Schedule of Events | Symposia

How Changes in Mental Replay Speed Impact Retrospective Duration Judgments of Past Events?

Poster Session C - Sunday, March 30, 2025, 5:00 – 7:00 pm EDT, Back Bay Ballroom/Republic Ballroom

Wing Yin Winny Yue¹ (winnyue@connect.hku.hk); ¹The University of Hong Kong

We often replay memory episodes mentally in daily life at varying speeds for different purposes. Previous research has shown that our memory of the event structure, particularly the number of event boundaries, significantly influences how we retrospectively judge the duration of entire memory episodes. Nevertheless, when the structure of the event is maintained, how does manipulating mental replay influences retrospective duration judgement? In the current study, participants watched video clips depicting everyday life events, with subevents separated by clear event boundaries, while EEGs were recorded. Immediately after viewing a video, participants were instructed to mentally replay the event at one of three replay speeds—compressed, expanded, or at their natural pace. We then measured both the natural replay duration and retrospective duration judgments. Analyzing EEGs during video viewing showed that participants detected event boundaries as evidenced by two significant clusters: one within the delta-theta band and another within the sigma-beta-gamma band (two-tailed t-tests with cluster-based permutation correction). During post-encoding mental replay, participants successfully adhered to the manipulated replay speeds, with slower speeds resulting in longer natural replay durations. However, retrospective duration judgments were not influenced by the manipulation of speed of mental replay. Overall, these findings suggest that while individuals can flexibly adjust the speed at which they mentally replay events, retrospective duration judgments are neither updated nor affected by the dynamics of post-encoding replay.

Topic Area: LONG-TERM MEMORY: Episodic