Hierarchical Processing of Motion in the Visual Cortex of Monkey

Recent work on the visual system of primates has delineated several cortical fields involved in the pro-cessing of visual motion. These cortical areas appear to be connected anatomically in stages, which suggests that there is a hierarchy in the machinery for motion perception. In this paper, we outline experiments hat we have performed along the most prominent pathway for motion analysis, which begins in area V1 and pro-ceeds through the middle temporal area (MT) to the medial superior temporal area (MST). Our goal has been to demonstrate what sequential processing steps take place at each anatomical stage in this presumably hierarchical system. In the first section, we show how a special class of stimuli, transparent motions, have en-abled us to separate distinct and different mechanisms