Visual properties of neurons in inferotemporal cortex of the Macaque.

IN THE LAST DEC,ADE, considerable progress has been made in understanding the physiology of one of the most fundamental aspects of human experience: perception of the visual world. It is now clear that the retina and visual pathways do not simply transmit a mosaic of Iight and dark to some central sensorium. Rather, even at the retinal level, specific features of visual stimuli are detected and their presence communicated to the next level. In cats and monkeys, the geniculostriate visual system consists of a series of converging and diverging connections such that at each successive tier of processing mechanism, single neurons respond to increasingly more specific visual stimuli falling on an increasingly wider area of the retina (19-Z). How far does this analytical-synthetic process continue whereby individual cells have more and more specific trigger features? Are there regions of the brain beyond striate and prestriatel cortex where this processing of visual information is carrie,d further? If so, how far and in what way? Are there cells that are concerned with the storage of visual information as well as its analysis? There are several lines of evidence suggesting that a possible site for further processing of visual information and perhaps even for storage of such information might, in the monkey, be inferotemporal cortexthe cortex on the inferior convexity of the temporal lobe. First, this area receives afferents from prestriate cortex which itself processes visual information received from