Self-motion perception is explored in several different ways at the Max Planck Institute for Biological Cybernetics. First, the perception of self-motion while moving through a space is investigated from a multi-sensory integration perspective looking at the contributions of visual, vestibular, and proprioceptive information. A second focus is on investigations of the illusion of self-motion - that is, how can we fool the user into believing that they are moving without having expensive technology to actually move them. Finally, self-motion perception during walking is studied with the specific aim of better simulating walking within an infinite plane through the development and testing of an omni-directional treadmill.

◘ Human locomotion and gait parameters
◘ Perception of self-motion in Virtual Reality
◘ Spatial updating during movement in two and three dimensions
◘ Perception and production of speed during self-motion
◘ Bayesian integration of visual and vestibular information
◘ Vection in a Large Screen Immersive Virtual Environment
◘ Vestibular Direction Detection Thresholds in the Horizontal Plane

Human Locomotion and gait parameters

Does visual motion influence locomotion? Since many actions are guided primarily by vision one must also consider how vision influences locomotion behavior in a VE. It is possible that information from visual motion is coupled to the metabolic and mechanical information for the speed of self-motion for more reliable, consistent and accurate locomotor behavior. Visual speed was found to affect both the speed of the gait transitions and the speed of free walking (Mohler-EBR 2007). From an engineering viewpoint, this immediate change in behaviors as a result of vision (without user awareness) could be used as a tool when designing VEs. In addition to this prior work, recently the gait parameters for a person who is walking with eyes open versus eyes closed and wearing a head-mounted display versus in the real world was measured. There were two main findings from these results. First, people walk more slowly when their eyes are closed and when they are wearing a head-mounted display (HMD) and a backpack than they do when they are walking in the real world and are unrestricted. Second, when people have a HMD on and are looking at the visuals their head-trunk angle is significantly higher than in all other conditions for the same task (Mohler-EGVE, 2007).

REFERENCES
◘ Mohler, B. J., W. B. Thompson, S. H. Creem-Regehr, H. L. Pick, Jr, and W. H. Warren: Visual flow influences gait transition speed and preferred walking speed. Exp Brain Res. 181(2), 1-16 (08 2007)

◘ Mohler, B. J., J. Campos, M. Weyel and H. H. Bülthoff: Gait parameters while walking in a head-mounted display virtual environment and the real world. Eurographics 2007, 85-88 (07/15/2007)

◘ Mohler, B. J., J. L. Campos, M. B. Weyel and H. H. Bülthoff: Gait parameter differences within an HMD as compared to the real world. 10th Tübinger Wahrnehmungskonferenz (TWK2007) 10, 1 (07 2007)

Full body motion tracking (Vicon)
used to determine differences
between walking in the real and
the head-mounted display virtual
environment