Understanding mental replay duration for continuous events: the roles of recall initiation and central tendency

Remembering past events usually takes less time than their actual duration - events are temporally compressed in memory. A recent study found that this compression is not systematic but emerges when continuous events exceed approximately 9 s. Unexpectedly, however, remembering shorter events (3-6 s) took more time than their actual duration. Here, we aimed to investigate the mechanisms behind this increased replay duration of short events. In Experiment 1, we developed a corrected measure accounting for recall initiation time - the time needed to access the beginning of the event. With this correction, the longer replay times for short events disappeared, suggesting the effect was partly due to unmeasured recall initiation time. In Experiment 2, we examined the potential role of a central tendency bias by exposing participants to different ranges of event durations. Replay duration was influenced by the event's relative position within the duration range, consistent with a central tendency bias. However, for events longer than 9 s, temporal compression occurred consistently across all conditions. Together, these findings suggest that while central tendency influences replay duration, temporal compression systematically emerges when events exceed a few seconds, likely reflecting memory capacity limits in representing continuous experiences.