Journal of Cognitive Neuroscience 11:2

■ Relative to when a fixated stimulus remains visible, saccadic latencies are facilitated when a axated stimulus is extinguished simultaneously with or prior to the appearance of an eccentric auditory, visual, or combined visual-auditory target. In a study of nine human subjects, we determined whether such facilitation (the “gap effect”) occurs equivalently for the disappearance of axated auditory stimuli and axated visual stimuli. In the present study, a axated auditory (noise) stimulus remained present (overlap) or else was extinguished simultaneously with (step) or 200 msec prior to (gap) the appearance of a visual, auditory (tone), or combined visual-auditory target 10° to the left or right of axation. The results demonstrated equivalent facilitatory effects due to the disappearance of axated auditory and visual stimuli and are consistent with the presumed role of the superior colliculus in the gap effect. ■