Fig. 9.
Microsaccades acted to primarily correct for foveal motor errors during gaze fixation. We plotted gaze distance from the fixation spot before and after microsaccades, for all microsaccades that were used in the analyses of Figs. 3, 5, and 7. During both experiments, microsaccades brought gaze closer to the fixation spot than before the movements (P = 1.2111 × 10−54 in experiment 1 and P = 6.9096 × 10−29 in experiment 2; Wilcoxon rank sum test), consistent with recent observations in previous studies. This suggests that our microsaccades were not necessarily reflecting endogenous attention shifts towards the periphery but were instead part of a deliberate oculomotor strategy to optimize eye position on the fixated target.