chapter  2
50 Pages

Disorders of perception

A strong hypothesis is that the computations that are taking place in the primary visual cortex (striate cortex), which map out our "here and now" visual experience, are at the same time being supplemented by "top-down" information concerning what we already know and what we expect to see. These already stored features are likely to guide our "bottom-up" analysis, which is dedicated to the analysis of the external environment in terms of contour, colour, texture, luminance, and motion. In this manner we do not start afresh each time we perceive; rather we use past stored perceptual experience to metaphorically guide the perceptual analysis of visual information.