Modeling the processing and perception of visual motion

The processing of motion information is a fundamental and elementary function in biological visual systems. Perception of depth, segregation of objects, discrimination of figure from the ground, and detection of moving objects are a few tasks among many others that rely on visual motion perception; see (Nakayama 1985) for a review. Sophisticated mechanisms for extracting and utilizing motion information exist even in simple animals. For example, the ordinary housefly can separate a moving object from its surround on the basis of motion information alone (Egelhaaf 1985; Reichardt 1986; Reichardt and Poggio 1979). The frog does not recognize a dead insect as food; however, the frog has efficient “bug-detection” mechanisms that respond selectively to small, dark objects moving across its visual field (Lettvin et al. 1959).