The three chapters that follow this introduction all deal with aspects of visual perception related to the processing of scenes and the recognition of objects. There was a time when it was clear that higher order visual perception meant processing that took place in brain areas beyond the primary visual cortex. The primary visual cortex was thought to perform simple computations, each covering a small separate part of the visual world (receptive field) and hard wired in the sense that little could be done by learning or attention to modify them. This view stressed hierarchical processing among visual areas, particularly those from primary visual cortex V1 to the anterior temporal areas. Evidence for the hierarchical view is thoroughly summarized in the chapter by Kastner, De Weerd, and Ungerleider. However, all the three chapters deal in rather different ways with qualification to the hierarchical view of visual areas driven passively from the bottom up, based upon the influence of context, attention, and task demands.

In his chapter, Charles Gilbert describes the research work of his group, which has changed the view of how the primary visual cortex works. The older view gave rise to the hope that studies of primary visual cortex might provide the basic immutable building blocks from which it might be possible to launch an analysis of the remaining functions grouped under the title of higher perception.