Endogenous memory reactivation during sleep in humans is clocked by slow oscillation-spindle complexes

Research output: Contribution to journalArticlepeer-review


Colleges, School and Institutes

External organisations

  • Ludwig-Maximilians University Munich (LMU)


Sleep is thought to support memory consolidation via reactivation of prior experiences, with particular electrophysiological sleep signatures (slow oscillations (SOs) and sleep spindles) gating the information flow between relevant brain areas. However, empirical evidence for a role of endogenous memory reactivation (i.e., without experimentally delivered memory cues) for consolidation in humans is lacking. Here, we devised a paradigm in which participants acquired associative memories before taking a nap. Multivariate decoding was then used to capture endogenous memory reactivation during non-rapid eye movement (NREM) sleep in surface EEG recordings. Our results reveal reactivation of learning material during SO-spindle complexes, with the precision of SO-spindle coupling predicting reactivation strength. Critically, reactivation strength (i.e. classifier evidence in favor of the previously studied stimulus category) in turn predicts the level of consolidation across participants. These results elucidate the memory function of sleep in humans and emphasize the importance of SOs and spindles in clocking endogenous consolidation processes.


Original languageEnglish
Article number3112
JournalNature Communications
Issue number1
Publication statusPublished - 25 May 2021


  • Brain/physiology, Cues, Electroencephalography/methods, Female, Humans, Learning/physiology, Male, Memory/physiology, Memory Consolidation/physiology, Photic Stimulation, Polysomnography/methods, Psychomotor Performance/physiology, Sleep/physiology, Young Adult