Dependence of averaged eye velocities on experimental conditions: A. Left eye; B. Right eye. Averages among all subjects are shown for the saccade toward the left (red lines) and right (blue lines) in the sessions of Go-Only (left panels) and Go/NoGo (right panels), on the 1st day (solid lines) and 2nd day (dashed lines). Positive deflections of velocity of eye movements toward saccadic target. Horizontal axes are the latency from the saccade initiation. The latencies of significantly faster movements are denoted by red square brackets for the leftward saccade relative to the rightward, and by cyan square brackets for the saccades on the 2nd day than 1st day. The significant differences were revealed by ANOVA factoring the saccade direction, the session type, the experiment day and the subject (p < 0.05 for 10 ms or more). C. Time courses comparisons between the eyes based on the significant differences. The latencies of significant difference with respect to the saccade directions are indicated by red horizontal bars. The onsets of the significant difference are linked between the eyes by a thin red line, showing eye yoking. Cyan horizontal bars linked by a thin line indicated the yoking found based on the significant day effect.