Visual-tactile saccadic inhibition.

In an eye movement countermanding paradigm it is demonstrated for the first time that a tactile stimulus can be an effective stop signal when human participants are to inhibit saccades to a visual target. Estimated stop signal processing times were 90-140 ms, comparable to results with auditory stop signals, but shorter than those commonly found for manual responses. Two of the three participants significantly slowed their reactions in expectation of the stop signal as revealed by a control experiment without stop signals. All participants produced slower responses in the shortest stop signal delay condition than predicted by the race model (Logan and Cowan 1984) along with hypometric saccades on stop failure trials, suggesting that the race model may need to be elaborated to include some component of interaction of stop and go signal processing.