BEHAVIORAL ENHANCEMENT OF VISUAL RESPONSES OF PRESTRIATE NEURONS OF THE RHESUS-MONKEY

Abstract

Neurons in the superior colliculus, striate cortex, frontal eye fields and posterior parietal cortex of the monkey respond to visual stimuli. Many of these cells discharge more intensely to a stimulus when it is the target for a saccadic eye movement than when fixation is maintained. This enhancement of the visual response is present for cells in prestriate cortex. The prestriate effect is a modulation of the visual response and not a concomitant of oculomotor activity. It is present for eye movements away from and into the visual receptive field. This effect is similar to that in the striate cortex and different from that in the superior colliculus, frontal eye fields and posterior parietal cortex. The visual responses of many prestriate cells habituate with repeated stimulation. When the monkey makes saccadic eye movements to a stimulus eliciting only a habituated response, the enhancement acts as a dishabituation which persists throughout the eye movement trials.