title: Tactile stimulation during sleep alters slow oscillation and spindle densities but not motor skill.
abstract: Studies using targeted memory reactivation have shown that presentation of auditory or olfactory contextual cues during sleep can bias hippocampal reactivations towards the preferential replay of the cue-associated material, thereby resulting in enhanced consolidation of that information. If the same cortical ensembles are indeed used for encoding and storage of a given piece of information, forcing the sleeping brain to re-engage in task-intrinsic information processing should disturb the natural ongoing consolidation processes and therefore impair possible sleep benefits. Here we aimed at recreating an integral part of the sensory experience of a motor skill in a daytime nap, by means of a tactile stimulation. We hypothesized that tampering with the tactile component of a motor skill during sleep would result in hindered performance at retest, due to interference between the highly congruent incoming stimuli and the core skill trace. Contrary to our predictions, the tactile stimulation did not influence neither speed nor accuracy, when compared to natural sleep. However, an exploratory sleep EEG analysis revealed stimulation-induced alterations in the abundance and cortical topography of slow oscillations and spindles. These findings suggest that despite the lack of a significant effect on motor behavior, tactile stimulation induced changes in EEG features suggestive of a possible uncoupling between the sleep oscillations thought to underlie consolidation processes, i.e. slow oscillations and sleep spindles.
authors.affiliation: Human Chronobiology Laboratory, Department of Physiology, Federal University of Paraná, 81531-990 Curitiba, Paraná, Brazil. Electronic address: sofia@ufpr.br.
authors.forename: Sofia Isabel Ribeiro
authors.initials: SI
authors.lastname: Pereira
authors.affiliation: Human Chronobiology Laboratory, Department of Physiology, Federal University of Paraná, 81531-990 Curitiba, Paraná, Brazil.
authors.forename: Felipe
authors.initials: F
authors.lastname: Beijamini
authors.affiliation: Institute of Medical Psychology and Behavioral Neurobiology, Department of Medical Psychology, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Frederik D
authors.initials: FD
authors.lastname: Weber
authors.affiliation: Human Chronobiology Laboratory, Department of Physiology, Federal University of Paraná, 81531-990 Curitiba, Paraná, Brazil.
authors.forename: Roberta Almeida
authors.initials: RA
authors.lastname: Vincenzi
authors.affiliation: Human Chronobiology Laboratory, Department of Physiology, Federal University of Paraná, 81531-990 Curitiba, Paraná, Brazil.
authors.forename: Felipe Augusto Cini
authors.initials: FA
authors.lastname: da Silva
authors.affiliation: Human Chronobiology Laboratory, Department of Physiology, Federal University of Paraná, 81531-990 Curitiba, Paraná, Brazil.
authors.forename: Fernando Mazzilli
authors.initials: FM
authors.lastname: Louzada
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D058256:Brain Waves / Q000502:physiology*; D004569:Electroencephalography; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D010507:Periodicity; D010812:Physical Stimulation; D012890:Sleep / Q000502:physiology*; D013057:Spectrum Analysis; D014110:Touch / Q000502:physiology*; D055815:Young Adult
keywords: Finger tapping task; Sleep; Sleep spindles; Slow oscillations; Tactile stimulation; Targeted memory reactivation