The role of emotional content in segmenting naturalistic videos into events.

(moments that separate two events) of different grains (Experiment 1: neutral grain; Experiment 2: fine grain or coarse grain). We found that participants agreed with each other about when emotion changes occurred in the videos, demonstrating that viewers are able to track changes in the emotional content of dynamic naturalistic videos as they are experienced. Moreover, the emotion changes participants identified were temporally aligned with the event boundaries identified by other groups. In addition, valence and arousal changes rated by a separate group of participants uniquely predicted the likelihood of identifying emotion changes and event boundaries, even after accounting for other types of change. However, emotion changes were more strongly tied to valence changes than arousal changes while coarse boundaries were more strongly associated with affective changes than were fine boundaries. These novel findings suggest that emotional information plays a substantial role in structuring ongoing experiences into meaningful events, providing a stronger basis for understanding how emotion shapes the perception and memory of everyday experiences. (PsycInfo Database Record (c) 2025 APA, all rights reserved).