@Proceedings{ TrutoiuGKSM2015, title = {ACM SIGGRAPH Symposium on Applied Perception}, year = {2015}, month = {9}, pages = {139}, abstract = {It is our pleasure to present the proceedings of the ACM Symposium on Applied Perception (SAP) held at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, September 13-14, 2015. SAP, formerly known as APGV, aims to advance and promote research that crosses the boundaries between perception and disciplines such as graphics, visualization and vision. Our twelfth annual event includes exciting new research from all of these disciplines. As is customary for SAP, conferences held in odd years are typically hosted in Europe.}, web_url = {http://dl.acm.org/citation.cfm?id=2804408}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {ACM SIGGRAPH Symposium on Applied Perception (SAP '15)}, event_place = {Tübingen, Germany}, state = {published}, ISBN = {978-1-4503-3812-7}, author = {Trutoiu L{auract}; Geuss M{mgeuss}{Department Human Perception, Cognition and Action}; Kuhl S; Sanders B; Mantiuk R} } @Article{ GeussMS2016, title = {Fear Similarly Alters Perceptual Estimates of and Actions over Gaps}, journal = {PLoS ONE}, year = {2016}, month = {7}, volume = {11}, number = {7}, pages = {1-19}, abstract = {Previous research has demonstrated an influence of one’s emotional state on estimates of spatial layout. For example, estimates of heights are larger when the viewer is someone typically afraid of heights (trait fear) or someone who, in the moment, is experiencing elevated levels of fear (state fear). Embodied perception theories have suggested that such a change in perception occurs in order to alter future actions in a manner that reduces the likelihood of injury. However, other work has argued that when acting, it is important to have access to an accurate perception of space and that a change in conscious perception does not necessitate a change in action. No one has yet investigated emotional state, perceptual estimates, and action performance in a single paradigm. The goal of the current paper was to investigate whether fear influences perceptual estimates and action measures similarly or in a dissociable manner. In the current work, participants either estimated gap widths (Experiment 1) or were asked to step over gaps (Experiment 2) in a virtual environment. To induce fear, the gaps were placed at various heights up to 15 meters. Results showed an increase in gap width estimates as participants indicated experiencing more fear. The increase in gap estimates was mirrored in participants’ stepping behavior in Experiment 2; participants stepped over fewer gaps when experiencing higher state and trait fear and, when participants actually stepped, they stepped farther over gap widths when experiencing more fear. The magnitude of the influence of fear on both perception and action were also remarkably similar (5.3 and 3.9 cm, respectively). These results lend support to embodied perception claims by demonstrating an influence on action of a similar magnitude as seen on estimates of gap widths.}, web_url = {http://journals.plos.org/plosone/article/asset?id=10.1371%2Fjournal.pone.0158610.PDF}, state = {published}, DOI = {10.1371/journal.pone.0158610}, EPUB = {e0158610}, author = {Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}; McCardell MJ; Stefanucci JK{jstefanucci}{Department Human Perception, Cognition and Action}} } @Article{ GeussSCTM2015, title = {Effect of Display Technology on Perceived Scale of Space}, journal = {Human Factors}, year = {2015}, month = {11}, volume = {57}, number = {7}, pages = {1235-1247}, abstract = {Objective: Our goal was to evaluate the degree to which display technologies influence the perception of size in an image. Background: Research suggests that factors such as whether an image is displayed stereoscopically, whether a user’s viewpoint is tracked, and the field of view of a given display can affect users’ perception of scale in the displayed image. Method: Participants directly estimated the size of a gap by matching the distance between their hands to the gap width and judged their ability to pass unimpeded through the gap in one of five common implementations of three display technologies (two head-mounted displays [HMD] and a back-projection screen). Results: Both measures of gap width were similar for the two HMD conditions and the back projection with stereo and tracking. For the displays without tracking, stereo and monocular conditions differed from each other, with monocular viewing showing underestimation of size. Conclusions: Display technologies that are capable of stereoscopic display and tracking of the user’s viewpoint are beneficial as perceived size does not differ from real-world estimates. Evaluations of different display technologies are necessary as display conditions vary and the availability of different display technologies continues to grow. Applications: The findings are important to those using display technologies for research, commercial, and training purposes when it is important for the displayed image to be perceived at an intended scale.}, web_url = {http://hfs.sagepub.com/content/57/7/1235.full.pdf+html}, state = {published}, DOI = {10.1177/0018720815590300}, author = {Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}; Stefanucci JK{jstefanucci}{Department Human Perception, Cognition and Action}; Creem-Regehr SH; Thompson WB; Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Article{ GagnonGSBC2015, title = {The influence of social context and body size on action judgments for self and others}, journal = {Journal of Experimental Psychology: Human Perception and Performance}, year = {2015}, month = {10}, volume = {41}, number = {5}, pages = {1385-1395}, abstract = {Judgments of affordances, the potential actions that an observer can carry out within an environment, require observers to relate information about their body to information in the environment. Although humans can accurately judge affordances for others, it is unknown whether other people’s capability to act influences one’s own affordance judgments. Based on theoretical accounts and recent empirical evidence highlighting the importance of social information in perception and action, we hypothesized that the action capabilities of another person would influence one’s own affordance judgments. Participants judged their own and another’s ability to pass through an aperture in 3 experiments that varied the differences in body sizes between the participant and another agent using naturally occurring body size differences or an artificial large body suit. Results showed an influence of the other’s body size on self-affordance judgments only when the participant and the other agent remained in their natural body size (Experiment 3), but not when the body size differences between the participant and the other agent were extreme because of the body suit (Experiments 1 and 2).}, web_url = {http://psycnet.apa.org/journals/xhp/41/5/1385.pdf}, state = {published}, DOI = {10.1037/xhp0000089}, author = {Gagnon KT; Geuss MN{mgeuss}; Stefanucci JK{jstefanucci}; Baucom BR; Creem-Regehr SH} } @Article{ StefanucciCTLG2015, title = {Evaluating the accuracy of size perception on screen-based displays: Displayed objects appear smaller than real objects}, journal = {Journal of Experimental Psychology: Applied}, year = {2015}, month = {9}, volume = {21}, number = {3}, pages = {215-223}, abstract = {Accurate perception of the size of objects in computer-generated imagery is important for a growing number of applications that rely on absolute scale, such as medical visualization and architecture. Addressing this problem requires both the development of effective evaluation methods and an understanding of what visual information might contribute to differences between virtual displays and the real world. In the current study, we use 2 affordance judgments—perceived graspability of an object or reaching through an aperture—to compare size perception in high-fidelity graphical models presented on a large screen display to the real world. Our goals were to establish the use of perceived affordances within spaces near to the observer for evaluating computer graphics and to assess whether the graphical displays were perceived similarly to the real world. We varied the nature of the affordance task and whether or not the display enabled stereo presentation. We found that judgments of grasping and reaching through can be made effectively with screen-based displays. The affordance judgments revealed that sizes were perceived as smaller than in the real world. However, this difference was reduced when stereo viewing was enabled or when the virtual display was viewed before the real world.