title: Memory reactivation during rapid eye movement sleep promotes its generalization and integration in cortical stores.
abstract: OBJECTIVE
  Memory reactivation appears to be a fundamental process in memory consolidation. In this study we tested the influence of memory reactivation during rapid eye movement (REM) sleep on memory performance and brain responses at retrieval in healthy human participants.
  
  
  METHODS
  Fifty-six healthy subjects (28 women and 28 men, age [mean ± standard deviation]: 21.6 ± 2.2 y) participated in this functional magnetic resonance imaging (fMRI) study.
  
  
  RESULTS
  Auditory cues were associated with pictures of faces during their encoding. These memory cues delivered during REM sleep enhanced subsequent accurate recollections but also false recognitions. These results suggest that reactivated memories interacted with semantically related representations, and induced new creative associations, which subsequently reduced the distinction between new and previously encoded exemplars. Cues had no effect if presented during stage 2 sleep, or if they were not associated with faces during encoding. Functional magnetic resonance imaging revealed that following exposure to conditioned cues during REM sleep, responses to faces during retrieval were enhanced both in a visual area and in a cortical region of multisensory (auditory-visual) convergence.
  
  
  CONCLUSIONS
  These results show that reactivating memories during REM sleep enhances cortical responses during retrieval, suggesting the integration of recent memories within cortical circuits, favoring the generalization and schematization of the information.
authors.affiliation: Cyclotron Research Centre.
authors.forename: Virginie
authors.initials: V
authors.lastname: Sterpenich
authors.affiliation: Cyclotron Research Centre.
authors.forename: Christina
authors.initials: C
authors.lastname: Schmidt
authors.affiliation: Cyclotron Research Centre.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Albouy
authors.affiliation: Cyclotron Research Centre.
authors.forename: Luca
authors.initials: L
authors.lastname: Matarazzo
authors.affiliation: Cyclotron Research Centre.
authors.forename: Audrey
authors.initials: A
authors.lastname: Vanhaudenhuyse
authors.affiliation: Cyclotron Research Centre.
authors.forename: Pierre
authors.initials: P
authors.lastname: Boveroux
authors.affiliation: Cyclotron Research Centre.
authors.forename: Christian
authors.initials: C
authors.lastname: Degueldre
authors.affiliation: Cyclotron Research Centre.
authors.forename: Yves
authors.initials: Y
authors.lastname: Leclercq
authors.affiliation: Cyclotron Research Centre.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Balteau
authors.affiliation: Cyclotron Research Centre ; Department of Cognitive Sciences, University of Liège, Liège, Belgium.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Collette
authors.affiliation: Cyclotron Research Centre.
authors.forename: André
authors.initials: A
authors.lastname: Luxen
authors.affiliation: Cyclotron Research Centre.
authors.forename: Christophe
authors.initials: C
authors.lastname: Phillips
authors.affiliation: Cyclotron Research Centre.
authors.forename: Pierre
authors.initials: P
authors.lastname: Maquet
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003213:Conditioning, Psychological; D003463:Cues; D004569:Electroencephalography; D004644:Emotions; D005149:Facial Expression; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D010775:Photic Stimulation; D012895:Sleep, REM / Q000502:physiology*; D013016:Sound; D055815:Young Adult
keywords: REM sleep; brain plasticity; conditioning; fMRI; memory consolidation