Temporal compression of emotional events in episodic memory: Reduced compression for negative but not positive events

Naturalistic events are temporally compressed in episodic memory, such that remembering an event generally takes less time than the duration of the original episode. A recent study using video stimuli showed that this temporal compression was reduced for negative events: mental replay duration, relative to actual video length, was longer for negative than neutral videos. In the present study, we tested whether this effect extends to positive events. Participants viewed a series of negative, positive, and neutral videos, then mentally replayed them and described their memories. Results showed that negative events were less temporally compressed than both neutral and positive events, whereas positive and neutral events did not differ. Consistently, verbal descriptions of memories contained more information and episodic details for negative than neutral and positive videos. However, both negative and positive memories were perceived as more detailed, more dynamic, and less difficult to recall than neutral ones. Overall, while negative emotion enhanced both objective and subjective memory measures, positive emotion influenced only subjective experience, revealing a dissociation between objective and subjective aspects of memory for positive events.