Antisaccade velocity, but not latency, results from a lack of saccade visual guidance.

Antisaccades are slower in peak velocity, more dysmetric, and longer in latency than prosaccades. This study used a novel visually guided antisaccade task to determine how visual target presence affects antisaccade metrics. The results showed that peak velocity and endpoint error of visually guided antisaccades were more similar to prosaccades than to traditional antisaccades, whereas their latencies were similar to those of traditional antisaccades. The velocity of prosaccades, and to a lesser extent that of antisaccades, were boosted by the sudden appearance of a target. These results suggest that the lower velocity and increased dysmetria of traditional antisaccades result from the absence of a visual target, but their longer latency is more likely a result of suppressing a prosaccadic reflex.