title: Morning rapid eye movement sleep naps facilitate broad access to emotional semantic networks.
abstract: OBJECTIVE
  The goal of the study was to assess semantic priming to emotion and nonemotion cue words using a novel measure of associational breadth for participants who either took rapid eye movement (REM) or nonrapid eye movement (NREM) naps or who remained awake; assess relation of priming to REM sleep consolidation and REM sleep inertia effects.
  
  
  METHODS
  The associational breadth task was applied in both a priming condition, where cue-words were signaled to be memorized prior to sleep (primed), and a nonpriming condition, where cue words were not memorized (nonprimed). Cue words were either emotional (positive, negative) or nonemotional. Participants were randomly assigned to either an awake (WAKE) or a sleep condition, which was subsequently split into NREM or REM groups depending on stage at awakening.
  
  
  METHODS
  Hospital-based sleep laboratory.
  
  
  METHODS
  Fifty-eight healthy participants (22 male) ages 18 to 35 y (Mage = 23.3 ± 4.08 y).
  
  
  RESULTS
  The REM group scored higher than the NREM or WAKE groups on primed, but not nonprimed emotional cue words; the effect was stronger for positive than for negative cue words. However, REM time and percent correlated negatively with degree of emotional priming. Priming occurred for REM awakenings but not for NREM awakenings, even when the latter sleep episodes contained some REM sleep.
  
  
  CONCLUSIONS
  Associational breadth may be selectively consolidated during REM sleep for stimuli that have been tagged as important for future memory retrieval. That priming decreased with REM time and was higher only for REM sleep awakenings is consistent with two explanatory REM sleep processes: REM sleep consolidation serving emotional downregulation and REM sleep inertia.
authors.affiliation: Dream and Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, Canada.|Department of Biomedical Sciences, Université de Montréal, Montréal, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Carr
authors.affiliation: Dream and Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, Canada.|Department of Psychiatry, Université de Montréal, Montréal, Canada.
authors.forename: Tore
authors.initials: T
authors.lastname: Nielsen
mesh_terms: D000293:Adolescent; D000328:Adult; D003463:Cues; D004644:Emotions; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D012660:Semantics; D012890:Sleep / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology*; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology; D055815:Young Adult
keywords: NREM sleep; REM sleep; associational processes; emotion; memory; naps