Stimulus Specific Responses from Beyond the Classical Receptive Field: Neurophysiological Mechanisms for Local-Global Comparisons in Visual Neurons

We perceive the visual world as a unitary whole, yet one of the guiding principles of nearly a half century of neurophysiological research since the early recordings by Hartline (1938) has been that the visual system consists of neurons that are driven by stimulation within small discrete portions of the total visual field. These classical receptive fields (CRFs) have been mapped with the excitatory responses evoked by a flashed or moving stimulus, usually a spot or bar of light. Most of the visual neurons, in turn, are organized in a series of maps of the visual field, at least 10 of which exist in the visual cortex in primates as well as additional topographic representations in the lateral geniculate body, pulvinar and optic tectum (Allman 1977, Newsome in the second, examine the anatomical pathways that sub serve these far-reaching surround mechanisms; and in the third, explore the possible relationships between these mechanisms and perception.