Sleep loss disrupts the neural signature of successful learning

Abstract

Sleep supports memory consolidation as well as next-day learning. The influential Active Systems account of offline consolidation suggests that sleep-associated memory processing paves the way for new learning, but empirical evidence in support of this idea is scarce. Using a within-subjects (N = 30), crossover design, we assessed behavioural and electrophysiological indices of episodic encoding after a night of sleep or total sleep deprivation in healthy adults (aged 18-25 years), and investigated whether behavioural performance was predicted by the overnight consolidation of episodic associations formed the previous day. Sleep supported memory consolidation and next-day learning, as compared to sleep deprivation. However, the magnitude of this sleep-associated consolidation benefit did not significantly predict the ability to form novel memories after sleep. Interestingly, sleep deprivation prompted a qualitative change in the neural signature of encoding: whereas 12-20 Hz beta desynchronizationan established marker of successful encodingwas observed after sleep, sleep deprivation disrupted beta desynchrony during successful learning. Taken together, these findings suggest that effective learning depends on sleep, but not necessarily sleepassociated consolidation.

Delineating memory reactivation in sleep with verbal and non-verbal retrieval cues

“…Screening questionnaires indicated that participants had no history of sleep, neurological or psychiatric disorders, were non-smokers and were not using any psychoactive medications. Following standard practices in our lab, participants were instructed to refrain from alcohol and caffeine for 24 hours before the start of the study (Ashton et al, 2019;Cairney, Lindsay, et al, 2018;Guttesen et al, 2022;Strachan et al, 2020). The Pittsburgh Sleep Quality Index (Buysse et al, 1989) indicated that all participants had a normal pattern of sleep in the month preceding the study.…”

Temporary amnesia from sleep loss: A framework for understanding consequences of sleep deprivation

“…Based on the accumulating evidence that the functioning of the hippocampus and associated MTL areas are disrupted by sleep deprivation in humans and in animal models (Tudor et al, 2016;Guttensen et al, 2023), it would be surprising if we did not observe significant effects of sleep loss on memory. However, to understand what aspects of memory are, and are not, affected by sleep deprivation requires a deeper understanding of the role of the hippocampus in memory.…”