Emotional Amplifier: How Event Boundaries influence Time and Source Memory

Everyday experiences are segmented into discrete events by changes in context, which in turn shapes the organization of our memory. Yet, how event segmentation is modulated by emotional arousal remains poorly understood. Extending prior work, our study examines whether negative emotional arousal alters event segmentation, and how these two factors transform episodic memory processing. We investigated this issue using a sequence learning task, wherein participants studied negative and neutral images presented in stable or changing contexts. The event contexts were established via either auditory modality in Experiment 1 (n = 61) or visual modality in Experiment 2 (n = 60). Consistent with previous work, the results demonstrate that event boundaries segment episodic memory as reflected in both temporal and source memory. Notably, negative emotional arousal amplified these boundary effects in a modality-dependent manner, exerting a greater influence on temporal distance estimations in auditory context and on source memory in visual context. Exploratory correlations revealed that temporal order and temporal distance memory were closely related, and this correlation was reversed by event boundaries and was disrupted under negative emotional arousal. Control analyses further confirmed that these effects remained stable when low-dimensional features were balanced across negative and neutral images. Collectively, our findings illuminate a nuanced interplay between event boundaries and negative emotional arousal, offering a comprehensive perspective on how these two factors jointly shape multiple facets of episodic memory.