}, web_url = {http://psycnet.apa.org/journals/xap/21/3/215.pdf}, state = {published}, DOI = {10.1037/xap0000051}, author = {Stefanucci JK{jstefanucci}{Department Human Perception, Cognition and Action}; Creem-Regehr SH; Thompson WB; Lessard DA; Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}} } @Article{ ButnerGGLS2014, title = {Utilizing Topology to Generate and Test Theories of Change}, journal = {Psychological Methods}, year = {2015}, month = {3}, volume = {20}, number = {1}, pages = {1-25}, abstract = {Statistical and methodological innovations in the study of change are advancing rapidly, and visual tools have become an important component in model building and testing. Graphical representations such as path diagrams are necessary, but may be insufficient in the case of complex theories and models. Topology is a visual tool that connects theory and testable equations believed to capture the theorized patterns of change. Although some prior work has made use of topologies, these representations have often been generated as a result of the tested models. This article argues that utilizing topology a priori, when developing a theory, and applying analogous statistical models is a prudent method to conduct research. This article reviews topology by demonstrating how to build a topological representation of a theory and recover the implied equations, ultimately facilitating the transition from complex theory to testable model. Finally, topologies can guide researchers as they adjust or expand their theories in light of recent model testing.}, web_url = {http://psycnet.apa.org/journals/met/20/1/1.pdf}, state = {published}, DOI = {10.1037/a0037802}, author = {Butner JE; Gagnon KT; Geuss MN{mgeuss}; Lessard DA; Story TN} } @Article{ LinkenaugerPMCBSGW2014, title = {The Perceptual Homunculus: The Perception of the Relative Proportions of the Human Body}, journal = {Journal of Experimental Psychology: General}, year = {2015}, month = {2}, volume = {144}, number = {1}, pages = {103-113}, abstract = {Given that observing one’s body is ubiquitous in experience, it is natural to assume that people accurately perceive the relative sizes of their body parts. This assumption is mistaken. In a series of studies, we show that there are dramatic systematic distortions in the perception of bodily proportions, as assessed by visual estimation tasks, where participants were asked to compare the lengths of two body parts. These distortions are not evident when participants estimate the extent of a body part relative to a noncorporeal object or when asked to estimate noncorporal objects that are the same length as their body parts. Our results reveal a radical asymmetry in the perception of corporeal and noncorporeal relative size estimates. Our findings also suggest that people visually perceive the relative size of their body parts as a function of each part’s relative tactile sensitivity and physical size.}, web_url = {http://psycnet.apa.org/journals/xge/144/1/103.pdf}, state = {published}, DOI = {10.1037/xge0000028}, author = {Linkenauger SA{sally}{Department Human Perception, Cognition and Action}; Wong Hy; Geuss M{mgeuss}{Department Human Perception, Cognition and Action}; Stefanucci JK{jstefanucci}{Department Human Perception, Cognition and Action}; McCulloch KC; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Mohler BJ{mohler}{Department Human Perception, Cognition and Action}; Proffitt DR} } @Article{ LinkenaugerGSLRPBM2014, title = {Evidence for Hand-Size Constancy: The Dominant Hand as a Natural Perceptual Metric}, journal = {Psychological Science}, year = {2014}, month = {11}, volume = {25}, number = {11}, pages = {2086-2094}, abstract = {The hand is a reliable and ecologically useful perceptual ruler that can be used to scale the sizes of close, manipulatable objects in the world in a manner similar to the way in which eye height is used to scale the heights of objects on the ground plane. Certain objects are perceived proportionally to the size of the hand, and as a result, changes in the relationship between the sizes of objects in the world and the size of the hand are attributed to changes in object size rather than hand size. To illustrate this notion, we provide evidence from several experiments showing that people perceive their dominant hand as less magnified than other body parts or objects when these items are subjected to the same degree of magnification. These findings suggest that the hand is perceived as having a more constant size and, consequently, can serve as a reliable metric with which to measure objects of commensurate size.}, web_url = {http://pss.sagepub.com/content/25/11/2086.full.pdf+html}, state = {published}, DOI = {10.1177/0956797614548875}, author = {Linkenauger SA{sally}{Department Human Perception, Cognition and Action}; Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}; Stefanucci JK{jstefanucci}{Department Human Perception, Cognition and Action}; Leyrer M{leyrer}{Department Human Perception, Cognition and Action}; Richardson BH; Proffitt DR; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Article{ CreemRegehrGGS2013, title = {Relating spatial perspective taking to the perception of other's affordances: providing a foundation for predicting the future behavior of others}, journal = {Frontiers in Human Neuroscience}, year = {2013}, month = {9}, volume = {7}, number = {596}, pages = {1-14}, abstract = {Understanding what another agent can see relates functionally to the understanding of what they can do. We propose that spatial perspective taking and perceiving other's affordances, while two separate spatial processes, together share the common social function of predicting the behavior of others. Perceiving the action capabilities of others allows for a common understanding of how agents may act together. The ability to take another's perspective focuses an understanding of action goals so that more precise understanding of intentions may result. This review presents an analysis of these complementary abilities, both in terms of the frames of reference and the proposed sensorimotor mechanisms involved. Together, we argue for the importance of reconsidering the role of basic spatial processes to explain more complex behaviors.}, web_url = {http://journal.frontiersin.org/Journal/10.3389/fnhum.2013.00596/pdf}, state = {published}, DOI = {10.3389/fnhum.2013.00596}, author = {Creem-Regehr SH; Gagnon KT; Geuss MN{mgeuss}; Stefanucci JK{jstefanucci}} } @Article{ gagnonGS2013, title = {Fear influences perceived reaching to targets in audition, but not vision}, journal = {Evolution and Human Behavior}, year = {2013}, month = {1}, volume = {34}, number = {1}, pages = {49–54}, abstract = {The superordinate mechanism view of emotions predicts that fear should influence perception to carry out the evolved function of overcoming immediate threats. Previous work demonstrates that fear does adaptively influence visual perception. However, there are recurring situations in which auditory perception is used for overcoming immediate threats (e.g., avoiding predators after dark). Some research suggests that the auditory system, independent of fear, is adaptively biased to hear approaching sounds as closer than equidistant receding sounds (a.k.a. the looming bias). The present study investigated whether fear, as a superordinate mechanism, influences auditory perception such that sounds are perceived to be closer, ultimately providing an advantage when avoiding immediate threats. Participants judged whether or not they could reach to an aurally or visually perceived target while either in a fearful or neutral state. The results demonstrated that while in a fearful state, participants judged targets to be closer to them, but only when the target was perceived aurally. This finding extends previous work on adaptive biases in auditory perception to include the influence of fear.