title: Slow oscillation amplitudes and up-state lengths relate to memory improvement.
abstract: There is growing evidence of the active involvement of sleep in memory consolidation. Besides hippocampal sharp wave-ripple complexes and sleep spindles, slow oscillations appear to play a key role in the process of sleep-associated memory consolidation. Furthermore, slow oscillation amplitude and spectral power increase during the night after learning declarative and procedural memory tasks. However, it is unresolved whether learning-induced changes specifically alter characteristics of individual slow oscillations, such as the slow oscillation up-state length and amplitude, which are believed to be important for neuronal replay. 24 subjects (12 men) aged between 20 and 30 years participated in a randomized, within-subject, multicenter study. Subjects slept on three occasions for a whole night in the sleep laboratory with full polysomnography. Whereas the first night only served for adaptation purposes, the two remaining nights were preceded by a declarative word-pair task or by a non-learning control task. Slow oscillations were detected in non-rapid eye movement sleep over electrode Fz. Results indicate positive correlations between the length of the up-state as well as the amplitude of both slow oscillation phases and changes in memory performance from pre to post sleep. We speculate that the prolonged slow oscillation up-state length might extend the timeframe for the transfer of initial hippocampal to long-term cortical memory representations, whereas the increase in slow oscillation amplitudes possibly reflects changes in the net synaptic strength of cortical networks.
authors: Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, University of Salzburg, Salzburg, Austria.
authors: Dominik P J
authors: DP
authors: Heib
authors: Kerstin
authors: K
authors: Hoedlmoser
authors: Peter
authors: P
authors: Anderer
authors: Josef
authors: J
authors: Zeitlhofer
authors: Georg
authors: G
authors: Gruber
authors: Wolfgang
authors: W
authors: Klimesch
authors: Manuel
authors: M
authors: Schabus
mesh_terms: D000328:Adult; D001519:Behavior; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall; D009483:Neuropsychological Tests; D012890:Sleep / Q000502:physiology*; D055815:Young Adult