Abstract
Visual direction of foveal targets flashed just prior to the onset of a saccade is misperceived as shifted in the direction of the eye movement. We examined the effects of luminance level and temporal interactions on the amplitude of these perisaccadic spatial distortions (PSDs). PSDs for single-flashed stimuli were larger with low than high luminance levels, and there was a reduction of PSDs for low luminance targets flashed immediately before the saccade. PSDs for two sequential pre-saccadic flashes (ISI = 50 ms) differed from predictions based on a single-flash: PSD was increased for the first flash and reduced for the second. Paradoxically, when the two pre-saccadic flashes were presented near the saccade onset, the earlier flash was distorted more than the later flash, even though the later flash occurred closer in time to the saccade.
This research was supported by National Science Foundation NSF-. BCS-0715076.