How forward remapping predicts peri-saccadic biphasic mislocalization.

Abstract

Neurons in many visual and oculomotor "priority-map" brain areas display forward receptive field (RF) remapping: they respond to stimuli appearing before a saccade at the spatial location that their RF will occupy after the saccade. Concurrently, psychophysical studies have shown that flashes around saccade onset are systematically mislocalized in various patterns. One prominent pattern is a biphasic pattern, where flashes right before a saccade are mislocalized in the saccade direction (forward) and flashes right after a saccade are mislocalized opposite to the saccade direction (backward). Although forward RF remapping and biphasic mislocalization have been suspected to be linked, how this works has never been explained. Here, we show how persistent flash-evoked activity and decoding of the flash position after the saccade combine to produce this biphasic mislocalization pattern. We implement a rate model, consistent with the essential properties of RF remapping, and show that biphasic mislocalization results from insufficient remapping before the saccade, and residual/inappropriate remapping after the saccade. Less remapping before the saccade produces larger forward mislocalization of pre-saccadic flashes, and less remapping after the saccade produces smaller backward mislocalization of post-saccadic flashes. Forward RF remapping thus captures a biphasic peri-saccadic flash-mislocalization pattern consistent with behavioral data.