}, web_url = {http://www.sciencedirect.com/science/article/pii/S1090513812000918}, state = {published}, DOI = {10.1016/j.evolhumbehav.2012.09.002}, author = {Gagnon KT; Geuss MN{mgeuss}; Stefanucci JK{jstefanucci}} } @Article{ GeussSCT2012, title = {Effect of viewing plane on perceived distances in real and virtual environments}, journal = {Journal of Experimental Psychology: Human Perception and Performance}, year = {2012}, month = {10}, volume = {38}, number = {5}, pages = {1242-1253}, abstract = {Three experiments examined perceived absolute distance in a head-mounted display virtual environment (HMD-VE) and a matched real-world environment, as a function of the type and orientation of the distance viewed. In Experiment 1, participants turned and walked, without vision, a distance to match the viewed interval for both egocentric (viewer-to-target) and exocentric (target-to-target) extents. Egocentric distances were underestimated in the HMD-VE while exocentric distances were estimated similarly across environments. Since egocentric distances were displayed in the depth plane and exocentric distances in the frontal plane, the pattern of results could have been related to the orientation of the distance or to the type of distance. Experiments 2 and 3 tested these alternatives. Participants estimated exocentric distances presented along the depth or frontal plane either by turning and walking (Experiment 2) or by turning and throwing a beanbag to indicate the perceived extent (Experiment 3). For both Experiments 2 and 3, depth intervals were underestimated in the HMD-VE compared to the real world. However, frontal intervals were estimated similarly across environments. The findings suggest anisotropy in HMD-VE distance perception such that distance underestimation in the HMD-VE generalizes to intervals in the depth plane, but not to intervals in the frontal plane.}, web_url = {http://psycnet.apa.org/journals/xhp/38/5/1242.pdf}, state = {published}, DOI = {10.1037/a0027524}, author = {Geuss MN{mgeuss}; Stefanucci JK{jstefanucci}; Creem-Regehr SH; Thompson WB} } @Article{ GeussSdS2010, title = {A balancing act: Physical balance, through arousal, influences size perception}, journal = {Attention, Perception, & Psychophysics}, year = {2010}, month = {10}, volume = {72}, number = {7}, pages = {1890-1902}, abstract = {Previous research has demonstrated that manipulating vision influences balance. Here, we question whether manipulating balance can influence vision and how it may influence vision—specifically, the perception of width. In Experiment 1, participants estimated the width of beams while balanced and unbalanced. When unbalanced, participants judged the widths to be smaller. One possible explanation is that unbalanced participants did not view the stimulus as long as when balanced because they were focused on remaining balanced. In Experiment 2, we tested this notion by limiting viewing time. Experiment 2 replicated the findings of Experiment 1, but viewing time had no effect on width judgments. In Experiment 3, participants’ level of arousal was manipulated, because the balancing task likely produced arousal. While jogging, participants judged the beams to be smaller. In Experiment 4, participants completed another arousing task (counting backward by sevens) that did not involve movement. Again, participants judged the beams to be smaller when aroused. Experiment 5A raised participants’ level of arousal before estimating the board widths (to control for potential dual-task effects) and showed that heightened arousal still influenced perceived width of the boards. Collectively, heightened levels of arousal, caused by multiple manipulations (including balance), influenced perceived width.}, web_url = {http://link.springer.com/content/pdf/10.3758%2FAPP.72.7.1890.pdf}, state = {published}, DOI = {10.3758/APP.72.7.1890}, author = {Geuss MN{mgeuss}; Stefanucci JK{jstefanucci}; de Benedictis-Kessner J; Stevens NR} } @Article{ StefanucciG2010, title = {Duck! Scaling the height of a horizontal barrier to body height}, journal = {Attention, Perception, & Psychophysics}, year = {2010}, month = {7}, volume = {72}, number = {5}, pages = {1338-1349}, abstract = {Recent research shows that the body is used to scale environmental extents. We question whether the body is used to scale heights as measured by real actions (Experiments 1 and 2) or by judgments about action and extent made from a single viewpoint (Experiments 3 and 4). First, participants walked under barriers naturally, when wearing shoes, or when wearing a helmet. Participants required a larger margin of safety (they ducked at shorter heights) when they were made taller. In follow-up experiments, participants visually matched barrier heights and judged whether they could walk under them when wearing shoes or a helmet. Only the helmet decreased visually matched estimates; action judgments were no different when participants’ eye height increased. The final experiment suggested that the change in matched estimates may have been due to lack of experience wearing the helmet. Overall, the results suggest that perceived height is scaled to the body and that when body height is altered, experience may moderate the rescaling of height.}, web_url = {http://link.springer.com/content/pdf/10.3758%2FAPP.72.5.1338.pdf}, state = {published}, DOI = {10.3758/APP.72.5.1338}, author = {Stefanucci JK{jstefanucci}; Geuss MN{mgeuss}} } @Article{ StefanucciG2009, title = {Big people, little world: The body influences size perception}, journal = {Perception}, year = {2009}, month = {12}, volume = {38}, number = {12}, pages = {1782-1795}, abstract = {Previous research has shown that changes to the body can influence the perception of distances in near space (Witt et al, 2005 Journal of Experimental Psychology: Human Perception and Performance 31 880 – 888). In this paper, we question whether changes to the body can also influence the perception of extents in extrapersonal space, namely the perception of aperture widths. In experiment 1, broad-shouldered participants visually estimated the size of apertures to be smaller than narrow-shouldered participants. In experiment 2, we questioned whether changes to the body, which included holding a large object, wearing a large object, or simply holding out the arms would influence perceived width. Surprisingly, we found that only when participants’ hands were widened was extrapersonal space rescaled. In experiment 3, we explored the boundaries of the effect observed in experiment 2 by asking participants to hold their arms at four different positions in order to determine the arm width at which apertures appeared smaller. We found that arm positions that were larger than the shoulder width made apertures appear smaller. The results suggest that dimensions of the body play a role in the scaling of environmental parameters in extrapersonal space.