year = {2009}, month = {9}, pages = {41-50}, abstract = {We present a novel algorithm for the markerless tracking of deforming surfaces such as faces. We acquire a sequence of 3D scans along with color images at 40Hz. The data is then represented by implicit surface and color functions, using a novel partition-of-unity type method of efficiently combining local regressors using nearest neighbor searches. Both these functions act on the 4D space of 3D plus time, and use temporal information to handle the noise in individual scans. After interactive registration of a template mesh to the first frame, it is then automatically deformed to track the scanned surface, using the variation of both shape and color as features in a dynamic energy minimization problem. Our prototype system yields high-quality animated 3D models in correspondence, at a rate of approximately twenty seconds per timestep. Tracking results for faces and other objects are presented.}, file_url = {/fileadmin/user_upload/files/publications/WalderEtAl_DAGM2009_5899[0].pdf}, web_url = {http://www.dagm2009.org/index.php/main.html}, editor = {Denzler, J. , G. Notni, H. Süsse}, publisher = {Springer}, address = {Berlin, Germany}, booktitle = {Pattern Recognition}, event_name = {31. Symposium of the German Association for Pattern Recognition (DAGM 2009)}, event_place = {Jena, Germany}, state = {published}, ISBN = {978-3-642-03798-6}, DOI = {10.1007/978-3-642-03798-6_5}, author = {Walder C{walder}{Department Empirical Inference}{Department Human Perception, Cognition and Action}, Breidt M{mbreidt}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Sch\"olkopf B{bs}{Department Empirical Inference} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5944, title = {Perzeptuell motivierte illustrative Darstellungsstile für komplexe Modelle}, journal = {Grenzenlos frei?! : Workshop-Proceedings der Tagung Mensch & Computer 2009 (M&C 2009)}, year = {2009}, month = {9}, pages = {311-316}, abstract = {Illustrationen werden erfolgreich in den Ingenieurwissenschaften, den Naturwissenschaften und der Medizin zur abstrahierten Darstellung von Objekten und Situationen verwendet. Typischerweise sind diese Illustrationen Zeichnungen, bei denen der Illustrator künstlerische Techniken zur Betonung relevanter Aspekte der Objekte einsetzt. Im Gegensatz dazu erzeugen Visualisierungen eine direkte, nicht abstrahierte visuelle Darstellung von Simulationen, gescannten Objekten oder modellierten Daten. Durch die inhärente Komplexität dieser Datensätze stellt sich die Interpretation dieser Daten jedoch oft als schwierig dar. Die illustrative Visualisierung hingegen versucht beide Ansätze zur einer abstrahierten Darstellung eines Datensatzes zu verbinden, in der die wesentlichen Charakteristika betont werden. Dieser Ansatz bekommt eine besondere Bedeutung bei sehr komplexen Modellen, die u.U. aus vielen einzelnen Objekten bestehen, wie z.B. einzelne Bauteile einer Maschine, oder segmentierten Organen aus einem CT- oder MRT-Datensatz eines Menschen. Während im Allgemeinen die illustrative Visualisierung einer bessere Betonung ausgewählter und relevanter Informationen als die traditionelle Visualisierung erreicht, so stellen viele nah beieinander gelegene Objekte eine Herausforderung dar, da sie klar von einander getrennt werden müssen.}, file_url = {/fileadmin/user_upload/files/publications/MenschUndComputer2009-Salah_5944[0].pdf}, web_url = {http://www2.hu-berlin.de/mc2009/}, editor = {Wandke, H. , S. Kain, D. Struve}, publisher = {Logos}, address = {Berlin, Germany}, booktitle = {Grenzenlos frei?}, event_name = {Workshop der Tagung Mensch & Computer 2009}, event_place = {Berlin, Germany}, state = {published}, ISBN = {978-3-8325-2181-3}, author = {Salah Z, Cunningham DW{dwc}{Department Human Perception, Cognition and Action} and Bartz D} } @Inproceedings{ 5975, title = {The Effect of Simulator Motion on Pilot Control Behaviour for Agile and Inert Helicopter Dynamics}, journal = {35th European Rotorcraft Forum (ERF 2009)}, year = {2009}, month = {9}, pages = {1051-1063}, abstract = {Even though simulators are often used in flight training, the effects of the different motion components on pilot performance and control behaviour are still not fully understood. In most hexapod motion base simulators the translational motion needs to be reduced significantly to fit within the limited motion space, while the rotational motion might not need attenuation. This paper presents the results of an experiment that investigated the effects of simulator motion in a roll-lateral helicopter control task for both agile and inert helicopter dynamics. The experiment was performed in the MPI Motion Simulator, which has the unique ability of presenting the motion in this task 1-to-1. The results indicate that both roll and lateral motion are important for increasing performance in reducing the roll error. The lateral motion also significantly reduced the lateral tracking errors. Pilots increased their control activity, but had a lower performance in reducing the lateral error for the inert helicopter dynamics. These effects in performance and control activity were caused by a change in the pilots’ control strategy as was observed from the multimodal pilot model parameters. The effects on pilot tracking performance were also apparent from a significant change in the disturbance and target open-loop characteristics.}, web_url = {http://www.erf2009.org}, editor = {Lopez, L. , P. Brandt}, publisher = {Deutsche Gesellschaft für Luft- und Raumfahrt}, address = {Bonn, Germany}, event_name = {35th European Rotorcraft Forum (ERF 2009)}, event_place = {Hamburg, Germany}, state = {published}, ISBN = {978-3-932182-65-0}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, Zaal PMT, Teufel H{teufel}{Department Human Perception, Cognition and Action}, Mulder M and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5936, title = {The interaction between motion and form in expression recognition}, journal = {Proceedings of the 6th Symposium on Applied Perception in Graphics and Visualization (APGV 2009)}, year = {2009}, month = {9}, pages = {41-44}, abstract = {Faces are a powerful and versatile communication channel. Physically, facial expressions contain a considerable amount of information, yet it is clear from stylized representations such as cartoons that not all of this information needs to be present for efficient processing of communicative intent. Here, we use a high-fidelity facial animation system to investigate the importance of two forms of spatial information (connectivity and the number of vertices) for the perception of intensity and the recognition of facial expressions. The simplest form of connectivity is point light faces. Since they show only the vertices, the motion and configuration of features can be seen but the higher-frequency spatial deformations cannot. In wireframe faces, additional information about spatial configuration and deformation is available. Finally, full-surface faces have the highest degree of static information. The results of two experiments are presented. In the first, the presence of motion was manipulated. In the second, the size of the images was varied. Overall, dynamic expressions performed better than static expressions and were largely impervious to the elimination of shape or connectivity information. Decreasing the size of the image had little effect until a critical size was reached. These results add to a growing body of evidence that shows the critical importance of dynamic information for processing of facial expressions: As long as motion information is present, very little spatial information is required.}, web_url = {http://www.apgv.org/}, editor = {Mania, K. , B. E. Riecke, S. N. Spencer, B. Bodenheimer, C. O Sullivan}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {6th Symposium on Applied Perception in Graphics and Visualization (APGV 2009)}, event_place = {Chania, Crete, Greece}, state = {published}, ISBN = {978-1-60558-743-1}, DOI = {10.1145/1620993.1621002}, author = {Cunningham DW{dwc}{Department Human Perception, Cognition and Action} and Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5861, title = {Does jerk have to be considered in linear motion simulation?}, journal = {Proceedings of the AIAA Modeling and Simulation Technologies Conference (AIAA 2009)}, year = {2009}, month = {8}, pages = {1381-1388}, abstract = {Perceptual thresholds for the detection of the direction of linear motion are important for motion simulation. There are situations in which a subject should not perceive the motion direction as, e.g., during repositioning of a simulator, but also opposite cases where a certain motion percept must intentionally be induced in the subject. The exact dependency of the perceptual thresholds on the time evolution of the presented motion profile is still an open question. Previous studies have found evidence for a sensitivity of the thresholds on the rate of change of acceleration, called jerk. In this study we investigate three motion profiles which differ in their jerk characteristics. We want to evaluate which profile can move people furthest in the horizontal plane in a given time without them noticing the direction. Our results suggest that a profile with a minimum peak jerk value should be chosen.