Adaptation of saccades and fixation to bilateral foveal lesions in adult monkey

Abstract

Bilateral foveal lesions were made by laser photocoagulation in adult monkeys. One day post-lesion, animals fixated with a new retinal locus inferior to the fovea (in the visual field) that they used permanently. Fixation stability improved modestly over two days. Initially, saccades maladaptively brought the lesioned foveae to visual targets. Over at least several weeks, saccade trajectories gradually changed bringing targets to intact retina, although some animals never totally adapted. The slow time course of saccadic adaptation to foveal loss suggests a mechanism different from that documented in other studies of saccadic adaptation and from that used by the fixation system.