Our understanding of visual processing in the cerebral cortex has undergone major revision since the 1970's. The primary visual cortex of the occipital lobe (also called striate cortex, area 17, or V1), which receives topographically arranged binocular input from the retinas via the lateral geniculate nuclei of the thalamus, was traditionally identified as the region of primary visual perception. Visual association areas adjacent to the straite cortex were assumed to function in higher order processing of the visual percepts formed in the striate cortex (V1), for example, comparison with past visual impressions, or the "interpretation" of images. However, since the 1970's, electrophysiological studies largely in the cat and the macaque monkey have demonstrated numerous anatomically distinct areas outside the striate cortex that are involved in the analysis of specific perceptual attributes such as motion, color, or depth perception. Parallel pathways funnel through V1 to these separate areas, with V1 acting as a segregator of signals to relevant extrastriate areas. In