}, file_url = {/fileadmin/user_upload/files/publications/AIAA2009-Soyka-kurz.pdf}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2009-6245}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference 2009}, event_place = {Chicago, IL, USA}, state = {published}, ISBN = {978-1-62410-161-8}, DOI = {10.2514/6.2009-6245}, author = {Soyka F{fsoyka}{Department Human Perception, Cognition and Action}, Teufel H{teufel}{Department Human Perception, Cognition and Action}, Beykirch K{kab}{Department Human Perception, Cognition and Action}, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Butler J{butler}{Department Human Perception, Cognition and Action}, Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6101, title = {Gaze-Assisted Pointing for Wall-Sized Displays}, journal = {Human-Computer Interaction: INTERACT 2009}, year = {2009}, month = {8}, pages = {9-12}, abstract = {Previous studies have argued for the use of gaze-assisted pointing techniques (MAGIC) in improving human-computer interaction. Here, we present experimental findings that were drawn from human performance of two tasks on a wall-sized display. Our results show that a crude adoption of MAGIC across a range of complex tasks does not increase pointing performance. More importantly, a detailed analysis of user behavior revealed several issues that were previously ignored (such as, interference of corrective saccades, increased decision time due to variability of precision, errors due to eye-hand asynchrony, and interference with search behavior) which should influence the development of gaze-assisted technology.}, web_url = {http://www.interact2009.org/}, editor = {Gross, T. , J. Gulliksen, P. Kotze, L. Oestreicher, P. Palanque, R. Oliveira Prates, M. Winckler}, publisher = {Springer}, address = {Berlin, Germany}, booktitle = {Human-Computer Interaction: INTERACT 2009}, event_name = {12th IFIP TC13 International Conference on Human-Computer Interaction}, event_place = {Uppsala, Sweden}, state = {published}, ISBN = {978-3-642-03658-3}, DOI = {10.1007/978-3-642-03658-3_3}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}, Chuang LL{chuang}{Department Human Perception, Cognition and Action} and Reiterer H} } @Inproceedings{ 5709, title = {Spatial Memory for Highly Familiar Environments}, journal = {Proceedings of the 31st Annual Conference of the Cognitive Science Society (CogSci 2009)}, year = {2009}, month = {8}, pages = {2650-2655}, abstract = {In this experiment we examined orientation dependency in human memory for a highly familiar environmental space. Twenty-seven inhabitants living for at least two years in Tübingen saw a photorealistic virtual model of the city center (Virtual Tübingen) through a head-mounted display. They were teleported to five different initial locations in Virtual Tübingen and asked to point towards well-known target locations. This procedure was repeated in twelve different body-orientations for each of the initial locations. Participants pointed more accurately when oriented northwards regardless of the initial location. We also found a small effect of local orientation. The more participants were aligned with the street leading to the target location the better was their pointing performance. Even though the strong alignment effect with a global orientation is predicted by reference direction theory, this theory does not predict that this global orientation is, first, common for almost all participants, and second, t hat this orientation is north. We discuss our results with respect to well-known theories of spatial memory and speculate that the bias we find for north orientation is due to participants relying on memory of a city map of Tübingen for their pointing response.}, file_url = {/fileadmin/user_upload/files/publications/CogSci2009-Frankenstein_5709[0].pdf}, web_url = {http://csjarchive.cogsci.rpi.edu/proceedings/2009/index.html}, editor = {Taatgen, N. , H. Van Rijn}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {31st Annual Conference of the Cognitive Science Society (CogSci 2009)}, event_place = {Amsterdam, Netherlands}, state = {published}, ISBN = {978-0-9768318-5-3}, author = {Frankenstein J{frankenstein}{Department Human Perception, Cognition and Action}, Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Mohler BJ{mohler}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6227, title = {Towards Real-Time Aircraft Simulation with the MPI Motion Simulator}, journal = {Proceedings of the 2009 AIAA Modeling and Simulation Technologies Conference}, year = {2009}, month = {8}, pages = {623-632}, abstract = {The paper describes the recent advancements gained on the MPI motion simulator project. The aim of this project is the use of an anthropomorphic robot as actuation system for a motion platform intended for real time flight simulation. Almost all commercially available motion platforms rely on the so called Stewart platform, that is a 6-DOF platform that can bear high payloads and can achieve high accelerations. On the other hand an anthropomorphic manipulator offers a larger range of motion and higher dexterity, that let envisage this novel motion simulator as a viable and superior alternative [1,2]. The paper addresses the use of a new inverse kinematics algorithm capable of keeping joint velocities and accelerations within their limits. Preliminary experimental results performed using the proposed algorithm along with possible further improvements are discussed.}, file_url = {/fileadmin/user_upload/files/publications/simulatoronMPIplatform_[0].pdf}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2009-5918}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference 2009}, event_place = {Chicago, IL, USA}, state = {published}, ISBN = {978-1-62410-161-8}, DOI = {10.2514/6.2009-5918}, author = {Niccolini M, Pollini L{lpollini}, Innocenti M, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Teufel H{teufel}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5974, title = {Towards Simulating a Mid-size Stewart Platform on a Large Hexapod Simulator}, journal = {Proceedings of the 2009 AIAA Modeling and Simulation Technologies Conference}, year = {2009}, month = {8}, pages = {613-622}, abstract = {For a recent project on the influence of motion system characteristic on human perception and control behaviour, a dynamic model of the MPI Stewart platform was developed. The model parameters were estimated from measurements involving motion along a circular trajectory and frequency sweeps. Simulation results showed that the model response with optimised parameters was very close to the measured platform response. However, additional measurements are required to identify the platform mass and vertical centre of gravity position correctly. Validation of the dynamic model with platform measurements in heave showed favourable results. The dynamic model of the MPI Stewart platform will be validated further in multiple degrees-of-freedom and will be used in active closed-loop experiments.}, file_url = {/fileadmin/user_upload/files/publications/Nieuwenhuizen2009b_5974[0].pdf}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2009-5917}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference 2009}, event_place = {Chicago, IL, USA}, state = {published}, ISBN = {978-1-62410-161-8}, DOI = {10.2514/6.2009-5917}, author = {Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}, van Paassen MM, Mulder M, Beykirsch K{kab}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 6374, title = {Acquisition of human EEG data during linear self-motion on a Stewart platform}, journal = {Proceedings of the 4th International IEEE/EMBS Conference on Neural Engineering (NER 2009)}, year = {2009}, month = {5}, pages = {585-588}, abstract = {The present study investigated the feasibility of acquiring electroencephalography (EEG) data during self-motion in human subjects. Subjects performed a visual oddball task - designed to evoke a P3 event-related potential - while being passively moved in the fore-aft direction on a Stewart platform. The results of this study indicate that reliable EEG data can be obtained during self-motion on a Stewart platform: this finding is important for the ecological validity of further research into human motion.