A saccade is a high-speed eye movement that shifts gaze from one fixation point to another, reaching maximum velocities of 500-700°/s. Visual information acquisition is suppressed during the movement (saccadic suppression). Saccade latency (time from stimulus onset to eye movement initiation) is typically 150-250ms, and this latency forms the foundation of visual reaction speed. Generated through coordination of the frontal eye fields and superior colliculus, both latency and accuracy are improvable through training.
Neural Control of Saccades
Saccades are generated through coordination of regions including the Frontal Eye Fields (FEF), Supplementary Eye Fields (SEF), and superior colliculus. FEF handles voluntary saccade planning, while the superior colliculus transmits execution commands to brainstem oculomotor nuclei. In single-cell recordings from a motor area of the cerebral cortex in monkeys, movements were initiated only when neural activity reached a constant threshold, and variability in the rate at which activity grew toward that threshold produced the distribution of reaction times.
Saccades and Cognitive Performance
Saccade efficiency is involved in visual search task performance. One account holds that experts concentrate fixations on information-rich regions with fewer wasteful saccades. Saccades with especially short latencies are called express saccades.
Training Saccade Ability
A study comparing video game players and non-players on tasks including anti-saccades (looking opposite to the stimulus) reported shorter saccade latencies in players and no significant difference in anti-saccade error rates.