}, web_url = {http://www.perceptionweb.com/perception/fulltext/p38/p6437.pdf}, state = {published}, DOI = {10.1068/p6437}, author = {Stefanucci JK{jstefanucci}; Geuss MN{mgeuss}} } @Inproceedings{ GeussRS2015, title = {Anxiety alters visual guidance of braking over time}, year = {2015}, month = {9}, pages = {241-242}, abstract = {Previous research suggests that drivers use specific visual information to execute braking behaviors [Faj05] and that drivers calibrate braking behavior to this visual information over time [Faj09]. Specifically, Fajen (2005) argued that when successfully braking, participants adjust braking pressure to maintain a visually-specified ideal braking pressure less than one’s maximum ability to brake. In the current paper, we investigated whether factors, specifically one’s emotional state, would alter the relationship between braking behavior and visually-specified ideal braking pressure over time. Specifically, we investigated whether the performance of braking changed when anxious. Previous research demonstrated that anxiety influences static perceptual judgments of space [Gra12] and the performance of open-loop sports actions [Bei10]. Open-loop actions are actions where once the movement has been initiated there are no opportunities to alter the outcome (i.e., putting a golf ball). This research shows an influence of anxiety on static perceptual tasks and the performance of open-loop actions suggesting that anxiety may also influence more complex everyday actions like braking. It is important to know whether, and how, the influence of anxiety extends to the performance of closedloop actions like braking given the potential realworld consequences of poor performance.}, web_url = {http://dsc2015.tuebingen.mpg.de/Program.html}, editor = {Bülthoff, H.H. , A. Kemeny, P. Pretto}, publisher = {Max Planck Institute for Biological Cybernetics}, address = {Tübingen, Germany}, event_name = {DSC 2015 Europe: Driving Simulation Conference & Exhibition}, event_place = {Tübingen, Germany}, state = {published}, ISBN = {978-3-9813099-3-5}, author = {Geuss M{mgeuss}{Department Human Perception, Cognition and Action}; Ruginski IT; Stefanucci JK{jstefanucci}{Department Human Perception, Cognition and Action}} } @Inproceedings{ JunSCGT2015, title = {Big Foot: Using the Size of a Virtual Foot to Scale Gap Width}, journal = {ACM Transactions on Applied Perception}, year = {2015}, month = {9}, volume = {12}, number = {4:16}, pages = {1-16}, abstract = {Spatial perception research in the real world and in virtual environments suggests that the body (e.g., hands) plays a role in the perception of the scale of the world. However, little research has closely examined how varying the size of virtual body parts may influence judgments of action capabilities and spatial layout. Here, we questioned whether changing the size of virtual feet would affect judgments of stepping over and estimates of the width of a gap. Participants viewed their disembodied virtual feet as small or large and judged both their ability to step over a gap and the size of gaps shown in the virtual world. Foot size affected both affordance judgments and size estimates such that those with enlarged virtual feet estimated they could step over larger gaps and that the extent of the gap was smaller. Shrunken feet led to the perception of a reduced ability to step over a gap and smaller estimates of width. The results suggest that people use their visually perceived foot size to scale virtual spaces. Regardless of foot size, participants felt that they owned the feet rendered in the virtual world. Seeing disembodied, but motion-tracked, virtual feet affected spatial judgments, suggesting that the presentation of a single tracked body part is sufficient to produce similar effects on perception, as has been observed with the presence of fully co-located virtual self-avatars or other body parts in the past.}, web_url = {http://sap.acm.org/2015/schedule.php}, editor = {Trutoiu, L. , M. Geuss, S Kull, B. Sanders, R. Mantiuk}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {ACM SIGGRAPH Symposium on Applied Perception (SAP '15)}, event_place = {Tübingen, Germany}, state = {published}, DOI = {10.1145/2811266}, author = {Jun E; Stefanucci JK{jstefanucci}{Department Human Perception, Cognition and Action}; Creem-Regehr SH; Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}; Thompson WB} } @Inproceedings{ WellerdiekBGSKBM2015, title = {Perception of Strength and Power of Realistic Male Characters}, year = {2015}, month = {9}, pages = {7-14}, abstract = {We investigated the influence of body shape and pose on the perception of physical strength and social power for male virtual characters. In the first experiment, participants judged the physical strength of varying body shapes, derived from a statistical 3D body model. Based on these ratings, we determined three body shapes (weak, average, and strong) and animated them with a set of power poses for the second experiment. Participants rated how strong or powerful they perceived virtual characters of varying body shapes that were displayed in different poses. Our results show that perception of physical strength was mainly driven by the shape of the body. However, the social attribute of power was influenced by an interaction between pose and shape. Specifically, the effect of pose on power ratings was greater for weak body shapes. These results demonstrate that a character with a weak shape can be perceived as more powerful when in a high-power pose.}, file_url = {fileadmin/user_upload/files/publications/2015/SAP-2015-Wellerdiek.pdf}, web_url = {http://dl.acm.org/citation.cfm?id=2804413}, editor = {Trutoiu, L. , M. Geuss, S Kull, B. Sanders, R. Mantiuk}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {ACM SIGGRAPH Symposium on Applied Perception (SAP '15)}, event_place = {Tübingen, Germany}, state = {published}, ISBN = {978-1-4503-3812-7}, DOI = {10.1145/2804408.2804413}, author = {Wellerdiek AC{awellerdiek}{Department Human Perception, Cognition and Action}; Breidt M{mbreidt}{Department Human Perception, Cognition and Action}; Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}; Streuber S{stst}{Department Human Perception, Cognition and Action}; Kloos U; Black MJ; Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Inproceedings{ GutekunstGSKM2014, title = {A Video Self-avatar Influences the Perception of Heights in an Augmented Reality Oculus Rift}, year = {2014}, month = {12}, day = {9}, pages = {9-12}, abstract = {This paper compares the influence a video self-avatar and a lack of a visual representation of a body have on height estimation when standing at a virtual visual cliff. A height estimation experiment was conducted using a custom augmented reality Oculus Rift hardware and software prototype also described in this paper. The results show a consistency with previous research demonstrating that the presence of a visual body influences height estimates, just as it has been shown to influence distance estimates and affordance estimates.}, web_url = {http://diglib.eg.org/handle/10.2312/ve.20141358.009-012}, editor = {Nojima, T. , D. Reiners, O. Staadt}, publisher = {Eurographics Association}, address = {Aire-la-Ville, Switzerland}, event_name = {International Conference on Artificial Reality and Telexistence, 19th Eurographics Symposium on Virtual Environments (ICAT-EGVE 2014)}, event_place = {Bremen, Germany}, state = {published}, ISBN = {978-3-905674-65-1}, DOI = {10.2312/ve.20141358}, author = {Gutekunst M; Geuss M{mgeuss}{Department Human Perception, Cognition and Action}; Rauhoeft G{grauhoeft}{Department Human Perception, Cognition and Action}; Stefanucci JK{jstefanucci}{Department Human Perception, Cognition and Action}; Kloos U; Mohler B{mohler}{Department Human Perception, Cognition and Action}} } @Inproceedings{ TarampiGSC2014, title = {A Preliminary Study on the Role of Movement Imagery in Spatial Perception}, year = {2014}, month = {9}, pages = {383-395}, abstract = {According to dance theory, dancers are uniquely aware of the relationship between the environment and their body, making them a type of spatial expert. Inherent in their practice are the abilities to assess the location of other people, objects and the environment relative to their body, and to use movement imagery. The current study tests if dancers perceive the world differently than non-dancers. To test this, dancers performed a battery of spatial tasks (egocentric and exocentric distance estimates, a height judgment, and affordance judgments, i.e., perceived vertical and horizontal passability, stepability, and jumpability) and completed paper-and-pencil spatial ability tests. Dancers differed from non-dancers in their movement imagery ability but superior imagery ability did not result in greater accuracy in imagined distance estimates. Height judgments were overestimated in both groups but less so in dancers. Dancers were found to be, on average, less conservative in their affordance judgments than non-dancers.