}, file_url = {/fileadmin/user_upload/files/publications/IEEE-EMBS-Conf-Neural-Engineering-2009-Nolan_[0].pdf}, web_url = {http://ne2009.engineering.asu.edu/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {4th International IEEE/EMBS Conference on Neural Engineering (NER 2009)}, event_place = {Antalya, Turkey}, state = {published}, ISBN = {978-1-4244-2072-8}, DOI = {10.1109/NER.2009.5109364}, author = {Nolan H, Whelan R, Reilly RB, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Butler JS{butler}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5740, title = {Aesthetic appraisal of art: from eye movements to computers}, journal = {Computational Aesthetics 2009 : Eurographics Workshop on Computational Aesthetics in Graphics, Visualization and Imaging}, year = {2009}, month = {5}, pages = {137-144}, abstract = {By looking at a work of art, an observer enters into a dialogue. In this work, we attempt to analyze this dialogue with both behavioral and computational tools. In two experiments, observers were asked to look at a large number of paintings from different art periods and to rate their visual complexity, or their aesthetic appeal. During these two tasks, their eye movements were recorded. The complexity and aesthetic ratings show clear preferences for certain artistic styles and were based on both low-level and high-level criteria. Eye movements reveal the time course of the aesthetic dialogue as observers try to interpret and understand the painting. Computational analyses of both the ratings (using measures derived from information theory) and the eye tracking data (using two models of saliency) showed that our computational tools are already able to explain some properties of this dialogue.}, file_url = {/fileadmin/user_upload/files/publications/CAe2009-Wallraven_5740[0].pdf}, web_url = {http://www.cs.rug.nl/svcg/cae2009/pmwiki.php/Main/Program}, editor = {Deussen, O. , D. W. Fellner, N. A. Dodgson}, publisher = {Eurographics}, address = {Aire-La-Ville, Switzerland}, booktitle = {Computational Aesthetics 2009}, event_name = {Eurographics Workshop on Computational Aesthetics in Graphics, Visualization and Imaging}, event_place = {Victoria, BC, Canada}, state = {published}, ISBN = {978-3-905674-17-0}, DOI = {10.2312/COMPAESTH/COMPAESTH09/137-144}, author = {Wallraven C{walli}{Department Human Perception, Cognition and Action}, Cunningham DW{dwc}{Department Human Perception, Cognition and Action}, Rigau J, Feixas M and Sbert M} } @Inproceedings{ 5736, title = {Image statistics for clustering paintings according to their visual appearance}, journal = {Computational Aesthetics 2009 : Eurographics Workshop on Computational Aesthetics in Graphics, Visualization and Imaging}, year = {2009}, month = {5}, pages = {57-64}, abstract = {Untrained observers readily cluster paintings from different art periods into distinct groups according to their overall visual appearance or 'look' [WCF08]. These clusters are typically influenced by both the content of the paintings (e.g. portrait, landscape, still-life, etc.), and stylistic considerations (e.g. the 'flat' appearance of Gothic paintings, or the distinctive use of colour in Fauve works). Here we aim to identify a set of image measurements that can capture this 'naïve visual impression of art', and use these features to automatically cluster a database of images of paintings into appearance-based groups, much like an untrained observer. We combine a wide range of features from simple colour statistics, through mid-level spatial features to high-level properties, such as the output of face-detection algorithms, which are intended to correlate with semantic content. Together these features yield clusters of images that look similar to one another despite differences in historical period and content. In addition, we tested the performance of the feature library in several classification tasks yielding good results. Our work could be applied as a curatorial or research aid, and also provides insight into the image attributes that untrained subjects may attend to when judging works of art.}, file_url = {/fileadmin/user_upload/files/publications/CAe2009_final_[0].pdf}, web_url = {http://www.cs.rug.nl/svcg/cae2009/pmwiki.php/Main/Program}, editor = {Deussen, O. , D. W. Fellner, N. A. Dodgson}, publisher = {Eurographics}, address = {Aire-La-Ville, Switzerland}, booktitle = {Computational Aesthetics 2009}, event_name = {Eurographics Workshop on Computational Aesthetics in Graphics, Visualization and Imaging}, event_place = {Victoria, BC, Canada}, state = {published}, ISBN = {978-3-905674-17-0}, DOI = {10.2312/COMPAESTH/COMPAESTH09/057-064}, author = {Spehr M{mspehr}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action} and Fleming RW{roland}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5760, title = {Medial Features for Superpixel Segmentation}, journal = {Proceedings of the Eleventh IAPR Conference on Machine Vision Applications (MVA 2009)}, year = {2009}, month = {5}, pages = {248-252}, abstract = {Image segmentation plays an important role in computer vision and human scene perception. Image oversegmentation is a common technique to overcome the problem of managing the high number of pixels and the reasoning among them. Specifically, a local and coherent cluster that contains a statistically homogeneous region is denoted as a superpixel. In this paper we propose a novel algorithm that segments an image into superpixels employing a new kind of shape centered feature which serve as a seed points for image segmentation, based on Gradient Vector Flow fields (GVF) [14]. The features are located at image locations with salient symmetry. We compare our algorithm to state-of-the-art superpixel algorithms and demonstrate a performance increase on the standard Berkeley Segmentation Dataset.}, file_url = {/fileadmin/user_upload/files/publications/mva2009_5760[0].pdf}, web_url = {http://www.mva-org.jp/mva2009/}, publisher = {MVA Organizing Committee}, address = {Tokyo, Japan}, event_name = {Eleventh IAPR Conference on Machine Vision Applications (MVA 2009)}, event_place = {Yokohama, Japan}, state = {published}, author = {Engel D{engel}{Department Human Perception, Cognition and Action}, Spinello L, Triebel R, Siegwart R, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Curio C{curio}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5892, title = {On the Kinematic Modeling and Control of a Mobile Platform Equipped with Steering Wheels and Movable Legs}, journal = {Proceedings of the 2009 IEEE International Conference on Robotics and Automation (ICRA 2009)}, year = {2009}, month = {5}, pages = {4080-4087}, abstract = {Mobile platforms equipped with several steering wheels are known to be omnidirectional, i.e., able to independently translate and rotate on the plane. As an improvement to this design, the Justin mobile platform also possesses the ability to vary its footprint over time by extending/retracting the wheel legs during motion. In this paper, we discuss the kinematic modeling and control issues for such a platform. The goal is to obtain a tracking controller which is able to realize an arbitrary linear/angular platform motion while, at the same time, independently expanding/retracting each leg. Experimental results support the proposed approach.}, file_url = {/fileadmin/user_upload/files/publications/legged_platform_ICRA09_[0].pdf}, web_url = {http://www.icra2009.org/}, publisher = {IEEE Service Center}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA '09)}, event_place = {Kobe, Japan}, state = {published}, ISBN = {978-1-4244-2788-8}, DOI = {10.1109/ROBOT.2009.5152625}, author = {Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Fuchs M, Albu-Sch\"affer A and Hirzinger G} } @Inproceedings{ 5894, title = {Rollin' Justin: Design considerations and realization of a mobile platform for a humanoid upper body}, journal = {Proceedings of the 2009 IEEE International Conference on Robotics and Automation (ICRA 2009)}, year = {2009}, month = {5}, pages = {4131-4137}, abstract = {Research on humanoid robots for use in servicing tasks, e.g. fetching and delivery, attracts steadily more interest. With Rollin‘ Justin a mobile robotic system and research platform is presented that allows the implementation and demonstration of sophisticated control algorithms and dexterous manipulation. Important problems of service robotics such as mobile manipulation and strategies for using the increased workspace and redundancy in manipulation task can be studied in detail. This paper gives an overview of the design considerations for a mobile platform and their realizations to transform the formerly table-mounted humanoid upper body system Justin into Rollin‘ Justin, a fully self-sustaining mobile research platform.}, file_url = {/fileadmin/user_upload/files/publications/platform%20paper_icra2009_final_[0].pdf}, web_url = {http://www.icra2009.org/}, publisher = {IEEE Service Center}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA '09)}, event_place = {Kobe, Japan}, state = {published}, DOI = {10.1109/ROBOT.2009.5152464}, author = {Fuchs M, Borst C, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Baumann A, Kraemer E, Langwald J, Gruber R, Seitz N, Plank G, Kunze K, Burger R, Schmidt F, Wimb\"ock T and Hirzinger G} } @Inproceedings{ 5893, title = {Rollin' Justin: Mobile platform with variable base}, journal = {Proceedings of the 2009 IEEE International Conference on Robotics and Automation (ICRA 2009)}, year = {2009}, month = {5}, pages = {1597-1598}, abstract = {Research on humanoid robots for use in servicing tasks, e.g. fetching and delivery, attracts steadily more interest. With “Rollin' Justin” a mobile robotic system and research platform is presented that allows sophisticated control algorithms and dexterous manipulation. This video gives an overview of the mobile humanoid robotic system “Rollin' Justin” with special emphasis on mechanical design features, control issues and high-level system capabilities such as human robot interaction.