0102 Does Targeted Memory Reactivation During Slow Wave Sleep Enhance Emotional Memory in Young Adults

Abstract Introduction Sleep enhances negative emotional memory consolidation in young adults. Targeted memory reactivation (TMR) is thought to increase memory recall for cued items by cuing stimuli with sensory cues during encoding and replaying target cues during sleep. Exposure to TMR during periods of slow wave sleep (SWS) improves declarative and procedural memories. The present study examined whether TMR via olfactory cues during SWS also enhances negative emotional memory consolidation in young adults. Methods Healthy young adults (mean age = 19.78 ± 1.86 years) completed either experiment 1 (Negative and neutral pictures intermixed; N=24) or experiment 2 (Negative and neutral pictures in separate blocks; N=48). Participants learned 36 picture-location pairs, half associated with odor A and the other half associated with odor B and the cued odor was administered during subsequent SWS. Delayed recall occurred after sleep, with no odors or feedback. Polysomnography was recorded and an olfactometer was used to deliver odor cues. Results In experiment 1, TMR enhanced memory for neutral (p=0.03), but not negative stimuli. In experiment 2, TMR had no effect on either negative or neutral stimuli. In experiment 2, poorer initial encoding was associated with a greater cuing benefit, but only for neutral stimuli (p=0.02) and the same relationship was trending towards significance in experiment 1 (p=0.07). In experiment 1, N2 duration was marginally associated with cued neutral memory performance (p=0.06). In experiment 2, cued neutral memory performance was not associated with any sleep stage. Conclusion TMR did not enhance negative memory consolidation in young adults. However, TMR selectively benefitted neutral memories when emotional and neutral stimuli were intermixed. These findings suggest that TMR may preferentially enhance neutral declarative memories when intermixed with negative items and that encoding strength across both experiments modulates its effectiveness. Future analysis will examine sleep microstructures such as spindles, which are a hallmark of N2, to understand potential mechanisms underlying TMR benefits. Support (if any)