Saccade-induced temporal distortion: opposing effects of time expansion and compression

Saccadic eye movements, or saccades, can distort our perception of time, as evidenced by the phenomenon of Chronostasis, where the first event after a saccade appears to last longer than it actually does. However, the impact of saccades on events following the first has never been explored. Here, we compared how participants perceived durations of first and second intervals after a saccade with their perceived durations during fixation, where no saccades occurred. We found that saccades lengthened the perceived duration of the first event, confirming Chronostasis. Moreover, when the second event occurred right after the first, its duration was perceived as shorter. Interestingly, when the second event was used as a reference, the Chronostasis effect was even stronger. Notably, this shortening of the second event persisted even when we ruled out processes like the "attentional blink" that might interfere with the timing between the two events. Our findings suggest that saccades induce a brief, uneven distribution of attentional processing in time, leading to an overestimation of the first and an underestimation of the second interval when the two intervals occur close together.