Abstract
Visual directions of foveal targets flashed just prior to the onset of a saccade are misperceived in head-centric space as shifted in the direction of the eye movement. In previous studies, we demonstrated unequal monocular perisaccadic spatial distortions of two sequentially presented pre-saccadic foveal flashes whose magnitude depended on luminance, temporal interactions and the saccade suppression (VSS 2007,VSS 2008,JOV). These effects were interpreted as a consequence of integrating estimates of eye position with retinal image position over the interval of the temporal impulse response function. We have also demonstrated that two sequentially presented dichoptic pre-saccadic foveal flashes appeared diplopic (in head-centric space) and this zero-retinal image disparity produced stereo-depth eye (SFN 2006). The current study examined whether the perisaccadic stereo-depth percept with dichoptic sequentially flashed pre-saccadic foveal stimuli could be predicted by the direction and magnitude of perisaccadic spatial distortions found with monocular sequentially flashed pre-saccadic foveal stimuli.
Two sequential pre-saccadic flashes (1 ms duration; 50 ms stimulus onset asynchrony) presented monocularly within 20ms prior to saccade onset, produced larger displacements of the first than second flash. The corresponding disparity predicted for two sequentially presented dichoptic pre-saccadic foveal flashes was consistent with the direction of empirically measured peri-saccadic stereo-depth percepts. These results can be interpreted as demonstrating stereo-depth from zero-retinal disparity associated with a non-zero head-centric disparity that results from the combination of retinal image location with independent estimates of each eye's position over the interval of the temporal impulse response.
Supported by NSF-BCS-0715076.