title: Working memory is partially preserved during sleep.
abstract: Although several cognitive processes, including speech processing, have been studied during sleep, working memory (WM) has never been explored up to now. Our study assessed the capacity of WM by testing speech perception when the level of background noise and the sentential semantic length (SSL) (amount of semantic information required to perceive the incongruence of a sentence) were modulated. Speech perception was explored with the N400 component of the event-related potentials recorded to sentence final words (50% semantically congruent with the sentence, 50% semantically incongruent). During sleep stage 2 and paradoxical sleep: (1) without noise, a larger N400 was observed for (short and long SSL) sentences ending with a semantically incongruent word compared to a congruent word (i.e. an N400 effect); (2) with moderate noise, the N400 effect (observed at wake with short and long SSL sentences) was attenuated for long SSL sentences. Our results suggest that WM for linguistic information is partially preserved during sleep with a smaller capacity compared to wake.
authors.affiliation: CNRS, UMR5292, Lyon Neuroscience Research Center, Auditory Cognition and Psychoacoustics Team, Lyon, France. jerome.daltrozzo@gmail.com
authors.forename: Jérôme
authors.initials: J
authors.lastname: Daltrozzo
authors.forename: Léa
authors.initials: L
authors.lastname: Claude
authors.forename: Barbara
authors.initials: B
authors.lastname: Tillmann
authors.forename: Hélène
authors.initials: H
authors.lastname: Bastuji
authors.forename: Fabien
authors.initials: F
authors.lastname: Perrin
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology