Lighting-from-above prior in biological motion perception.

ABSTRACT: The visual system is able to recognize body motion from impoverished stimuli. This requires combining stimulus information with visual priors. We present a new visual illusion showing that one of these priors is the assumption that bodies are typically illuminated from above. A change of illumination direction from above to below flips the perceived locomotion direction of a biological motion stimulus. Control experiments show that the underlying mechanism is different from shape-from-shading and directly combines information about body motion with a lighting-from-above prior. We further show that the illusion is critically dependent on the intrinsic luminance gradients of the most mobile parts of the moving body. We present a neural model with physiologically plausible mechanisms that acc

SUBMITTER: Fedorov LA 

PROVIDER: S-EPMC5784142 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature