Running Head: Neural Model of Second-Order Motion Requests for reprints should be sent to:

Abstract

their valuable assistance in the preparation of the manuscript. A neural model of motion perception simulates psychophysical data concerning rst-order and second-order motion stimuli, including the reversal of perceived motion direction with distance from the stimulus (, display), and data about directional judgments as a function of relative spatial phase or spatial and temporal frequency. Many other second-order motion percepts that have been ascribed to a second non-Fourier processing stream can also be explained in the model by interactions between ON and OFF cells within a single, neurobiologically interpreted magnocellular processing stream. Yet other percepts may be traced to interactions between form and motion processing streams, rather than to processing within multiple motion processing streams. The model hereby explains why monkeys with lesions of of the parvocellular layers, but not the magnocellular layers, of the lateral geniculate nucleus (LGN) are capable of detecting the correct direction o