title: Interindividual sleep spindle differences and their relation to learning-related enhancements.
abstract: We reported earlier that overnight change in explicit memory is positively related to the change in sleep spindle activity (between a control and a learning night). However, it remained unclear whether this effect was restricted to good memory performers and whether a general association of sleep spindles and a "sleep-related learning trait" may not account for this effect. Here we now present a secondary and more detailed analysis of our randomized multicenter study. Subjects were studied over a 4-week study period (including actigraphy and daily sleep diaries), including three overnight stays in the sleep laboratory. In the course of the study, subjects completed test-batteries of memory (Wechsler-Memory-Scale-revised; WMS) and other cognitive abilities (Raven's Advanced-Progressive-Matrices; APM) and were asked to study 160 word pairs in the evening before being tested by cued-recall. Afterwards, subjects went to bed in the laboratory with full polysomnographic montages. Additionally, subjects participated on another occasion in a non-learning control (perceptual priming) task that was counterbalanced either before or after the learning condition. Slow as well as fast spindle activities were analyzed at frontopolar and central topographies. Although it was found that spindle activity is generally (in learning as well as control nights) elevated in highly gifted subjects, spindle analyses revealed that spindle increase (control to learning night) is specifically related to explicit memory improvement overnight, independent of individual learning traits. Together these findings suggest that the spindle increase after learning is related to elaborate encoding before sleep, whereas an individual's general learning ability is well reflected in interindividual (and trait-like) differences of absolute sleep spindle activity.
authors.affiliation: Department of Physiological Psychology, University of Salzburg, Austria. manuel.schabus@sbg.ac.at
authors.forename: Manuel
authors.initials: M
authors.lastname: Schabus
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hoedlmoser
authors.forename: Thomas
authors.initials: T
authors.lastname: Pecherstorfer
authors.forename: Peter
authors.initials: P
authors.lastname: Anderer
authors.forename: Georg
authors.initials: G
authors.lastname: Gruber
authors.forename: Silvia
authors.initials: S
authors.lastname: Parapatics
authors.forename: Cornelia
authors.initials: C
authors.lastname: Sauter
authors.forename: Gerhard
authors.initials: G
authors.lastname: Kloesch
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Klimesch
authors.forename: Bernd
authors.initials: B
authors.lastname: Saletu
authors.forename: Josef
authors.initials: J
authors.lastname: Zeitlhofer
mesh_terms: D000328:Adult; D001245:Association Learning / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007206:Individuality; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D017286:Polysomnography; D012016:Reference Values; D012890:Sleep / Q000502:physiology*; D014706:Verbal Learning / Q000502:physiology*