0246 STRESS PRIOR TO ENCODING AFFECTS RESTING STATE FUNCTIONAL CONNECTIVITY AND EMOTIONAL MEMORY RETRIEVAL FOLLOWING SLEEP

Abstract

Previous work has illustrated that sleep and stress enhance long-term emotional memory. Although memory for emotionally arousing items is strengthened following stress exposure, it is unclear how consolidation-related neural processes are affected. The purpose of this project was to examine whether a psychosocial stressor administered before encoding would influence subsequent emotional memory retrieval following a night of sleep through changes in the functional coupling of the ventral medial prefrontal cortex (vmPFC) and the amygdala. Participants underwent either the Trier Social Stress Test or a control task before encoding a series of negative, positive and neutral scenes while we collected functional magnetic resonance imaging (fMRI) data. Overnight sleep was recorded using polysomnography. The following day, participants returned to the MRI to complete an incidental recognition task. Change in functional connectivity was examined by comparing the resting state fMRI scans following the stress manipulation and shortly before the recognition task. Resting state fMRI data collected shortly before the recognition task revealed that greater functional coupling between the amygdala and the vmPFC post-sleep was associated with negative memory enhancement (negative d’ minus neutral d’) in participants who underwent the psychosocial stressor, β = .51, p = .02 (n = 18). Furthermore, negative memory enhancement was associated with a greater increase in coupling between the amygdala and vmPFC from the encoding to retrieval sessions, β = .46, p = .05. The participants in the stress condition who remembered more negative scenes compared to neutral scenes showed greater functional coupling between the amygdala and the vmPFC post-sleep. These preliminary results suggest that stress prior to encoding affects consolidation-related brain networks important for emotional memory function. National Science Foundation Grant Reward Number: BCS1539361.