Understanding the roles of central and autonomic activity during sleep in the improvement of working memory and episodic memory

The last decade has seen significant progress in identifying sleep mechanisms that support cognition. Most of these studies focus on the link between electrophysiological events of the central nervous system during sleep and improvements in different cognitive domains, while the dynamic shifts of the autonomic nervous system across sleep have been largely overlooked. Recent studies, however, have identified significant contributions of autonomic inputs during sleep to cognition. Yet, there remain considerable gaps in understanding how central and autonomic systems work together during sleep to facilitate cognitive improvement. In this article we examine the evidence for the independent and interactive roles of central and autonomic activities during sleep and wake in cognitive processing. We specifically focus on the prefrontal-subcortical structures supporting working memory and mechanisms underlying the formation of hippocampaldependent episodic memory. Our Slow Oscillation Switch Model identifies separate and competing underlying mechanisms supporting the two memory domains at the synaptic, systems, and behavioral levels. We propose that sleep is a competitive arena in which both memory domains vie for limited resources, experimentally demonstrated when boosting one system leads to a functional trade-off in electrophysiological and behavioral outcomes. As these findings inevitably lead to further questions, we suggest areas of future research to better understand how the brain and body interact to support a wide range of cognitive domains during a single sleep episode.

Automated summary

Significant progress has been made in understanding the sleep mechanisms that support cognition, with most research focusing on the electrophysiological events of the central nervous system. However, recent studies have highlighted the importance of the autonomic nervous system during sleep in contributing to cognition. This article examines the independent and interactive roles of the central and autonomic activities during sleep and wakefulness in cognitive processing, specifically in working memory and hippocampal-dependent episodic memory. The Slow Oscillation Switch Model proposes separate and competing mechanisms supporting these two memory domains. Further research is needed to understand how the brain and body interact during sleep to support various cognitive functions.