}, web_url = {http://link.springer.com/content/pdf/10.1007%2F978-3-319-11215-2_27.pdf}, editor = {Freksa, C. , B. Nebel, M. Hegarty, T. Barkowsky}, publisher = {Springer}, address = {Berlin, Germany}, series = {Lecture Notes in Computer Science ; 8684}, booktitle = {Spatial Cognition IX}, event_name = {Spatial Cognition 2014}, event_place = {Bremen, Germany}, state = {published}, ISBN = {978-3-319-11214-5}, DOI = {10.1007/978-3-319-11215-2_27}, author = {Tarampi MR; Geuss MN{mgeuss}; Stefanucci JK{jstefanucci}; Creem-Regehr SH} } @Inproceedings{ StefanucciLGCT2012, title = {Evaluating the accuracy of size perception in real and virtual environments}, year = {2012}, month = {8}, pages = {79-82}, abstract = {Accurate perception of the size of 3D objects depicted on 2D desktop displays is important for many applications. Whether users perceive objects depicted on a display to be the same size as comparable real world objects is not well understood. We propose using affordances judgments as a way of measuring the perceived size of objects depicted in desktop virtual environments and the real world. The methodology involves indicating whether or not a particular action can be performed in a given environment, making it a flexible measure that can be used across different display technologies. In two studies, we test users’ perceptions of size by asking them to make affordance judgments in both the real world and a geometrically matched desktop virtual environment. In the first study, users judge whether they can grasp an object and in the second study, they judge whether they can fit their hand through an opening. In both experiments we show that users perceive the size of objects in the desktop virtual environment to be smaller than in the real world.}, file_url = {fileadmin/user_upload/files/publications/2012/SAP-2012-Stefanucci.pdf}, web_url = {http://dl.acm.org/citation.cfm?id=2338692&CFID=595083652&CFTOKEN=12884097}, editor = {Khooshabeh, P. , M. Harders, R. McDonnell, V. Sundstedt}, publisher = {ACM Press}, address = {New York, NY, USA}, event_name = {ACM Symposium on Applied Perception (SAP '12)}, event_place = {Los Angeles, CA, USA}, state = {published}, ISBN = {978-1-4503-1431-2}, DOI = {10.1145/2338676.2338692}, author = {Stefanucci JK{jstefanucci}; Lessard DA; Geuss MN{mgeuss}; Creem-Regehr SH; Thompson W} } @Inproceedings{ GeussSCT2010, title = {Can I pass?: Using affordances to measure perceived size in virtual environments}, year = {2010}, month = {7}, pages = {61-64}, abstract = {Perception of an accurate sense of the scale depicted in computer graphics is important for many applications. How to best characterize the accuracy of space perception in computer graphics is a question that does not have a simple answer. This paper describes the use of perceived affordances as a way of measuring the perceptual fidelity of virtual environments with respect to how well they convey information about geometric scale. The methodology involves a verbal indication that a particular action can or cannot be performed in a viewed environment. By varying the spatial structure of the environment, these affordance judgments can be used to probe how accurately viewers are able to perceive action-relevant spatial information. The result is a measure relevant to action, less subject to bias than verbal reports of more primitive properties such as size or distance, and applicable to non-virtual-environment display systems in which the actual action cannot be performed. We demonstrate the approach in an experiment comparing one type of affordance judgment, perceived passability, with judgments of size and distance in matched real world and virtual world environments.}, file_url = {fileadmin/user_upload/files/publications/APGV-2010-Geuss.pdf}, web_url = {http://dl.acm.org/citation.cfm?id=1836259&CFID=595083652&CFTOKEN=12884097}, 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 = {10.1145/1836248.1836259}, author = {Geuss M{mgeuss}; Stefanucci J{jstefanucci}; Creem-Regehr S; Thompson WB} } @Poster{ ThalerPGSdSRBM2017, title = {Gender differences in visual perception of own body weight}, year = {2017}, month = {8}, day = {29}, web_url = {http://www.ecvp.org/2017/programme.html}, event_name = {40th European Conference on Visual Perception (ECVP 2017)}, event_place = {Berlin, Germany}, state = {published}, author = {Thaler A{athaler}{Department Human Perception, Cognition and Action}; Piryankova I{ivelina}{Department Human Perception, Cognition and Action}; Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}; Stefanucci JK{jstefanucci}{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}; Romero J{jromero}; Black MJ{black}; Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ ThomasGRS2017, title = {Braking bad: Arousal influences the visual guidance of braking}, journal = {Journal of Vision}, year = {2017}, month = {8}, volume = {17}, number = {10}, pages = {994}, abstract = {Arousal has been shown to influence perceptual judgments as well as the execution of online motor control (e.g., as in the case of choking under pressure). The current study investigated whether arousal also influences the online control of a common visually-guided action over time. Participants performed either an emergency (Experiment 1) or regulated (Experiment 2) braking task with the goal of stopping before colliding with a target. For the emergency braking task, participants applied maximum braking pressure and once braking pressure was applied it could not be released. For regulated braking, participants were able to adjust braking pressure as needed over time. Participants performed one braking task after arousal induction or not. We were primarily interested in testing the hypothesis of whether arousal altered the calibration between visual information and action execution. We hypothesized that arousal would indeed act as a soft constraint on motor control (Harrison, Frank, & Turvey, 2016). Behaviorally, we hypothesized that arousal would lead to faster initiation of braking and less crashing, by influencing the perceptual-motor calibration of braking with respect to visual information. Results from emergency braking supported our hypotheses — anxious participants initiated braking sooner and crashed less often. However, when performing regulated braking, anxious participants initiated braking sooner but crashed more often. Overall, the results demonstrated that participants were more conservative in their braking, but that this actually led to a greater chance of crashing when braking was continuously regulated because of their greater reliance on current braking. These results imply that emotions act to alter the calibration between perception and action. Future work may benefit from integrating continuous, physiological indicators of emotional states. }, web_url = {http://www.visionsciences.org/programs/VSS_2017_Abstracts.pdf}, event_name = {17th Annual Meeting of the Vision Sciences Society (VSS 2017)}, event_place = {St. Pete Beach, FL, USA}, state = {published}, DOI = {10.1167/17.10.994}, author = {Thomas B; Geuss M{mgeuss}{Department Human Perception, Cognition and Action}; Ruginski I; Stefanucci J{jsefanucci}} } @Poster{ ThalerGSMGBM2017, title = {Perception of