}, file_url = {/fileadmin/user_upload/files/publications/ICRA09_1027_FI_[0].pdf}, web_url = {http://www.icra2009.org/}, publisher = {IEEE Service Center}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Robotics and Automation (ICRA '09)}, event_place = {Kobe, Japan}, state = {published}, ISBN = {978-1-4244-2788-8}, DOI = {10.1109/ROBOT.2009.5152586}, author = {Borst C, Wimb\"ock T, Schmidt F, Fuchs M, Brunner B, Zacharias F, Robuffo Giordano P{robu_pa}{Department Human Perception, Cognition and Action}, Konietschke R, Sepp W, Fuchs S, Rink C, Albu-Sch\"affer A and Hirzinger G} } @Inproceedings{ 5818, title = {Does Brief Exposure to a Self-avatar Affect Common Human Behaviors in Immersive Virtual Environments?}, journal = {Eurographics 2009: The 30th Annual Conference of the European Association for Computer Graphics}, year = {2009}, month = {4}, pages = {33-36}, abstract = {A plausible assumption is that self-avatars increase the realism of immersive virtual environments (VEs), because self-avatars provide the user with a visual representation of his/her own body. Consequently having a self-avatar might lead to more realistic human behavior in VEs. To test this hypothesis we compared human behavior in VE with and without providing knowledge about a self-avatar with real human behavior in real-space. This comparison was made for three tasks: a locomotion task (moving through the content of the VE), an object interaction task (interacting with the content of the VE), and a social interaction task (interacting with other social entities within the VE). Surprisingly, we did not find effects of a self-avatar exposure on any of these tasks. However, participant’s VE and real world behavior differed significantly. These results challenge the claim that knowledge about the self-avatar substantially influences natural human behavior in immersive VEs.}, file_url = {/fileadmin/user_upload/files/publications/EG2009_5818[0].pdf}, web_url = {http://www.eurographics2009.de/}, publisher = {European Association for Computer Graphics}, address = {Geneve, Switzerland}, booktitle = {Eurographics 2009}, event_name = {30th Annual Conference of the European Association for Computer Graphics}, event_place = {München, Germany}, state = {published}, author = {Streuber S{stst}{Department Human Perception, Cognition and Action}, de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Trutoiu LC{auract}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Mohler B{mohler}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5624, title = {Computationally efficient techniques for data-driven haptic rendering}, journal = {Proceedings of the World Haptics 2009: Third Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (WHC 2009)}, year = {2009}, month = {3}, pages = {39-44}, abstract = {Data-driven haptic rendering requires processing of raw recorded signals, which leads to high computational effort for large datasets. To achieve real-time performance, one possibility is to reduce the parameter space of the employed interpolation technique, which generally decreases the accuracy in the rendering. In this paper, we propose a method for guiding this parameter reduction to maintain high accuracy with respect to the just noticeable difference for forces. To this end, we performed a user study to estimate this perception threshold. The threshold is used to assess the final error in the rendered forces as well as for the parameter reduction process. Comparison with measured data from real object interactions confirms the accuracy of our method and highlights the reduced computational effort.}, web_url = {http://www.worldhaptics.org/2009/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, booktitle = {World Haptics 2009}, event_name = {Third Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (WHC 2009)}, event_place = {Salt Lake City, UT, USA}, state = {published}, ISBN = {978-1-424-43859-4}, DOI = {10.1109/WHC.2009.4810814}, author = {H\"over R, Di Luca M{max}{Department Human Perception, Cognition and Action}{Research Group Multisensory Perception and Action}, Szekely G and Harders M} } @Inproceedings{ 5876, title = {Tech-note: Iterative design and test of a multimodal experience}, journal = {Proceedings of the IEEE Symposium on 3D User Interfaces (3DUI 2009)}, year = {2009}, month = {3}, pages = {99-102}, abstract = {The goal of the Turtle surf project described in this tech-note is to design, implement and evaluate a multimodal installation that should provide a good user experience in a virtual 3D world. For this purpose we combine audio-visual media forms and different types of haptic/tactile feedback. For the latter, we focus on the application of vibrational feedback, wind and water spray and heat. We follow a user-centered design approach and try to get user feedback as early as possible during the iterative design process. We present the conceptual idea of the Turtle surf project, and the iterative design and test of prototypes that helped us to refine the final design based on collected user feedback.}, web_url = {http://conferences.computer.org/3dui/3dui2009/}, editor = {Kiyokawa, K. , S. Coquillart, R. Balakrishnan}, publisher = {IEEE Service Center}, address = {Piscataway, NJ, USA}, event_name = {IEEE Symposium on 3D User Interfaces (3DUI 2009)}, event_place = {Lafayette, LA, USA}, state = {published}, ISBN = {978-1-424-43966-9}, DOI = {10.1109/3DUI.2009.4811213}, author = {Reckter H, Geiger C, Singer J and Streuber S{stst}{Department Human Perception, Cognition and Action}} } @Inproceedings{ 5628, title = {Effect of lateral motion on drivers‘ performance in the MPI motion simulator}, journal = {Proceedings of the Driving Simulation Conference (DSC-Europe 2009)}, year = {2009}, month = {2}, pages = {121-131}, web_url = {http://www.ctag.com/ver_evento.htm?event_id=15}, event_name = {Driving Simulation Conference Europe (DSC 2009)}, event_place = {Monte Carlo, Monaco}, state = {published}, author = {Pretto P{pretto}{Department Human Perception, Cognition and Action}, Nusseck H-G{nusseck}{Department Human Perception, Cognition and Action}, Teufel H{teufel}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inbook{ 5749, title = {What visual discrimination of fractal textures can tell us about discrimination of camouflaged targets}, year = {2009}, month = {12}, pages = {99-112}, abstract = {Most natural images have 1/fβ Fourier image statistics, a signature which is mimicked by fractals and which forms the basis for recent applications of fractals to camouflage. To distinguish a fractal camouflaged target (with 1/fβ* statistics) from a 1/fβ natural background (or another target), the exponents of target and background (or other target) must differ by a critical amount (dβ=β-β*), which varies depending on experimental circumstances. The same constraint applies for discriminating between friendly and enemy camouflaged targets. Here, we present data for discrimination of both static and dynamic fractal images, and data on how discrimination varies as a function of experimental methods and circumstances. The discrimination function has a minimum near β=1.6, which typifies images with less high spatial frequency content than the vast majority of natural images (β near 1.1). This implies that discrimination between fractal camouflaged objects is somewhat more difficult when the camouflaged objects are sufficiently similar in statistics to the statistics of natural images (as any sensible camouflage scheme should be), compared to the less natural β value of 1.6. This applies regardless of the β value of the background, which has implications for fratricide; friendlies and hostiles will be somewhat harder to tell apart for naturalistically camouflaged images, even when friendlies and hostiles are both visible against their backgrounds. The situation is even more perverse for “active camouflage”. Because of perceptual system nonlinearities (stochastic resonance), addition of dynamic noise to targets can actually enhance target detection and identification under some conditions.}, web_url = {http://www.ashgate.com/isbn/9780754677673}, editor = {Andrews, D. H., T. Hull}, publisher = {Ashgate}, address = {Farnham, UK}, series = {Human Factors in Defense}, booktitle = {Human Factors Issues in Combat Identification}, state = {published}, ISBN = {978-0-7546-9515-8}, author = {Billock VA, Cunningham DW{dwc}{Department Human Perception, Cognition and Action} and Tsou BH} } @Inbook{ 5229, title = {The sensory-motor theory of semantics: Evidence from functional imaging}, year = {2009}, month = {1}, pages = {177-210}, web_url = {http://www.peterlang.com/index.cfm?vID=57630&amp;vLang=D&amp;vHR=1&amp;vUR=2&amp;vUUR=3}, editor = {Fuchs, S. , H. Loevenbruck, D. Pape, P. Perrier}, publisher = {Lang}, address = {Frankfurt (Main), Germany}, booktitle = {Some Aspects of Speech and the Brain}, state = {published}, ISBN = {978-3-631-57630-4}, author = {Noppeney U{unoppe}{Research Group Cognitive Neuroimaging}} } @Techreport{ 5757, title = {Scene scaling during simulated forward accelerations: Are explicit size cues used?