Finding Your Way and Dancers in the Dark
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“Finding Your Way: The Differential Role of Sleep Stages in Virtual Maze Spatial Navigation”
Spatial navigation is a complex behavior requiring the integration of memory, perception, attention, motor movement, and decision making, and relies on the hippocampus. Since NREM sleep has been shown to support hippocampal-dependent memory, NREM may also benefit navigation. Yet prior findings are mixed, likely due to heavy reliance on stationary, two-dimensional desktop tasks and the limited use of EEG measures to capture the impact of sleep physiology, such as sleep spindles (12-15Hz), on navigation. To address these gaps, Morehouse investigated sleep’s contribution to spatial navigation using a nap-versus-wake paradigm and an immersive, ambulatory virtual reality (VR) task that more closely approximates real-world navigation. She found that sleep benefits spatial navigation, with a nap immediately after learning improving navigation efficiency at a 48–72-hour follow-up compared to wakefulness. Navigation efficiency reflects consolidation of a cognitive map, i.e., a mental representation of the environment, and was enhanced specifically through sleep spindles, suggesting that spindles support the ability to generate shortcuts and flexibly navigate to remembered locations. Together, this work suggests that sleep plays an essential role in everyday navigation, supporting our ability to move efficiently through the world by refining internal maps of our environment and enabling the flexible use of past experiences to guide future actions.
“Dancers in the Dark: Do Sleep Twitches Predict Sleep-Dependent Consolidation of Whole-Body Motor Learning?”
Whole-body motor learning requires the integration of timing, coordination, sequencing, and sensorimotor prediction across distributed neural systems, including cerebellar, cortical, and brainstem networks. Although sleep has been shown to support the consolidation of fine motor skills, its role in the consolidation of complex, whole-body movement remains unexplored. One candidate mechanism is REM sleep twitching, which are brief, discrete motor events traditionally interpreted as byproducts of dreaming but have been proposed to function as calibration signals for maintaining and refining sensorimotor maps. Recent comparative and developmental work suggests that twitching may help update internal models of movement, yet whether these processes contribute to the acquisition and stabilization of newly learned whole-body skills in adults remains unknown. To address this gap, Uzoigwe investigated whether sleep twitching predicts consolidation of a dance sequence using a multi-day training paradigm combined with polysomnographic nap recordings. Participants learned a structured choreography dance across three days, followed by a monitored nap opportunity during which twitch activity was quantified. Uzoigwe examined whether twitch expression during sleep predicted performance improvements and whether these relationships varied as learning progressed. Preliminary findings confirm performance improvement across training days and increased REM sleep twitching following motor learning, with particularly pronounced changes observed in the feet compared to baseline recordings. With this work, Uzoigwe aims to show initial evidence that REM sleep twitching may play a role in sleep-dependent consolidation of complex motor learning, extending theories of twitch-related plasticity beyond early development to adult motor skill acquisition.
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