FIG. 4.

Effect of blink time on saccade latency. A: saccade latency is plotted as a function of blink time across all SSDs for all noncancelled trials, i.e., a saccade was generated. For monkey TY, the air-puff timing in the countermanding task was constrained to not evoke blinks >200 ms before target onset. The relationship between blink time and saccade latency is similar for target step (blue squares) and noncancelled countermanding trials (magenta circles). The effect of blink on saccade latency can be parsed into four clusters (Gandhi and Bonadonna 2005). Cluster 1, blinks occur long before target onset and have no effect on saccade latency; cluster 2, blinks occur around target onset and increase saccade latency, most likely because the eyes are closed or closing when the visual target is presented; cluster 3 (points covered in the dotted ellipse), blinks evoked after the saccade target is processed reduces saccade latency by triggering the eye movement during the blink itself; cluster 4, the blink is evoked after the saccade reaction time. This cluster categorization is referenced by the text describing Monte Carlo simulations of the race model. B: histograms of blink time for cancelled trials, i.e., no saccade generated. Binwidth = 25 ms.