Transient stimulation does not aid visual search: Implications for the role of saccades

Previous demonstrations that performance on visual search tasks with briefly flashed presentations declines over time after the initial onset imply that saccades might be necessary for efficient acquisition of visual information. We imposed an additional abrupt onset and a displacement on character arrays containing letters and one numeral while subjects searched for the numeral. Presentations were always followed by a visual noise field. Presentation time varied (50-800 msec). We found that performance with presentations containing one onset and remaining continuously visible was better than performance with presentations containing two onsets and containing displacements. Furthermore, information acquired near the onset of a continuous presentation was as effective as information acquired later. Our results demonstrate that abrupt onsets and displacements do not improve information acquisition with displays of alphanumeric characters. This finding is consistent with earlier reports that saccade-like retinal image motion does not contribute either to the maintenance of target visibility or to visual acuity.