Abstract
Microsaccades are miniature replicas of the saccadic gaze shifts normally used to look at different objects in the scene. Unlike their larger counterparts, microsaccades maintain the stimulus within the foveola, the retinal region with highest visual acuity, raising the question of why observers make them. One of the long-standing proposals on the visual functions of microsaccades is that they enable exploration of small regions in the scene in the same way saccades are normally used to scan larger regions. Recent results based on improved methods for localizing the center of gaze have provided strong support to this proposal. They have shown that when humans are not requested to maintain prolonged fixation on a point--a common, yet unnatural, condition in vision research experiments--they use microsaccades to precisely center gaze on nearby details of interest. These small gaze shifts are critical in high-acuity tasks and occur because of an eccentricity-dependent decline in visual functions even within the foveola itself. Here we will review this body of results and quantify the different costs of making and not making microsaccades.
Meeting abstract presented at the 2016 OSA Fall Vision Meeting