SPATIOTEMPORAL CHARACTERISTICS OF HUMAN MOTION PERCEPTION

A bi-local detector array model was assumed to describe the functional performance of monocular motion perception. Distributions of model pa rameters were measured in human vision at several positions in the vis ual field. The stimulus paradigm was designed to measure directional m otion perception thresholds for individual combinations of spatial dis placement and temporal delay in random dot apparent motion stimuli. Th e resulting data support previous results on perceivable spatial displ acement limits in human vision but also indicate that both minimum and maximum perceivable spatial displacement thresholds in human observer s have a similar dependence on temporal delay. This dependence changes with eccentricity in the visual field in a qualitatively similar mann er but by quantitatively different factors. A description of possible biological properties of the bi-local detector population is presented that may explain how detection of spatio-temporal pattern displacemen ts can be performed by a single system. Such a system also predicts th at minimum and maximum perceivable spatial displacement thresholds sho uld scale with visual field eccentricity in a manner consistent with o ur results.