Poster Session B, Sunday, March 24, 8:00 – 10:00 am, Pacific Concourse
Effects of cortisol reactivity and REM theta activity on emotional memory consolidation
Sara Y. Kim1, Elizabeth A. Kensinger2, Jessica D. Payne1; 1University of Notre Dame, 2Boston College
Sleep and stress independently have been shown to benefit emotional memory consolidation. In particular, theta oscillations (4-7 Hz) during rapid eye movement (REM) sleep have been linked to coherence in an emotional memory network and enhanced emotional memory. Here, we tested the hypothesis that pre-encoding stress exposure and theta power during REM sleep would interact to predict memory for emotional information. Participants underwent a psychosocial stressor (the Trier Social Stress Task; n = 32) or a comparable control task (n = 32) prior to encoding. Task-evoked cortisol reactivity was assessed by salivary cortisol rise from pre- to post-stressor. Participants in the stress condition were categorized as high or low cortisol responders via median split. During encoding, participants studied 150 negative, neutral, and positive images. All participants slept overnight in the lab with polysomnographic recording. The next day, they were given a surprise recognition memory task. As predicted, high responders exhibited greater cortisol reactivity relative to both low responders (t(15.80) = 6.14, p < 0.001) and controls (t(17.36) = 5.67, p < 0.001). For high responders, REM theta significantly predicted memory for emotional information, specifically for positive items (b = 0.15, R2 = 0.34, p < 0.05). Notably, for low responders and controls, there was no relationship between theta and memory of any valence. These findings provide initial evidence that events occurring at encoding, and accompanying changes in neuromodulators such as cortisol, and theta activity during REM sleep may interact to promote selective consolidation of emotional information during sleep.
Topic Area: LONG-TERM MEMORY: Episodic