Neural Model for the Influence of Shading on the Multistability of the Perception of Body Motion

Body motion perception from impoverished stimuli shows interesting dynamic properties, such as multistability and spontaneous perceptual switching. Psychophysical experiments show that such multistability disappears when the stimulus includes also shading cues along the body surface. Classical neural models for body motion perception have not addressed perceptual multistability. We present an extension of a classical neurodynamic model for biological and body motion perception that accounts for perceptual switching, and its dependence on shading cues on the body surface. We demonstrate that a set of psychophysical observations can be accounted for in a unifying manner by a hierarchical neural model for body motion processing that includes an additional shading pathway, which processes luminance gradients within the individual body segments. The goal of our model is to explain psychophysics and neural mechanism in the brain.