others’ body sizes is predicted by own body size}, journal = {Journal of Vision}, year = {2017}, month = {8}, volume = {17}, number = {10}, pages = {843}, abstract = {Previous research demonstrated that estimates of others’ body sizes are biased towards the average body size in the population (Cornelissen, Gledhill, Cornelissen & Tovée, 2016). Bodies in the environment not only influence the internal reference of what is perceived as average or “normal”, but also play an essential role in self-body size evaluation via social comparison (Cattarin, Thompson, Thomas & Williams, 2000). In two psychophysical experiments, we asked whether there is also an influence of own body size on the perception of others’ body sizes. For Experiment 1, four biometric female avatars with a body mass index (BMI) of 15, 25, 35, and 45 were generated, and then their weight was altered (± 5, ±10, ±15, and ±20% BMI change) based on a statistical body model. For each of the avatar series, female participants spanning the BMI range memorized what the avatar’s body looked like and then responded for the presented bodies varying in weight whether it was the same as the one memorized. Results showed no influence of participants’ BMI on the accuracy of body size estimates, but sensitivity to weight changes was highest for bodies close to one’s own BMI. In Experiment 2, we examined whether this effect was driven by memory or perceptual factors. Specifically, in a 2-alternative forced choice discrimination task, two bodies were presented simultaneously using the same BMI categories as in Experiment 1. If participants’ body size influences sensitivity during simultaneous presentation, it would suggest that the effect found in Experiment 1 is not due to a better memorization of bodies that are close to one’s own body size. Again, sensitivity to differences in body weight was highest for bodies close to one’s own BMI. These results suggest that our own body size influences our perceptual ability to discriminate the sizes of other’s bodies.}, web_url = {http://www.visionsciences.org/programs/VSS_2017_Abstracts.pdf}, event_name = {17th Annual Meeting of the Vision Sciences Society (VSS 2017)}, event_place = {St. Pete Beach, FL, USA}, state = {published}, DOI = {10.1167/17.10.843}, author = {Thaler A{athaler}; Geuss M{mgeuss}; Stefanucci J{jstefanucci}; M\"olbert S{smoelbert}; Giel K; Black M{black}; Mohler B{mohler}} } @Poster{ GeussMTM2016, title = {Body size estimations: the role of visual information from a first-person and mirror perspective}, journal = {Journal of Vision}, year = {2016}, month = {9}, volume = {16}, number = {12}, pages = {986}, abstract = {Our perception of our body, and its size, is important for many aspects of everyday life. Using a variety of measures, previous research demonstrated that people typically overestimate the size of their bodies (Longo & Haggard, 2010). Given that self-body size perception is informed from many different experiences, it is surprising that people do not perceive their bodies veridically. Here, we asked, whether different visual experiences of our bodies influence how large we estimate our body’s size. Specifically, participants estimated the width of four different body parts (feet, hips, shoulders, and head) as well as a noncorporeal object with No Visual Access, Self-Observation (1st person visual access), or looking through a Mirror (2nd person visual access) using a visual matching task. If estimates when given visual access (through mirror or 1st person perspective) differ from estimates made with no visual access, it would suggest that this method of viewing one’s body has less influence on how we represent the size of our bodies. Consistent with previous research, results demonstrated that in all conditions, each body part was overestimated. Interestingly, in the No Visual Access and Mirror conditions, the degree of overestimation was larger for upper body parts compared to lower body parts and there were no significant differences between the No Visual Access and Mirror conditions. There was, however, a significant difference between the Self-Observation condition and the other two conditions when estimating ones shoulder width. In the Self-Observation condition, participants were more accurate with estimating shoulder width. The similarity of results in the No Visual Access and Mirror conditions suggests that our representation of our body size may be partly based on experiences viewing one’s body in reflective surfaces.}, web_url = {jov.arvojournals.org/article.aspx?articleid=2550960}, event_name = {16th Annual Meeting of the Vision Sciences Society (VSS 2016)}, event_place = {St. Pete Beach, FL, USA}, state = {published}, DOI = {10.1167/16.12.986}, author = {Geuss M{mgeuss}{Department Human Perception, Cognition and Action}; M\"olbert SC{smoelbert}; Thaler A{athaler}{Department Human Perception, Cognition and Action}; Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ ThalerGMGBM2016, title = {Does Sensitivity to Weight Changes of Others Depend on Personal Body Size?}, year = {2016}, month = {9}, pages = {28}, abstract = {Previous research has suggested that size estimates of bodies (own and others') are biased towards an average reference body (Cornelissen et al., 2015; Cornelissen et al., 2016). The role of personal body size in body size perception of others is still unclear. In this study, we tested healthy females varying in body mass index (BMI) to investigate whether personal body size influenced accuracy of body size estimation and sensitivity to weight changes of others. We generated four biometric female avatars with BMIs of 15, 25, 35, and 45 and altered the weight of the avatars (5, 10, 15, and 20).}, web_url = {https://sites.google.com/site/nenaconference/nena-2016}, event_name = {17th Conference of Junior Neuroscientists of Tübingen (NeNa 2016): Neuroscience & Law}, event_place = {Schramberg, Germany}, state = {published}, author = {Thaler A{athaler}; Geuss MN{mgeuss}; M\"olbert SC{smoelbert}; Giel KE; Black MJ{black}; Mohler BJ{mohler}} } @Poster{ ThalerGMGSBM2016, title = {Investigating the influence of personal BMI on own body size perception in females using self-avatars}, journal = {Journal of Vision}, year = {2016}, month = {9}, volume = {16}, number = {12}, pages = {1400}, abstract = {Previous research has suggested that inaccuracies in own body size estimation can largely be explained by a known error in perceived magnitude, called contraction bias (Cornelissen, Bester, Cairns, Tovée & Cornelissen, 2015). According to this, own body size estimation is biased towards an average reference body, such that individuals with a low body mass index (BMI) should overestimate their body size and high BMI individuals should underestimate their body size. However, previous studies have mainly focused on self-body size evaluation of patients suffering from anorexia nervosa. In this study, we tested healthy females varying in BMI to investigate whether personal body size influences accuracy of body size estimation and sensitivity to weight changes, reproducing a scenario of standing in front of a full length mirror. We created personalized avatars with a 4D full-body scanning system that records participants’ body geometry and texture, and altered the weight of the avatars based on a statistical body model. In two psychophysical experiments, we presented the stimuli on a stereoscopic, large-screen immersive display, and asked participants to respond to whether the body they saw was their own. Additionally, we used several questionnaires to assess participants’ self-esteem, eating behavior, and their attitudes towards their body shape and weight. Our results show that participants, across the range of BMI, veridically perceived their own body size, contrary to what is suggested by the contraction bias hypothesis. Interestingly, we found that BMI influenced sensitivity to weight changes in the positive direction, such that people with higher BMIs were more willing to accept bigger bodies as their own. BMI did not influence sensitivity to weight changes in the negative direction.