Poster F72, Tuesday, March 27, 8:00-10:00 am, Exhibit Hall C
Hippocampal sensitivity to event boundaries in encoding of naturalistic events
Aya Ben-Yakov1, Rik Henson1; 1University of Cambridge
How is continuous real-life experience transformed into memory for discrete events? Event Segmentation Theory suggests that moments of prediction error are interpreted as event boundaries and drive encoding. Using functional magnetic resonance imaging (fMRI), we set out to reveal whether occurrence of event boundaries drives encoding, with a specific focus on the hippocampus. First, using short film clips as memoranda, we found that hippocampal activity time-locked to the offset of events is linked to subsequent memory, potentially reflecting the encoding of a bound representation to long-term memory. Notably, when distinct clips were presented in immediate succession, the hippocampus responded at the offset of each event, suggesting hippocampal activity is triggered the occurrence of event boundaries (transition between events). However, while brief film clips mimic several aspects of real-life, they are still discrete events. To determine whether event boundaries drive hippocampal activity in an ongoing experience, we analysed brain activity of over 200 participants who viewed continuous, naturalistic films in two independent experiments, finding that the hippocampus responded both reliably and specifically to shifts between scenes. Taken together, these results suggest that during encoding of a continuous experience, event boundaries drive hippocampal processing, potentially supporting the transformation of the continuous stream of information into distinct episodic representations.
Topic Area: LONG-TERM MEMORY: Episodic