Self-Motion Perception and Simulation

I lead the Motion Perception and Simulation research group and I am scientific leader for the Wahrnehmungsbasierte Bewegungssimulation (WABS) Research project.

In my research I investigate how different sensory and cognitive factors are involved in efficient human navigation. On the perception side, I study how (I) scene contrast and visual field extent, (II) angular retinal velocities of fixated target and (III) absolute size of viewed objects are used to estimate the speed of self motion. On the simulation side, I mainly focus on driving tasks in order to maximize realistic feedback for effective self-motion simulation. (I) I measure tilt perceptual thresholds to determine the sensation of realism, (II) I tune motion cueing parameters for driving simulators and (III) I contribute to the implementation of human perception-based models into motion cueing algorithms.

For my research I use the Panolab and its immersive virtual environments technology to display scenarios with a high level of visual realism. In addition, I use the CyberMotion Simulator to test different motion configurations in dynamic simulations. Psychophysical adaptive methods and behavioral experiments are carried out to measure self-motion perception and production respectively.

Scene contrast and visual field

The perceived speed of a moving grating can illusorily drop when the visual contrast between the grating and the background is reduced. Yet, the same perceptual process is held responsible for the vehicle accidents occurring in fog, caused by people who drive too fast for the poor visual conditions. The current understanding of this dangerous behavior is, indeed, that driving speed is underestimated in fog, leading drivers to drive faster. However, the question remains whether traditionally adopted depth-independent contrast reduction and more realistic depth-dependent contrast reduction, like fog, produce the same perceptual and behavioral effects. This project aims to broaden the understanding of perceptual processes in real-world situations by considering the relation between contrast attenuation and its distribution in depth.

Other authors: Jean-Pierre Bresciani

Angular-to-linear speed transformation

During translations over a plane at constant speed, the angular retinal speed varies according to where we look at, and still self-linear speed is perceived as constant which allows the world to appear stable. We study factors involved in the retinal-to-linear compensation mechanism, when keeping the eyes static and when tracking a target on the plane, with regard to the growing literature about inverted structure-from-motion mechanisms.

Other authors: Manuel Vidal

Absolute size of viewed objects

Size cues are known to affect the perceived distance between objects. If the physical distance between two objects remains constant, the larger the retinal image of the objects is, the closer to one another they are perceived to be. We test whether top-down size cues affect also the perceived visual speed of self-motion.

Other authors: Jean-Pierre Bresciani

Roll rate thresholds and perceived realism in driving simulation

Active driving simulation provides a variety of visual and vestibular cues as well as demands on attention which vary with task difficulty. It is thus important to measure vestibular perceptual thresholds in conditions that closely resemble typical driving simulation to determine how different sensory and cognitive factors contribute to the sensation of realistic driving. Knowing the relative contribution of these components will lead to more optimized simulated driving.

Other authors: Alessandro Nesti, Michael Barnett-Cowan

MOVES - High-performance motion cueing for driving simulators

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 certain characteristics of 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 scale factors on the perception of motion and on actual driving performance. This work is part of a European collaborative project to explore different motion scale factors in a simple slalom driving task, using three different state-of-the-art simulator systems with displacements of several meters.

WABS - Perception-based motion simulation

The traditional approach to motion simulation is based on the idea that real motion should be exactly reproduced by simulators. However, in many cases the generated motion fails to provide the correct sensation and in extreme cases the discrepancy can lead to motion sickness. The problem does not lie in the technical capabilities of the simulators, but rather on the fact that current approaches focus only on the fidelity of physical motion.

The new perception-based motion simulation approach aims to bring the impression of generated motion as close as possible to reality by implementing psychophysical laws of perception into the control framework of the simulators. Human motion perception models will then be experimentally tested in driving and flying scenarios using the CyberMotion Simulator in order enable a new generation of highly effective motion simulators.

More about WABS

Education

• 2002 M.Sc. in Psychology (University of Padova)
• 2008 Binational PhD in Perception and Psychophysics (University of Padova and University of Tübingen)

Professional experience

• 2002-2003 Research internship at ELASIS S.C.p.A Research Center (FIAT Automobiles)
• 2008-2011 Research Scientist at Max Planck Institute for Biological Cybernetics
• 2012-present Project Leader of the Motion Perception in Vehicle Simulation research group at the Max Planck Insitute for Biological Cybernetics

Awards

• 2002 Prize for M. Sc. Thesis of relevant automotive interest awarded by ATA (“Associazione Tecnica dell’Automobile”), Torino, Italy
• 2003 Post-graduate scholarship, awarded by ELASIS S.C.p.A. Research Center, Italy
• 2004 3-years Doctorate fellowship awarded by Dept. of General Psychology, University of Padua, Italy (ranked first)