Form representation in monkey inferotemporal cortex is virtually unaltered by free viewing.

How are objects represented in the brain during natural behavior? Visual object recognition in primates is thought to depend on the inferotemporal cortex (IT). In most neurophysiological studies of IT, monkeys hold their direction of gaze fixed while isolated visual stimuli are presented (controlled viewing). However, during natural behavior, primates visually explore cluttered environments by changing gaze direction several times each second (free viewing). We examined the effect of free viewing on IT neuronal responses in monkeys engaged in a form-recognition task. By making small, real-time stimulus adjustments, we produced nearly identically retinal stimulation during controlled and free viewing. Nearly 90% of neuronal responses were unaffected by free viewing, and average stimulus selectivity was unchanged. Thus, neuronal representations that likely underlie form recognition are virtually unaltered by free viewing.