}, year = {2009}, month = {1}, number = {182}, file_url = {/fileadmin/user_upload/files/publications/tr-182_5757[0].pdf}, state = {published}, author = {Berger DR{berger}{Department Human Perception, Cognition and Action}} } @Poster{ Bieg2009, title = {Influences of task complexity and individual differences on the performance of gaze-assisted human-machine interfaces}, year = {2009}, month = {11}, volume = {10}, number = {2}, pages = {21}, abstract = {Human-machine interfaces can be enhanced by incorporating knowledge of the user’s current point of regard. For example, Zhai and colle agues (1999) showed that faster task completion times could be achieved on a simple pointing task if the display pointer was translocated according to the user’s gaze. This manipulation removes the need to manually move the pointer and hence, promises time-savings that grows in proportion to display size. Here, we report the findings of applying the same technique on a wall-sized display (2.2m × 1.8 m), across more complex pointing task. Two main components comprised the four tasks that participants were required to perform, with and without gaze-assisted pointing: Namely, conjunctive search of colored shapes and click-and-drag of items to a circumscribed region. Contrary to previous findings, we found that gaze-assisted pointer placement significantly increased task completion times, relative to manual pointer placement. Detailed analyses revealed that task complexity and individual differences in gaze behaviour and eye-hand coordination had an adverse effect on task performance, which emphasizes the importance of considering these factors in future implementations of gaze-assisted interfaces.}, web_url = {http://www.neuroschool-tuebingen-nena.de/}, event_name = {10th Conference of Junior Neuroscientists of Tübingen (NeNa 2009)}, event_place = {Ellwangen, Germany}, state = {published}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}} } @Poster{ 6162, title = {Attention to motion: Differential cortical modulation to forward and planar visual flow}, year = {2009}, month = {10}, volume = {39}, number = {558.21}, abstract = {Self- and object-motion processing greatly relies on visual cues. There are at least two entirely independent kinds of self-induced visual motion that combine to optic flow in the visual field: expansion flow, such as that induced by forward motion in depth, or planar motion, such as induced by translational self-motion or by pursuit eye movements across a visual scene. In real life, both signals may occur in combination, yet, only one of the cues may be of behavioral relevance, thus requiring to be selectively attended to. In this fMRI study we attempt to address the question whether differential neural substrates get modulated by selective attention to either one of these motion cues. We created a stimulus combining an expansion flow pattern with translational motion on the same set of dots. In a feature-based detection task, subjects selectively attended either to the expansion or to the translation component of the stimulus and reported changes in the speed of the attended motion component. In control conditions that used the same stimuli subjects attended to color hue changes of the fixation cross, or passively fixated the stimulus without any attentional demand. In each of the three attention conditions, the attentional load was kept constant across conditions by a continuously updating staircase procedure. We found that attention to expansion modulated the separately localized areas MT/V5, MST, and V3A significantly more than attention to translation. This is in line with stimulus-driven studies that showed a preference to expansion/contraction stimuli in these areas (Smith et al., 2006). In contrast, V7 and the cingulate sulcus visual area (CSv) differed from all other regions, in that they did not show any selective modulation by attention to expansion flow. Most interestingly, we found motion selective modulation in the foveal confluence of V1, despite a physical match between stimulus conditions. This might be due to differential attentional enhancement within V1, or by differential feedback from higher regions such as MT/V5, MST or V3A. Our results therefore show a differential attentional modulation within the motion-processing pathway, depending on the type of motion-component that is attended to within the same flow stimulus. Smith AT, Wall MB, Williams AL, Singh KD (2006) Sensitivity to optic flow in human cortical areas MT and MST.}, web_url = {http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=3b1b2e24-3671-4e3d-9051-5dfbb3c15f6c&cKey=81bf6c91-1c74-4f55-870b-c12dbcb94af7}, event_name = {39th Annual Meeting of the Society for Neuroscience (Neuroscience 2009)}, event_place = {Chicago, IL, USA}, state = {published}, author = {Fischer E{efischer}{Department Physiology of Cognitive Processes}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}, Logothetis NK{nikos}{Department Physiology of Cognitive Processes} and Bartels A{abartels}{Department Physiology of Cognitive Processes}} } @Poster{ 6291, title = {How does the brain identify living things based on their motion?}, year = {2009}, month = {10}, volume = {39}, number = {380.15}, abstract = {Animals (including humans) have to identify living moving things in the environment: these could be prey, enemies or mates and interactions with them should be actively controlled. Living things could be detected visually through their shape or their motion, or both. When shape is hard to see (fog, twilight, great distance, small animal), motion becomes an important cue. Biological motion has been studied widely using point-light displays, but these displays appear to contain some sort of shape or form information that influences recognition. To study the neural correlates of the detection of living entities from motion alone, we developed a stimulus consisting of a single moving dot, thus eliminating all possible sources of information about form, spatial arrangement, shape or structure of the object. Our single dot moved such that it appeared either self-propelled (modelled on the movements of a fly) or moved by an external force (modelled on a leaf drifting in the wind). Both types of movement were built using the same equation but differed in speed and acceleration profiles according to a small set of parameters. Low-level stimulus characteristics of the stimuli (range of positions on the screen, average speed, overall aspect of the trajectory) were kept as constant as possible. The parameters could be varied in a continuous fashion to create morphs between the self-propelled and externally-moved extremes. Consistent with expectations, behavioral experiments showed that self-propelled stimuli were perceived as more animate (= more likely to be alive) than the externally-moved stimuli, with a gradual transition occurring in the intermediary morphs. The extreme stimuli and four intermediary morphs were presented in an fMRI experiment to participants who had to categorize the stimuli into alive and non-alive. Using separate functional localizers, we located areas hMT+/V5 and the superior temporal sulcus region responding to point-light walkers, and found that neither region showed changes in BOLD response following the changes in percept. However, BOLD response in a region of the left posterior superior parietal cortex scaled with the degree of perceived animacy. This suggests that the STS is not simply a detector of all kinds of animate motion, but might only be implicated when some sort of shape information in the stimuli (as with point-light displays or with interacting dots) is contributing to the percept of animacy.}, web_url = {http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=f5dec3fb-2bb6-482d-8553-db756136f1a1&cKey=e2a39a05-441a-496b-8048-e8c4ae6e6a46}, event_name = {39th Annual Meeting of the Society for Neuroscience (Neuroscience 2009)}, event_place = {Chicago, IL, USA}, state = {published}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 5909, title = {The situational influence of location and body orientation on the recall of survey knowledge}, journal = {Cognitive Processes}, year = {2009}, month = {9}, volume = {10}, number = {Supplement 2}, pages = {S169}, abstract = {The theories of situated and embodied cognition have been gaining more and more attention recently. We examined the influence of the current situation (i.e., location and orientation) on accessing spatial memory of locations within ones city of residence. Tu¨bingen residents produced a simple map of the city centre, by arranging small badges representing well-known locations on a sheet of paper or a computer screen. Participants produced the maps at different locations relative to the city centre (north of, east of, etc.) and in different body orientations (facing north, east, etc.). We analyzed the orientation of these maps (north up, east up, etc.).We found an influence of location and body orientation on the orientation of the maps. Participants produced maps in the orientation they were facing more often than expected by chance (i.e., produced a north up map when facing north, an east up map when facing east, etc.). Participants also oriented the maps according to their viewpoint more often than expected by chance (i.e., produced a north up map when located south of the city centre, an east up map when located west, etc.). These results indicate that some participants either selected one of multiple long-term representations or they adopted a single longterm spatial representation according to the current situation.