Schedule of Events | Symposia

Event boundary-elicited neural activities correlate with recent and remote memory

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

Zexuan Mu¹ (evokee@connect.hku.hk), Jing Liu², Xiaoqing Hu¹; ¹The University of Hong Kong, ²The Hong Kong Polytechnic University

Although experience unfolds continuously, memories are structured into discrete events through the detection of event boundaries. However, the neural mechanisms of how individuals encode different types of event boundaries during naturalistic episodes, and how boundary-elicited neural activities contribute to long-term memory remain poorly understood. Here, we presented forty-five participants (Mage = 22.31, SD = 2.73) with 60 movie clips, each 23 seconds long, while electroencephalogram (EEG) were recorded. The clips comprised three conditions: no-boundary, soft-boundary (perceptual shift), and hard-boundary (perceptual + conceptual shift), with 20 clips in each condition. Recent and remote memory was assessed immediately, and 7 days after encoding using cued verbal recall tasks. To assess memory, independent raters listened to participants’ verbal recall for each clip and rated the richness of accurately recalled content. We found that, compared to the no-boundary condition, soft and hard boundaries elicited significant EEG power increases in theta (4-7 Hz), beta (13-25 Hz), and low-gamma (26-30 Hz) frequency bands. Further linear mixed-effects model analyses revealed that soft-boundary-elicited beta power was negatively correlated with the rating differences (post-boundary minus pre-boundary) for remote, but not for recent, memories. In addition, hard-boundary-elicited theta power was positively correlated with ratings of remote, but not for recent, memories. The findings suggest that during naturalistic events encoding, boundary-elicited EEG power distinctly predicts remote memories. This study provides novel insights into how people encode different event boundaries in naturalistic experiences and how such encoding impacts subsequent memories of naturalistic events.

Topic Area: LONG-TERM MEMORY: Episodic