Detecting Biased Memory Reactivation During Sleep with a Laterally Asymmetric Signal

Abstract

During slow-wave sleep, memory consolidation is driven by hippocampal replay of recent experiences. This replay triggers upstream reverberations with activity patterns that resemble those evoked by the original experience. In this study, we attempted to decode these reverberations in order to predict the degree to which subjects consolidated specific, recently-learned information. We trained subjects to associate sound cues with lateralized movements, then used those sounds to selectively bias memory reactivation during slow-wave sleep (SWS). A comparison of the electroencephalographic (EEG) signal evoked by left-associated and right-associated sounds revealed a laterally asymmetric, cue-dependent neural response during sleep. We detected significant differences in post-nap recall accuracy for cued and uncued stimuli, implicating this cue-dependent signal in the consolidation process. However, we detected no significant relationship between signal asymmetry and the effect of the cues on post-nap recall.