title: Overnight improvements in two REM sleep-sensitive tasks are associated with both REM and NREM sleep changes, sleep spindle features, and awakenings for dream recall.
abstract: Memory consolidation is associated with sleep physiology but the contribution of specific sleep stages remains controversial. To clarify the contribution of REM sleep, participants were administered two REM sleep-sensitive tasks to determine if associated changes occurred only in REM sleep. Twenty-two participants (7 men) were administered the Corsi Block Tapping and Tower of Hanoi tasks prior to and again after a night of sleep. Task improvers and non-improvers were compared for sleep structure, sleep spindles, and dream recall. Control participants (N = 15) completed the tasks twice during the day without intervening sleep. Overnight Corsi Block improvement was associated with more REM sleep whereas Tower of Hanoi improvement was associated with more N2 sleep. Corsi Block improvement correlated positively with %REM sleep and Tower of Hanoi improvement with %N2 sleep. Post-hoc analyses suggest Tower of Hanoi effects-but not Corsi Block effects-are due to trait differences. Sleep spindle density was associated with Tower of Hanoi improvement whereas spindle amplitude correlated with Corsi Block improvement. Number of REM awakenings for dream reporting (but not dream recall per se) was associated with Corsi Block, but not Tower of Hanoi, improvement but was confounded with REM sleep time. This non-replication of one of 2 REM-sensitive task effects challenges both 'dual-process' and 'sequential' or 'sleep organization' models of sleep-dependent learning and points rather to capacity limitations on REM sleep. Experimental awakenings for sampling dream mentation may not perturb sleep-dependent learning effects; they may even enhance them.
authors.affiliation: Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada; Department of Psychiatry, Université de Montréal, Canada. Electronic address: tore.nielsen@umontreal.ca.
authors.forename: T
authors.initials: T
authors.lastname: Nielsen
authors.affiliation: Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada.
authors.forename: C
authors.initials: C
authors.lastname: O'Reilly
authors.affiliation: Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada; Department of Biomedical Sciences, Université de Montréal, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Carr
authors.affiliation: Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada; Department of Psychology, Université de Montréal, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Dumel
authors.affiliation: Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada; Department of Psychology, Université de Montréal, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Godin
authors.affiliation: Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada; Department of Biomedical Sciences, Université de Montréal, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Solomonova
authors.affiliation: Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada; Department of Psychology, Université de Montréal, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Lara-Carrasco
authors.affiliation: Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada; Department of Psychology, Université de Montréal, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Blanchette-Carrière
authors.affiliation: Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Paquette
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology; D004325:Dreams / Q000502:physiology; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D000069077:Memory Consolidation / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests; D012894:Sleep Stages; D012895:Sleep, REM / Q000502:physiology*; D055815:Young Adult
keywords: Dreaming; NREM sleep; REM sleep; Sleep spindles; Visuospatial memory consolidation