Individual differences in emotional learning–driven prioritization of neutral episodic memories across temporal boundaries

Episodic memory is shaped by event segmentation, which divides continuous experience into discrete episodes often marked by temporal gaps. Emotional learning can influence memory across these boundaries by prioritizing not only threatening events but also related information that is encoded shortly before or after the emotional episode, which in turn supports adaptive generalization. However, evidence for such cross-boundary modulation is mixed, possibly because conventional group-level analyses can mask systematic individual variability in the effects of emotional learning on nearby neutral memories. We reanalyzed data from a large-sample study (N = 285) combining emotional and episodic learning that had previously shown no consistent retroactive or proactive enhancement across event boundaries at the group level. Young adults incidentally encoded neutral images from two categories (animals, tools) across three temporally separated phases: pre-conditioning, conditioning, and post-conditioning. One category was partially reinforced with mild electric shocks during conditioning to create a category-level threat association. Memory was tested 24 hours later using a surprise old–new recognition task.A hierarchical Bayesian recognition model with a latent-mixture component revealed two profiles of memory modulation. One showed declining memory across phases, with modest enhancement limited to items from the shock-predictive category encoded during conditioning. The other showed strongest memory for items encoded during conditioning, with substantial category-selective enhancement extending into post-conditioning. These findings suggest that proactive, but not retroactive, enhancement is most evident in individuals whose memories are strongly anchored to the emotional episode, indicating integration of threat-related information across temporal boundaries.