}, web_url = {http://w3.uniroma1.it/icsc/2009/}, event_name = {4th International Conference on Spatial Cognition (ICSC 2009)}, event_place = {Roma, Italy}, state = {published}, DOI = {10.1007/s10339-009-0328-1}, author = {Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Frankenstein J{frankenstein}{Department Human Perception, Cognition and Action}, Holzer S{sholzer}{Department Human Perception, Cognition and Action} and Brescani J-P{bresciani}{Department Human Perception, Cognition and Action}} } @Poster{ SchultzL2009, title = {BOLD signal in intraparietal sulcus covaries with magnitude of implicitly driven attention shifts}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {137}, abstract = {A lot is known about the neural basis of directing attention based on explicit cues. In real life however, attention shifts are rarely directed by explicit cues but rather generated implicitly, for example on the basis of previous experience. Here, we aimed at studying attention shifts dependent on recent trial history. We asked observers to detect targets in a stream of visual stimuli with three feature dimensions: colour, shape and motion. Critically, target occurrence probability was always higher in one stimulus dimension than in the others, and probabilities switched between dimensions over blocks of trials. After each probability switch, target detection times decreased exponentially for high-probability targets and increased for low-probability targets, compatible with gradual shifts in attention dependent on trial history since the switch. BOLD signal in left prefrontal and intraparietal sulcus regions was higher in the early phase after the switch, while anterior cingulate, cuneus, precuneus, temporal and more anterior frontal regions showed more activation later after the switch. These findings are compatible with expectation about engagement of regions involved in the establishment and maintenance of attentional sets. BOLD signal in left intraparietal sulcus correlated with the size of the performance changes consecutive to the detected targets, suggesting that it reflects the size of attention shifts induced by updating target probabilities over recent trial history.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090332}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Schultz J{johannes}{Department Human Perception, Cognition and Action} and Lennert T{lennert}{Department Human Perception, Cognition and Action}} } @Poster{ delaRosaCC2009, title = {Detection, categorization, and identification are separable component processes of object recognition}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {26}, abstract = {Are detection, categorization, and identification of upright images of natural objects mediated by the same or different visual processes? Surprisingly, previous studies found that object detection is as fast as object categorization while object identification takes significantly longer. This suggests that object detection and categorization are mediated by the same visual processes while object identification is mediated by different visual processes (eg Grill-Spector and Kanwisher, 2005 Psychological Science 16(2) 152 - 160). We compared (a) the time course of object detection, categorization, and identification of upright object images using a higher temporal resolution than in previous studies (Experiments 1 and 2); and (b) the sensitivity of these three recognition processes (Experiment 3). Participants saw two consecutive image presentations of which one contained an object image and the other a patch of visual noise. On every trial participants reported the object interval (detection), the object's category (categorization), and the object identity (identification). We measured participants' accuracy to conduct each of these tasks as a function of presentation time (Experiments 1 and 2), and signal-to-noise ratio (Experiment 3). We found significant differences between the psychometric functions of object detection, categorization, and identification in all three experiments. We conclude that detection, categorization, and identification are separable component processes of object recognition.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090030}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {de la Rosa S{delarosa}{Department Human Perception, Cognition and Action}, Choudhery R{choudhery}{Department Human Perception, Cognition and Action} and Chatziastros A{astros}{Department Human Perception, Cognition and Action}} } @Poster{ 5908, title = {Distance and alignment effects in survey knowledge of a highly familiar city}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {63}, abstract = {In this experiment we examined alignment and distance effects in human memory for a highly familiar environmental space. Twenty-seven participants who lived on average seven years in Tübingen saw a photorealistic virtual model of the city centre of Tübingen (Virtual Tübingen) through a head-mounted display. They were teleported to five different places in Virtual Tübingen and asked to point towards well-known target locations. This procedure was repeated 36 times for each of the target locations in 12 different body orientations. Participants pointed much more accurately when oriented northwards regardless of target. There were no significant correlations between straight line distance to the pointing target and pointing speed or accuracy. These results are consistent with the assumption that all locations were represented within one oriented coordinate system. Even though this is predicted by reference direction theory, it is unclear why, first, almost all participants have the same reference direction, and second, why this direction is north. We discuss our results with respect to well-known theories of spatial memory and speculate that the bias for a north orientation is because participants rely on the memory of a map of Tübingen for their response.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090953}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Frankenstein J{frankenstein}{Department Human Perception, Cognition and Action}, Mohler B{mohler}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Meilinger T{meilinger}{Department Human Perception, Cognition and Action}} } @Poster{ 5954, title = {Going beyond universal expressions: investigating the visual perception of dynamic facial expressions}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {83}, abstract = {Investigations of facial expressions have focused almost exclusively on the six so-called universal expressions. During everyday interaction, however, a much larger set of facial expressions is used for communication. To examine this mostly unexplored space, we developed a large video database for emotional and conversational expressions: native German participants performed 58 expressions based on pre-defined context scenarios. Three experiments were performed to investigate the validity of the scenarios and the recognizability of the expressions. In Experiment 1, ten participants were asked to freely name the facial expressions that would be elicited given the scenarios. The scenarios were effective: 82% of the answers matched the intended expressions. In Experiment 2, ten participants had to identify 55 expression videos of ten actors, presented successively. We found that 20 expressions could be identified reliably without any context. Finally, in Experiment 3, twenty participants had to group the 55 expression videos based on similarity while allowing for repeated comparisons. Out of the 55 expressions, 45 formed a consistent group, respectively, showing that visual comparison facilitates the recognition of conversational expressions. Interestingly, none of the experiments found any advantage for the universal expressions, demonstrating the robustness with which we interpret conversational facial expressions.