Remembered event features shape default mode network engagement during emotional memory recall.

Abstract

Episodic memory involves reconstruction of past events through integration of multiple types of information, including perceptual details, narrative content, and emotional tone. The default mode network (DMN) is a set of regions thought to support episodic retrieval, yet it remains unclear how distinct subnetworks contribute to recall of these different memory features. Here, we examined how DMN subnetworks support and represent memory for naturalistic emotional events. Male and female human participants encoded short news videos that varied in emotional valence and recalled them in response to neutral cues during functional MRI scanning. Videos were again recalled one day later and memories were scored for perceptual and narrative details. Activity in the dorsomedial subnetwork was related to the emotional valence of the memory, while activity in the medial temporal subnetwork was associated with the number of perceptual details recalled. Multivariate pattern analyses further revealed that the medial temporal subnetwork exhibited greater pattern stability across recalls when recalling more perceptual details, while stability in the dorsomedial and core subnetworks was tied to emotional remembering. Our findings suggest that the dorsomedial subnetwork provides an affective frame for a memory, while the medial temporal subnetwork contributes perceptual specificity. These results demonstrate that the contents of memory retrieval shape network engagement during emotional recall, providing insight into how the brain reconstructs complex real-world experiences.Significance Statement How do we remember the emotional tone of an event versus its visual details? This study examines how distinct subnetworks within the brain's default mode network (DMN) contribute to remembering different features of memory. While the medial temporal subnetwork is connected to retrieving the perceptual details of past events, the dorsomedial subnetwork supports recall of the emotional tone. Furthermore, patterns of activity in the medial temporal subnetwork are more stable when recalling more perceptually rich memories, while stability in the dorsomedial subnetwork is tied to emotional remembering. These findings suggest that the default mode network flexibly responds to different kinds of memory features, supporting the reconstruction of rich emotional memories from complex real-world experiences.