}, web_url = {jov.arvojournals.org/article.aspx?articleid=2551372}, event_name = {16th Annual Meeting of the Vision Sciences Society (VSS 2016)}, event_place = {St. Pete Beach, FL, USA}, state = {published}, DOI = {10.1167/16.12.1400}, author = {Thaler A{athaler}{Department Human Perception, Cognition and Action}; Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}; M\"olbert SC{smoelbert}; Giel KE; Streuber S{stst}{Department Human Perception, Cognition and Action}; Black MJ{black}; Mohler BJ{mohler}{Department Human Perception, Cognition and Action}} } @Poster{ ThalerGMSGBM2016, title = {Sensitivity to Weight Changes of Others Depends on Personal Body Size}, journal = {Perception}, year = {2016}, month = {8}, day = {29}, volume = {45}, number = {ECVP Abstract Supplement}, pages = {53-54}, abstract = {Previous research has suggested that own body size estimates are biased towards an average reference body (Cornelissen, Bester, Cairns, Tove´e & Cornelissen, 2015). The role of personal body size in body size perception of others is still unclear. In this study, we tested healthy females varying in body mass index (BMI) to investigate whether personal body size influenced accuracy of body size estimation and sensitivity to weight changes of others. We generated four biometric female avatars with BMIs of 15, 25, 35, and 45 and altered the weight of the avatars (5, 10, 15, and 20% BMI change) based on a statistical body model. In several psychophysical experiments, we presented the stimuli on a stereoscopic, large-screen immersive display. For each avatar series, participants memorized what the original body looked like and then responded for each of the presented bodies whether it was the same as the one memorized. Our results show that there was no influence of personal BMI on the accuracy of body size estimation of the avatars. Interestingly however, participants were more sensitive to weight changes of an avatar close in BMI to their own, suggesting that own body size influences perception of others’ weight.}, web_url = {http://journals.sagepub.com/doi/full/10.1177/0301006616671273}, event_name = {39th European Conference on Visual Perception (ECVP 2016)}, event_place = {Barcelona, Spain}, state = {published}, DOI = {10.1177/0301006616671273}, author = {Thaler A{athaler}; Geuss MN{mgeuss}; M\"olbert SC{smoelbert}; Streuber S{stst}; Giel KE; Black MJ{black}; Mohler BJ{mohler}} } @Poster{ GeussS2015, title = {Height Estimates Are Altered by State- and Trait-Levels of Fear}, year = {2015}, month = {3}, day = {15}, pages = {3}, abstract = {Fear is characterized by both state- and trait-level changes, both of which can temporally fluctuate to alter behavior. We observed an interaction between state and trait fear on perceptual estimates over time. When trait fear was low, estimates increased with state fear. High trait fear led to consistent overestimation.}, web_url = {http://www.psychologicalscience.org/convention/icps_program/pdf/Poster-Session-III.pdf}, event_name = {International Convention of Psychological Science (ICPS 2015)}, event_place = {Amsterdam, The Netherlands}, state = {published}, author = {Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}; Stefanucci J{jstefanucci}{Department Human Perception, Cognition and Action}} } @Poster{ TannerRuginskiGS2014, title = {Braking Bad: The Dynamic Influence of Anxiety on Visually Guided Action Performance}, journal = {Abstracts of the Psychonomic Society}, year = {2014}, month = {11}, day = {20}, volume = {19}, pages = {81}, abstract = {Previous research shows that emotions can influence perception, but it is unclear whether changes in emotion also alter actions. In the current study we tested whether performance of a braking task (see Fajen, 2008) was altered when anxious. We hypothesized that anxiety would 1) lead to poor braking performance and 2) that changes in braking performance would be due to differences in the visual information that individuals utilized to guide braking. Results indicated that when anxious the margin of error for braking decreased, and that the size of the target may have been used to control braking rather than more optimal visual information (Fajen, 2008). Thus, individuals utilize visual information differently when anxious, which may lead to poorer performance of actions.}, file_url = {fileadmin/user_upload/files/publications/2014/Ann-Meet-Psychon-Soc-2014-55-Ruginski.pdf}, web_url = {http://c.ymcdn.com/sites/www.psychonomic.org/resource/resmgr/Annual_Meeting/Past_and_Future_Meetings/2014/PS_2014_Abstract_Book.pdf}, event_name = {55th Annual Meeting of the Psychonomic Society}, event_place = {Long Beach, CA, USA}, state = {published}, author = {Ruginski I; Geuss MN{mgeuss}; Stefanucci JK{jstefanucci}} } @Poster{ GeussLSCT2012, title = {A comparison of size perception in real and virtual environments using judgments of action capability}, journal = {Journal of Vision}, year = {2012}, month = {8}, volume = {12}, number = {9}, pages = {912}, abstract = {3D scenes are often presented as pictures on desktop monitors. Much of the work on size perception in pictures has used measures involving visual matching. How observers perceive pictorial displays with respect to body-based judgments about action capabilities has not been examined, and may be relevant for applications intended to display act-on-able objects or environments such as in architectural design. Affordance judgments have been used in real and immersive environments, often focused on larger scale actions such as judgments of passage. Here, we use judgments of the ability to grasp a cube to test size perception on a computer desktop display. In the real environment, participants viewed the cubes on a table. In the graphics display, participants viewed a rendering of the same cubes and table on a desktop display. In both conditions, cubes were placed 50 cm and 70 cm from the participant. The cubes were viewed binocularly from a viewpoint location that matched the rendering location. Results were analyzed as a ratio of judged over actual ability. Results revealed a main effect of viewing environment. Participants in the desktop display judged that they could pick up larger cubes than when in the real environment. There was also an interaction of viewing environment and location. The effect of distance was greater in the desktop condition than the real environment. The desktop results are consistent with the size-distance invariance hypothesis, modified by the presumption that distance perception in pictures is affected by both the pictorial cues for distance and the distance of the screen. The real world results show that in the absence of a screen, the judgments are conservative and are minimally affected by distance to the objects. Work is underway to confirm these results with a reaching through measure.