0098 The Effects of Targeted Memory Reactivation During a Daytime Nap on Sensorimotor Skill Performance in Healthy Young Adults

Abstract

Introduction: Neural replay occurs during sleep to strengthen individual memories. Non-invasive methods of sensory stimulation during sleep have been developed to enhance this process. A widely used method known as targeted memory reactivation (TMR) involves classical conditioning of an auditory cue paired with task performance during initial skill acquisition, followed by cue replay during sleep. Our previous work demonstrated that TMR throughout the first two slow wave cycles of overnight sleep, but not daytime wakefulness, enhanced non-dominant arm throwing accuracy. The purpose of the current study was to determine whether TMR throughout a one hour afternoon nap is sufficient to enhance non-dominant arm throwing accuracy. Methods: The protocol involved repetitive non-dominant arm throwing to unique visuospatial targets, and auditory cues distinctively paired with each target. For participants receiving TMR, these same auditory cues were repetitively replayed either during napping or wakefulness. The primary and secondary outcomes of absolute and variable throwing error distance, respectively, were collected at four time points (baseline, post initial training session, post one-hour nap, and post second training session). Healthy adults were divided into groups based on the inter-training interval: Wakefulness+NoTMR (n=12), Wakefulness+TMR (n=12), Napping+NoTMR (n=12), Napping+TMR (n=10). Results: A between-group difference was found in absolute error change score ratios between the end of the first session and beginning of the second session (p=0.038), with Napping+TMR demonstrating greater error reduction than Wakefulness+NoTMR (p=0.025). Between sessions, variable error increased similarly in both waking groups, but decreased similarly in both napping groups (napping vs. wakefulness: p=0.011). Conclusion: These findings suggest that TMR throughout a nap is sufficient to enhance sensorimotor performance, and that a nap is sufficient to decrease performance variability. Data collection continues, and future analyses will investigate the effects of sleep quality and quantity with and without TMR.