title: Timing matters: open-loop stimulation does not improve overnight consolidation of word pairs in humans.
abstract: The application of auditory clicks during non-rapid eye movement (NREM) sleep phase-locked to the up state of the slow oscillation (closed-loop stimulation) has previously been shown to enhance the consolidation of declarative memories. We designed and applied sequences of three clicks during deep NREM sleep to achieve a quasi-phase-dependent open-loop stimulation. This stimulation was successful in eliciting slow oscillation power in the stimulation period. Although fast and slow spindle power were markedly decreased during the stimulation period, memory consolidation did not differ from control. During putative up states fast spindle power remained, however, at control levels. We conclude that concurrence of slow oscillations and fast spindles suffices to maintain memory consolidation at control levels despite an overall decreased spindle activity.
authors.affiliation: Institute for Neuro- and Bioinformatics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany. weigenand@inb.uni-luebeck.de.|Graduate School for Computing in Medicine and Life Science, University of Lübeck, Lübeck, Germany. weigenand@inb.uni-luebeck.de.
authors.forename: Arne
authors.initials: A
authors.lastname: Weigenand
authors.affiliation: Center for Brain, Behavior and Metabolism, University of Lübeck, Lübeck, Germany.|Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Mölle
authors.affiliation: Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
authors.forename: Friederike
authors.initials: F
authors.lastname: Werner
authors.affiliation: Institute for Neuro- and Bioinformatics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.|Graduate School for Computing in Medicine and Life Science, University of Lübeck, Lübeck, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Martinetz
authors.affiliation: Graduate School for Computing in Medicine and Life Science, University of Lübeck, Lübeck, Germany. lisa.marshall@pharma.uni-luebeck.de.|Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany. lisa.marshall@pharma.uni-luebeck.de.
authors.forename: Lisa
authors.initials: L
authors.lastname: Marshall
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D009483:Neuropsychological Tests; D017286:Polysomnography / Q000379:methods; D012890:Sleep / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
keywords: memory; sleep; slow oscillations; spindles; thalamocortical system