Pre-sleep experiences shape neural activity and dream content in the sleeping brain

Deniz Kumral; Jessica Palmieri; Steffen Gais; Monika Schönauer

doi:10.1016/j.isci.2025.113032

Pre-sleep experiences shape neural activity and dream content in the sleeping brain

iScience. 2025 Jul 1;28(8):113032. doi: 10.1016/j.isci.2025.113032. eCollection 2025 Aug 15.

Authors

Deniz Kumral^{1

2}, Jessica Palmieri¹, Steffen Gais³, Monika Schönauer^{1

2

4}

Affiliations

¹ Institute of Psychology, Neuropsychology, University of Freiburg, Freiburg im Breisgau, Germany.
² BrainLinks-BrainTools, University of Freiburg, Freiburg im Breisgau, Germany.
³ Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany.
⁴ Bernstein Center Freiburg, University of Freiburg, Freiburg im Breisgau, Germany.

Abstract

Dreams incorporate recent experiences, and memory-related brain activity is reactivated during sleep, suggesting that dreaming, memory consolidation, and reactivation are tightly linked. We devised a paradigm to investigate whether memory reprocessing during sleep contributes to dreaming. Participants listened to different audiobooks before falling asleep, introducing dissimilar experiences to be processed at night. We show that audiobook content was reprocessed at the neural level using multivariate pattern analyses. Brain activity during rapid eye movement sleep, particularly in the beta range, carried information about the audiobook. While the amount of neural reinstatement did not correlate with memory retention, global beta power during REM sleep was associated with better memory performance. Moreover, blind raters could determine which audiobook participants had studied based on dream reports. Participants who dreamt of the audiobook also showed stronger neural reinstatement. Reprocessing of pre-sleep experiences during sleep may thus shape our brain activity, our dreams, and our memories.

Keywords: EEG; REM sleep; biological sciences; clinical neuroscience; cognitive neuroscience; dreaming; memory reactivation; natural sciences; neuroscience; representational similarity analyses; sleep.