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090219}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Kaulard K{kascot}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action}, Cunningham DW{dwc}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 5867, title = {Head mobility influences gaze behavior across natural viewing tasks}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {166}, abstract = {Natural gaze behavior is often studied under conditions that restrain head movements. Here, we report how the availability of head movement can influence gaze behavior on wall-sized images of natural outdoor scenes (field-of- view: ~90°). Participants performed half of the experiment with complete head mobility and the remaining trials with their heads restrained in a chin-rest. They were required to either rate the images for attractiveness (i.e., free-viewing) or to count the visible animals (i.e., visual search). On average, more fixations were found on the trials that allowed for head movements (unrestrained: 4.21 fixations/sec; restrained: 3.75 fixations/sec), which were also shorter in their mean duration (unrestrained: 221 ms; restrained: 252 ms). In addition, unrestrained gaze contained a larger proportion of small amplitude saccades (i.e., less than 5°), than head-restrained gaze. Finally, our participants demonstrated a general preference in fixating regions that were close to the central eye-in-h ead orientation. Altogether, these findings suggest that the availability of head movements allowed our participants to re-orient to regions of interest and sample these regions more frequently. This sampling benefit applied to both visual search and free viewing tasks. The current findings emphasize the importance of allowing head mobility when studying natural gaze behavior.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090902}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Chuang LL{chuang}{Department Human Perception, Cognition and Action}, Herholz S{sherholz}{Department Human Perception, Cognition and Action}, B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action} and Fleming R{roland}{Department Human Perception, Cognition and Action}} } @Poster{ 6082, title = {Influences of task complexity and individual differences on the performance of gaze-assisted human-machine interfaces}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {172}, abstract = {Human-machine interfaces can be enhanced by incorporating knowledge of the user's current point of regard. For example, Zhai and colleagues (1999) showed that faster task completion times could be achieved on a simple pointing task if the display pointer was translocated according to the user's gaze. This manipulation removes the need to manually move the pointer and hence, promises time-savings that grows in proportion to display size. Here, we report the findings of applying the same technique on a wall-sized display (2.2 m × 1.8 m), across more complex pointing task. Two main components comprised the four tasks that participants were required to perform, with and without gaze-assisted pointing: Namely, conjunctive search of colored shapes and click-and-drag of items to a circumscribed region. Contrary to previous findings, we found that gaze-assisted pointer placement significantly increased task completion times, relative to manual pointer placement. Detailed analyses revealed that task complexity and individual differences in gaze behaviour and eye-hand coordination had an adverse effect on task performance, which emphasizes the importance of considering these factors in future implementations of gaze-assisted interfaces.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090846}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Bieg H-J{bieg}{Department Human Perception, Cognition and Action}, Chuang LL{chuang}{Department Human Perception, Cognition and Action} and Reiterer H} } @Poster{ 5919, title = {Perceptual face space in vision and haptics}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {161}, abstract = {The idea that faces are represented within a high-dimensional vector space has gained considerable experimental support both from physiological and perceptual studies. More generally, recent work has shown that the brain possesses a surprising acuteness in extracting such high-dimensional spaces from both visual and haptic stimuli. Here, we investigate the degree to which visual and haptic face spaces might be similar. For this, we created a face space consisting of 6 laser-scanned individual faces, their morphed average, 50%-morphs between two individual faces, as well as 50%-morphs of individual faces with the average, resulting in a set of 19 faces. We then gathered either visual or haptic pairwise similarity ratings of 3-D face masks from two groups of fifteen participants. Faces were explored 6 s visually, and 10 s haptically with one hand, respectively. Correlations between haptic similarity ratings were lower than between visual ones indicating the difficulty of the haptic task. Importantly, however, multidimensional scaling analyses showed that both modalities preserved critical topological relationships of the original space in a 3-D perceptual space. Our data demonstrates how the brain can extract high-dimensional shape properties of complex stimuli in both vision and haptics.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090746}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Wallraven C{walli}{Department Human Perception, Cognition and Action}} } @Poster{ 5710, title = {Place naming: examining the influence of language on wayfinding}, year = {2009}, month = {8}, volume = {31}, pages = {1997}, abstract = {We asked the question how language influences a presumably embodied system such as human wayfinding. To test this, participants walked along a route in a virtual environment. They were asked to remember half of the intersections by what they saw. At the other 50% of intersections they heard an arbitrary name which they also had to remember. In the test phase they were teleported to different intersections and had to indicate the direction the route went on. At intersections without a name they performed faster and more accurately. In a second experiment meaningful names were used instead. Participants now performed better at named intersection. The results indicate an interaction between language and the presumably embodied wayfinding system. This interaction cannot be explained by a limited common resource, depth of processing, overshadowing, or linguistic scaffolding. However, it is consistent with dual coding.}, web_url = {http://cognitivesciencesociety.org/conference2009/index.html}, event_name = {31st Annual Conference of the Cognitive Science Society (CogSci 2009)}, event_place = {Amsterdam, Netherlands}, state = {published}, author = {Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Schulte-Pelkum J{jsp}{Department Human Perception, Cognition and Action}, Frankenstein J{frankenstein}{Department Human Perception, Cognition and Action}, Laharnar N{naima}{Department Human Perception, Cognition and Action}, Hardie{\ss} G, Mallot HA{ham}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ 6312, title = {Prediction by the human visual system: Extrapolation of complex curves}, journal = {Journal of Vision}, year = {2009}, month = {8}, volume = {9}, number = {8}, pages = {910}, abstract = {Successful prediction may be the main objective of any cognitive system. We investigate how humans solve the underconstrained problem of spatial extrapolation of complex 2D curves. Contour continuation problems are usually modeled based on local variational principles such as minimizing total curvature or variation of curvature and have only been applied to a very limited set of curves classes. Singh&Fulvio (2006) showed that only a probabilistic model of these constraints can explain the continuation of arcs of Euler spirals. We investigate whether the same model generalizes to more complex curves such as polynomials or regular curves, how much higher-order information is used and how the extrapolation is influenced by the experimental design. Subjects report either the position of a single curve dot behind a semi-circular occluder or draw the distribution of possible extrapolants. Our results show that subjects report multiple curves for more complex curves if they are given the chance (e.g., by drawing distributions or by probability matching). We approach the extrapolation problem from a more global Bayesian perspective and show that the results are more consistent with Bayesian model averaging rather than purely local models.}, web_url = {http://www.journalofvision.org/9/8/910/}, event_name = {9th Annual Meeting of the Vision Sciences Society (VSS 2009)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/9.8.910}, author = {Tanner TG{tanner}{Department Human Perception, Cognition and Action}} } @Poster{ 6311, title = {Probabilistic extrapolation of complex curves}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {52}, abstract = {I investigate how humans solve the underconstrained problem of spatial extrapolation of complex 2-D curves. Contour continuation is typically modeled using local variational principles such as minimizing total curvature or variation of curvature and have only been applied to a very limited set of curves classes. Singh and Fulvio (2006) showed that only a probabilistic model of these constraints can explain the continuation of arcs of Euler spirals. I investigate whether this model generalizes to more complex curves such as polynomials or regular curves, how much higher-order information is used, and how the extrapolation is influenced by the experimental design. Subjects report either the position of a single curve dot behind a semi-circular occluder or draw the distribution of possible extrapolants. Results show that subjects report multiple extrapolants for more complex curves if they are given the opportunity (by drawing multimodal distributions or by probability matching). I model the results with Bayesia n model averaging, and show that this explains the data better than a static model. This suggests that observers do not use a fixed extrapolation scheme but can also adapt to the context, taking into account the complexity of the visible portion of the curve.