Schedule of Events | Symposia

Sex differences in episodic memory reinstatement: An fMRI study

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

Hallie Liu¹, Sricharana Rajagopal¹, Gabriela Vélez Largo¹, Natasha M. Rajah^1,2; ¹Toronto Metropolitan University, ²McGill University

Introduction: Episodic recollection of contextual details has been associated with successful reinstatement (or reactivation) of neural activity patterns observed at encoding, at the time of retrieval. However, past work has not examined if the same patterns of reinstatement support context retrieval in males and females despite the large body of evidence for sex differences in episodic memory. Methods: The current fMRI study sought to fill this knowledge gap by testing for sex differences in reinstatement. Twenty-four females (age 22-38) and 24 males (age 21-36) completed a spatial context memory task during an fMRI scan. During the encoding phase of the task, faces were presented individually in one of four quadrants. In the retrieval phase, participants had to recall which quadrant each face was previously presented in. To ensure sex differences were not driven by behavioral differences, female and male subjects were matched on memory accuracy scores. Using conjunction analysis, we examined reinstatement by analyzing the encoding-retrieval activity overlap in subjects, and compared brain regions that showed activity overlap between females and males. Results: Both sexes showed similar encoding-retrieval activity overlap, specifically in the occipital cortex and paracingulate gyrus. However, female subjects showed more extensive overlap in the middle frontal gyrus and fusiform gyrus, while male subjects showed more extensive overlap in the parietal cortex. Conclusions: Overall there were sex similarities in the observed reinstatement patterns. However, some sex differences were also observed, suggesting that certain regions may contribute to episodic recollection to different degrees in females and males.

Topic Area: LONG-TERM MEMORY: Episodic