title: Daytime sleep has no effect on the time course of motor sequence and visuomotor adaptation learning.
abstract: Sleep has previously been claimed to be essential for the continued learning processes of declarative information as well as procedural learning. This study was conducted to examine the importance of sleep, especially the effects of midday naps, on motor sequence and visuomotor adaptation learning. Thirty-five (27 females) healthy, young adults aged between 18 and 30years of age participated in the current study. Addressing potential differences in explicit sequence and motor adaptation learning participants were asked to learn both, a nine-element explicit sequence and a motor adaptation task, in a crossover fashion on two consecutive days. Both tasks were performed with their non-dominant left hand. Prior to learning, each participant was randomized to one of three interventions; (1) power nap: 10-20min sleep, (2) long nap: 50-80min sleep or (3) a 45-min wake-condition. Performance of the motor learning task took place prior to and after a midday rest period, as well as after a night of sleep. Both sleep conditions were dominated by Stage N2 sleep with embedded sleep spindles, which have been described to be associated with enhancement of motor performance. Significant performance changes were observed in both tasks across all interventions (sleep and wake) confirming that learning took place. In the present setup, the magnitude of motor learning was not sleep-dependent in young adults - no differences between the intervention groups (short nap, long nap, no nap) could be found. The effect of the following night of sleep was not influenced by the previous midday rest or sleep period. This finding may be related to the selectiveness of the human brain enhancing especially memory being thought of as important in the future. Previous findings on motor learning enhancing effects of sleep, especially of daytime sleep, are challenged.
authors.affiliation: BrainImaging and NeuroStimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
authors.forename: Winifried
authors.initials: W
authors.lastname: Backhaus
authors.affiliation: BrainImaging and NeuroStimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
authors.forename: Hanna
authors.initials: H
authors.lastname: Braaß
authors.affiliation: Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany; Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, SE-171 76 Stockholm, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Renné
authors.affiliation: University Sleep Medicine Center Hamburg, A Cooperation of the University Medical Center Hamburg-Eppendorf and the Agaplesion Hospital, Falkenried 88, 20251 Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Krüger
authors.affiliation: BrainImaging and NeuroStimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Gerloff
authors.affiliation: BrainImaging and NeuroStimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany; University Sleep Medicine Center Hamburg, A Cooperation of the University Medical Center Hamburg-Eppendorf and the Agaplesion Hospital, Falkenried 88, 20251 Hamburg, Germany. Electronic address: f.hummel@uke.de.
authors.forename: Friedhelm C
authors.initials: FC
authors.lastname: Hummel
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D055815:Young Adult
keywords: Consolidation; Learning; Motor adaptation; Napping; Sequence; Sleep