}, web_url = {http://jov.arvojournals.org/article.aspx?articleid=2141559}, event_name = {12th Annual Meeting of the Vision Sciences Society (VSS 2012)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/12.9.912}, author = {Geuss M{mgeuss}; Lessard D; Stefanucci J{jstefanucci}; Creem-Regehr S; Thompson W} } @Poster{ ButnerGGMKS2012, title = {Form Perception through Phase Relations of Retina Ganglion Cell Firing and Extraocular Muscle Contractions}, journal = {Journal of Vision}, year = {2012}, month = {8}, volume = {12}, number = {9}, pages = {508}, abstract = {We propose a way of understanding form perception that emphasizes the changes in eye movements relative to changes in firing on the retina; a critical ratio is formed between the frequency of retina ganglion cell firing and the frequency of extraocular muscle contractions (i.e., the muscles controlling eye movements). In Experiment 1 we asked if changes in eye movement frequencies would alter perceived forms and their perceived movement by altering the critical ratio between eye movement and retinal firing frequencies. We manipulated participants’ eye movements by spinning them around in a chair (Jacobson & Shepard, 2007). Participants judged whether a repeating complex dot pattern appeared the same before and after being spun. Twenty-six out of twenty-seven participants reported drastic changes in the image after being spun, suggesting the importance of eye movements in form perception. In Experiment 2, we examined whether critical ratios varied in stability for perceptions of form consistent with a phase locking formula (i.e., Farey sequence). According to the Farey sequence, the most stable ratio is 1:1, where the eye movement frequency and the retinal firing frequency are the same followed by 1:2, 1:3 and so forth following a specific hierarchy of ratios. Participants identified forms in an image, then adjusted the frames per second (fps) at which the image was displayed until they no longer saw the same form. The initial fps of the image was varied to create different critical ratios. Stability was defined as the range of fps for which participants indicated seeing the same form. The results revealed an increase in the stability of the form perceived by participants as the stability of the critical ratio also increased. Together, these experiments suggest that the perception of form is related to the critical ratio formed between retinal firing frequencies and extraocular muscle contraction frequencies.}, web_url = {http://jov.arvojournals.org/article.aspx?articleid=2141155}, event_name = {12th Annual Meeting of the Vision Sciences Society (VSS 2012)}, event_place = {Naples, FL, USA}, state = {published}, DOI = {10.1167/12.9.508}, author = {Butner J; Gagnon K; Geuss M{mgeuss}; Malloy T; Kramer M; Stefanucci J{jstefanucci}} } @Poster{ StefanucciCGGT2017, title = {Real and virtual changes to the body affect the perception of affordances}, journal = {Cognitive Processing}, year = {2012}, month = {8}, volume = {13}, number = {Supplement 1}, pages = {S10}, web_url = {http://link.springer.com/content/pdf/10.1007%2Fs10339-012-0510-8.pdf}, event_name = {Fifth International Conference on Spatial Cognition (ICSC 2012)}, event_place = {Roma, Italy}, state = {published}, DOI = {10.1007/s10339-012-0510-8}, author = {Stefanucci J{jstefanucci}; Creem-Regehr S; Geuss M{mgeuss}; Gagnon K; Thompson W} } @Conference{ GeussCM2016, title = {Judging Affordances From Other Viewpoints: A Role of Perspective Taking?}, journal = {Abstracts of the Psychonomic Society}, year = {2016}, month = {11}, day = {19}, volume = {21}, pages = {56-57}, abstract = {Perspective taking and judging affordances share similar functional goals when determining whether an action is possible from a location dislocated from one’s current viewpoint. We tested the relationship between the two by measuring reaching affordances made from imagined locations around a table. We manipulated imagined self-location, target distance, and presence and length of an avatar arm, using an immersive virtual environment. First, in conditions without an avatar arm, we aimed to establish a baseline for reaching affordance judgments made from other perspectives, and include a novel assessment of response time for affordance judgments. Second, by manipulating visual arm length, we asked whether a change in body capabilities would influence affordance judgments from perspectives other than one’s own, suggesting a role for embodied perspective taking. Initial results suggest that reaching affordances were overestimated more from one’s physical location compared to imagined locations and response time varied with imagined location and distance of target.}, web_url = {http://c.ymcdn.com/sites/www.psychonomic.org/resource/resmgr/annual_meeting/2016_meeting/2016-PS-Abstract-Book.pdf}, event_name = {57th Annual Meeting of the Psychonomic Society}, event_place = {Boston, MA, USA}, state = {published}, author = {Geuss MN{mgeuss}; Creem-Regehr SH; Mohler BJ{mohler}} } @Conference{ GeussDS2013, title = {The Dynamic Relationship Between Fear and Estimates of Virtual Heights}, journal = {Abstracts of the Psychonomic Society}, year = {2013}, month = {11}, day = {17}, volume = {18}, pages = {60}, abstract = {Previous research has demonstrated that fear increases height estimates (Jackson, 2009; Stefanucci & Proffitt, 2009). Given that the intensity of height fear dissipates with time (Emmelkamp et al., 2002), we assessed whether height estimates also changed according to fear levels within and across trials. Participants estimated multiple virtual heights of varying depths by performing a visual matching task. Objective (electrodermal) and subjective (self-report) measures of emotion were employed. Across trials, we assessed whether overestimation of height was attenuated as fear habituated. Within trials, we tested whether the emotional reaction to the displayed height influenced the process of estimation by recording adjustments for the matching task over time. Height estimates decreased across trials, but the rate of decline in estimates was moderated by individuals’ subjective and objective levels of fear. Lower levels of fear were associated with a greater decline in height estimates across trials and different adjustment processes within trials.}, web_url = {http://c.ymcdn.com/sites/www.psychonomic.org/resource/resmgr/Annual_Meeting/Past_and_Future_Meetings/2013/PS_2013_Abstract_Book_WEB_%281.pdf}, event_name = {54th Annual Meeting of the Psychonomic Society}, event_place = {Toronto, Canada}, state = {published}, author = {Geuss MN{mgeuss}{Department Human Perception, Cognition and Action}; Du Toit FD{fdutoit}{Department Human Perception, Cognition and Action}; Stefanucci JK{jstefanucci}{Department Human Perception, Cognition and Action}} } @Conference{ StefanucciGGC2013, title = {The Role of the Body in Perceiving Real and Virtual Spaces}, year = {2013}, month = {6}, volume = {13241}, pages = {56-57}, abstract = {Our work investigates the perception of the body and space in real and virtual environments with the aim of determining whether observers view virtual environments as intended by designers. Using measures adopted from embodied perception theories in psychology, which emphasize the role of the body in space perception, we test whether observers perceive virtual spaces akin to real spaces in the context of body capabilities for action. In immersive virtual environments (IVEs) and real environments, we changed either the physical (real world) or virtual body to assess its influence on whether or not people said they could pass through or under an aperture. IVEs allowed for body manipulations that were not possible in the real world. We found that when the body was made wider or taller through physical manipulations in the real world, people’s estimates of passing through or under an aperture were altered along with their judgments of the width or height of the aperture. We also found that judgments of the ability to pass under or through an aperture were similar across real and virtual environments even when no changes to the body were implemented. Finally, we showed that virtual manipulations of body dimensions (some not possible in the real world) affected decisions about action with respect to apertures in IVEs. Overall, the findings suggest that the body plays a role in space perception in both real and virtual environments, suggesting that care should be taken when constructing virtual representations of the body, especially in the case of self avatars.}, web_url = {http://www.dagstuhl.de/de/programm/kalender/semhp/?semnr=13241}, event_name = {Dagstuhl Seminar 13241: Virtual Realities}, event_place = {Dagstuhl, Germany}, state = {published}, author = {Stefanucci J{jstefanucci}{Department Human Perception, Cognition and Action}; Geuss M{mgeuss}{Department Human Perception, Cognition and Action}; Gagnon K; Creem-Regehr S} }