title: Sleep stage II contributes to the consolidation of declarative memories.
abstract: Various studies suggest that non-rapid eye movement (NREM) sleep, especially slow-wave sleep (SWS), is vital to the consolidation of declarative memories. However, sleep stage 2 (S2), which is the other NREM sleep stage besides SWS, has gained only little attention. The current study investigated whether S2 during an afternoon nap contributes to the consolidation of declarative memories. Participants learned associations between faces and cities prior to a brief nap. A cued recall test was administered before and following the nap. Spindle, delta and slow oscillation activity was recorded during S2 in the nap following learning and in a control nap. Increases in spindle activity, delta activity, and slow oscillation activity in S2 in the nap following learning compared to the control nap were associated with enhanced retention of face-city associations. Furthermore, spindles tended to occur more frequently during up-states than down-states within slow oscillations during S2 following learning versus S2 of the control nap. These findings suggest that spindles, delta waves, and slow oscillations might promote memory consolidation not only during SWS, as shown earlier, but also during S2.
authors: Department of Psychology, University of Bern, Switzerland.
authors: Simon
authors: S
authors: Ruch
authors: Oliver
authors: O
authors: Markes
authors: Simone B
authors: SB
authors: Duss
authors: Daniel
authors: D
authors: Oppliger
authors: Thomas P
authors: TP
authors: Reber
authors: Thomas
authors: T
authors: Koenig
authors: Johannes
authors: J
authors: Mathis
authors: Corinne
authors: C
authors: Roth
authors: Katharina
authors: K
authors: Henke
mesh_terms: D000328:Adult; D001244:Association; D003700:Delta Rhythm / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D009483:Neuropsychological Tests; D017286:Polysomnography / Q000295:instrumentation / Q000379:methods*; D012894:Sleep Stages / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult