Memory consolidation during sleep involves context reinstatement in humans

• Published in: Cell reports (Cambridge) Vol. 42; no. 4; p. 112331
• Main Authors: Schechtman, Eitan, Heilberg, Julia, Paller, Ken A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 25.04.2023; Elsevier
• Subjects: context; contextual reinstatement; CP: Neuroscience; Cues; Humans; memory consolidation; Memory Consolidation - physiology; Mental Recall - physiology; sleep; Sleep - physiology; Spatial Memory; targeted memory reactivation; sleep; targeted memory reactivation; context; memory consolidation; CP: Neuroscience; contextual reinstatement
• DOI: 10.1016/j.celrep.2023.112331
• ISSN: 2211-1247

New memories are not quarantined from each other when first encoded; rather, they are interlinked with memories that were encoded in temporal proximity or that share semantic features. By selectively biasing memory processing during sleep, here we test whether context influences sleep consolidation. Participants first formed 18 idiosyncratic narratives, each linking four objects together. Before sleep, they also memorized an on-screen position for each object. During sleep, 12 object-specific sounds were unobtrusively presented, thereby cuing the corresponding spatial memories and impacting spatial recall as a function of initial memory strength. As hypothesized, we find that recall for non-cued objects contextually linked with cued objects also changed. Post-cue electrophysiological responses suggest that activity in the sigma band supports context reinstatement and predicts context-related memory benefits. Concurrently, context-specific electrophysiological activity patterns emerge during sleep. We conclude that reactivation of individual memories during sleep evokes reinstatement of their context, thereby impacting consolidation of associated knowledge. [Display omitted] •Memory cues presented during sleep impact non-cued contextually bound memories•Contextual benefits are linked with sigma-band electrophysiological activity•Context-specific electrophysiological activity patterns emerge during sleep•Our results show that memories that were made together subsequently replayed together Memories are embedded in specific encoding contexts, and these contexts are critical for guiding retrieval. In this report, Schechtman et al. show that contexts also play a role during intermittent consolidation during human sleep. Context reinstatement drives changes in performance and is accompanied by electrophysiological activity in the sigma band.