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

Perception of self-motion in Virtual Reality

Perception of self-motion is under natural circumstances a multi-modal experience. Both visual and non-visual information (i.e. proprioceptive, efference copy and vestibular cues) provide rich and partly redundant information about self-motion. This research project investigates how sensory information from different modalities is combined in the vection illusion, which is an illusion of self-motion in stationary observers that can be induced by visual and other sensory stimulation. We also investigated how perceptual and cognitive factors influence the vection illusion.

In a series of experiments, participants were required to judge the onset and strength of vection in either purely visual, or combined visual-auditory, visual-vestibular, or visual-somatosensory conditions. The multi-sensory conditions provided consistent multi-sensory stimulation, for example, a moving sound source that moved coherently with a matching visual target.

Results demonstrated that vection was increased by consistent multi-sensory stimulation such that vection onset latencies were reduced and compellingness ratings were increased. The strongest effect was found for combined visual-vestibular stimulation, where minimalist physical motion cues were provided. We also found that cognitive factors, such as attention and the feeling of presence in the virtual environment, had an influence on perceived vection. These findings have implications for both our theoretical understanding of self-motion perception, as well as motion simulation applications.