Perisaccadic visual perception

Primates use frequent, rapid eye movements to sample their visual environment. This is a fruitful strategy to make the best use of the highly sensitive foveal part of the retina, but it requires neural mechanisms to bind the rapidly changing visual input into a single, stable percept. Studies investigating these neural mechanisms have typically assumed that perisaccadic perception in nonhuman primates matches that of humans. We tested this assumption by performing identical experiments in human and nonhuman primates. Our data confirm that perisaccadic visual perception of macaques and humans is qualitatively similar. Specifically, we found a reduction in detectability and mislocalization of targets presented at the time of saccades. We also found substantial differences between human and nonhuman primates. Notably, in nonhuman primates, localization that requires knowledge of eye position was less precise, nonhuman primates detected fewer perisaccadic stimuli, and perisaccadic compression was not towards the saccade target. The qualitative similarities between species support the view that the nonhuman primate is ideally suited to study aspects of brain function—such as those relying on foveal vision—that are uniquely developed in primates. The quantitative differences, however, demonstrate the need for a reassessment of the models purportedly linking neural response changes at the time of saccades with the behavioral phenomena of perisaccadic reduction of detectability and mislocalization.