Does time stop when we blink?
31.26, Sunday, 17-May, 8:15 am - 9:45 am, Talk Room 2
Marianne Duyck1, Thérèse Collins1, Mark Wexler1; 1LPP, Université Paris Descartes, CNRS UMR 8242
Visual perception appears nearly continuous despite frequent disruptions of the input caused by saccades and blinks. While research has focused on perception around saccades, blinks also constitute a drastic perturbation of vision, leading to a complete interruption of the visual input that lasts about 100ms but that we barely notice. Does the visual system actively fill in the missing information or does it simply ignore it? We addressed this question in two experiments in which observers judged the durations of brief visual stimuli in different temporal relations to blinks, using the method of single stimuli. In the first experiment stimuli either straddled the entire blink (onset before the start and offset after the end of the blink), or onset 200ms after the end of the blink. An analysis of the relative biases in the two conditions revealed that stimuli that straddled the blink appeared as 90ms briefer than those that followed the blink—a difference equal to about 77% of the mean blink duration. In a second experiment, the stimulus straddled the end of the blink (onset during the blink, offset after the end), or onset either just after or 200ms following the end of the blink. The optically visible durations of the stimuli that straddled the end of the blink were overestimated by about 20ms in comparison to stimuli that appeared long after. Significantly, we found that in both experiments the duration errors were correlated with trial-by-trial variations in blink durations. Thus, our results suggest that the default mode of the visual system is to ignore the absence of information during blinks. However, in the case of unexpected events, vision partially fills in the blink.