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090979}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Tanner TG{tanner}{Department Human Perception, Cognition and Action}} } @Poster{ 5918, title = {Re-learning face recognition: evidence for efficient strategies without holistic processing}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {100}, abstract = {In previous experiments, we showed an advantage for visual over haptic face recognition. Promoting serial encoding in vision using a novel gaze-restricted display, we found that these differences are due to modality-specific encoding strategies (holistic in vision vs serial in haptics), and that serial encoding leads to featural (vs holistic) processing. Here, we test how the observed encoding and processing differences might be affected by expertise. Participants were trained on five consecutive days on a set of 19 faces using an old/new recognition task for which three faces were learned with feedback, followed by four test-blocks. On days 1 (pre-test), 4 (post-test), and 5, the task consisted of two upright and two inverted test-blocks. On day 5, we tested participants on a different set of faces. Performance for upright faces was low on day 1, but improved significantly through training ( d1'=1.11, d4'=3.75). Importantly, this learning effect generalized to a new face-set on day 5 ( d5'=3.07). Although performance significantly improved through training, we found no inversion effect on any day ( d1'=1.70, d4'=3.54) indicating no change in processing strategies. Our results show that participants can develop efficient, generalizing strategies to compensate for encoding differences, and that these strategies do not require holistic encoding.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090145}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Dopjans L{ldopjans}{Department Human Perception, Cognition and Action}, Wallraven C{walli}{Department Human Perception, Cognition and Action} and B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ Bulthoff2009, title = {Sex categorization is influenced by facial information about identity}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {78}, abstract = {According to Bruce and Young's (1986 British Journal of Psychology 77 305 - 327) classic model of face recognition, sex-related information about a face is accessed independently of information about identity. Therefore familiarity with a face should not influence sex categorization. This issue of independence has remained controversial as it has been supported in some studies and questioned in others. Here we used faces that were presented in two conditions: sex-unchanged and sex-changed. Participants were very familiar with some of the identities. For all participants, the unchanged familiar faces presented congruent identity and sex information while the sex-changed familiar faces presented incongruent identity and sex information. Participants performed a sex categorization task on all familiar and unfamiliar faces presented in the unchanged and sex-changed condition. They were asked to ignore identity and base their responses solely on the sex appearance of the faces. Our results show that participants were slower and less correct for sex-changed than for unchanged familiar faces while those differences did not appear for unfamiliar faces. These results indicate that sex and identity are not independent as participants could not ignore identity information while doing a sex categorization task.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090132}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {B\"ulthoff I{isa}{Department Human Perception, Cognition and Action}} } @Poster{ HoltmannRiceF2009, title = {Shape from smear}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {28}, abstract = {Recent work indicates that the patterns of scales and orientations in an image ('orientation fields') may play an important role in 3-D shape perception. If true, it should be possible to elicit percepts of specific 3-D shapes using stimuli containing only an appropriate orientation field. To investigate this, we use line-integral convolution to 'smear (coerce) 2-D noise patterns to have a geometrically 'correct' orientation field (ie, as similar as possible to the orientation field present in the rendering of some object). The spatial scales are also modulated to be physically accurate. Importantly, the image generation process is entirely based on 2-D filtering operations, and is fundamentally different from a physically realistic rendering. Despite this, the resulting pattern elicits almost as vivid an impression of the object's 3-D shape as a true rendering. Such images were used in depth comparison and gauge figure tasks to assess the relative contribution of spatial scales and orientation fields to shape perception; as well as the dramatic breakdown of shape perception resulting from physically unrealistic orientation and scale configurations. By examining the accuracy with which subjects are able to make metric judgments (relative depth and surface orientation) about the shape percepts evoked by these patterns, we demonstrate that the continuous variations of orientation and spatial scale across an image can play a key role in 3-D shape inference.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090727}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Holtmann-Rice DN{dhr}{Department Human Perception, Cognition and Action} and Fleming RW{roland}{Department Human Perception, Cognition and Action}} } @Poster{ 5907, title = {The influence of the current situation on the recall of survey knowledge: the case of location and body orientation}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {66}, abstract = {Theories of situated and embodied cognition have been gaining more and more attention recently. We examined the influence of the current situation (ie, location and orientation) on accessing spatial memory of locations within one's city of residence. Tübingen residents produced a simple map of the city centre, by arranging small badges representing well-known locations on a sheet of paper. Participants produced the maps at different locations relative to the city centre (north of, east of, etc) and in different body orientations (facing north, east, etc). We analyzed the orientation of these maps (north up, east up, etc). We found an influence of location and body orientation on the orientation of the maps. Participants produced maps in the orientation they were facing more often than expected by chance (eg, produced an east up map when facing east). Participants also oriented the maps according to their viewpoint more often than expected by chance (eg, produced a west up map when located east of the city centre). These results indicate that participants do not just access spatial long-term memory of their city of residence, but that they adjust it according to their current situation.}, web_url = {http://www.perceptionweb.com/abstract.cgi?id=v090730}, event_name = {32nd European Conference on Visual Perception}, event_place = {Regensburg, Germany}, state = {published}, author = {Meilinger T{meilinger}{Department Human Perception, Cognition and Action}, Frankenstein J{frankenstein}{Department Human Perception, Cognition and Action}, Holzer S{sholzer}{Department Human Perception, Cognition and Action} and Brescani J-P} } @Poster{ Streuberd2009, title = {The role of body and tool-based information in joint action coordination}, journal = {Perception}, year = {2009}, month = {8}, volume = {38}, number = {ECVP Abstract Supplement}, pages = {33}, abstract = {Influential theories (eg common coding theory) suggest that visual body information about the interaction partner is critical when two people physically interact (joint action). Evidence supporting this idea comes from studies investigating computer mediated joint actions. Surprisingly, this hypothesis has not been examined in a real-life joint action task. To test this hypothesis, participants cooperatively played table tennis in complete darkness with the ball, net, and table illuminated with fluorescent markings (Experiment 1). In different conditions we added different types of visual information by placing glowing point markers on the players' body (body information) and/or marking the paddle's rim with fluorescent paint (tool information). We found a significantly reduced error rate when body and/or tool information was available. In Experiment 2 the same types of visual information were available to only one player at a time. The error rate was measured in every condition for each player separately. We found improved performance when the player saw his/her own body or the other player's tool but not when he/she saw his/her own tool or the other player's body. These findings challeng