FEF inactivation increased ipsilesional and contralesional microsaccade amplitudes independently of peripheral cueing.

(A) Unilateral (left) FEF inactivation shifted distributions toward larger amplitudes for each microsaccade direction from example monkey DZ, although we observed larger increases for contralesional microsaccades. Colored bars above the distributions indicate the median, with 25th and 75th percentiles with whiskers extending outward to the 1st and 99th percentiles. (B) Microsaccade amplitudes increased for each monkey (GB, DZ, and OZ) and unilateral (Xr or Xl) or bilateral (Xbi) inactivation configurations, but unilateral FEF inactivation more consistently increased contralesional amplitudes. The shaded area in B indicates microsaccades from our example monkey. (C) Across monkeys, unilateral or bilateral FEF inactivation increased microsaccade amplitudes in both the pre-cue (left) and rebound (right) periods. Filled symbols in B and C indicate statistically significant differences using a Wilcoxon rank sum test (p < 0.05). Data in Supporting Information (see S1 Data).