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Somnologie - Schlafforschung und Schlafmedizin

, Volume 9, Issue 3, pp 148–153 | Cite as

Influence of midday naps on declarative memory performance and motivation

  • Manuel Schabus
  • Kerstin Hödlmoser
  • Thomas Pecherstorfer
  • Gerhard Klösch
Article

Summary

Question of the study

In the current literature it is still matter of discussion in which ways sleep might be beneficial for memory consolidation/enhancement. Former studies successfully demonstrated that sleep after learning produces greater (procedural/implicit) memory enhancements than equal amounts of waking. As far as naps are concerned, only few studies have been published on this issue; with respect to the influence of naps on declarative/explicit memory performance, there is even a complete lack of empirical data.

Subjects and methods

To find out whether 60-min naps (time in bed) might have a positive effect on declarative memory performance, we tested 22 subjects aged between 19 and 30 years. Subjects were trained on a declarative word-pair association task (prior to sleep) and were tested (cued recall) before and after 1 h of midday napping.

Results

Overall performance was significantly greater after sleep than before the nap. The data indicated that only those participants entering slow wave sleep (M=18.23 min) during the nap showed memory enhancement thereafter. Furthermore, quantitative EEG analyses revealed strong positive associations of (occipital) theta activity during the nap with memory performance enhancement.

Conclusions

In conclusion, the present findings support the sleep-dependent memory consolidation hypothesis and extend its scope to declarative learning in short midday naps.

Keywords

sleep mood explicit learning consolidation sleep-dependent consolidation 

Der Einfluss von Mittagsschläfchen auf deklarative Gedächtnisleistung und Motivation

Zusammenfassung

Fragestellung

In der aktuellen Literatur wird nach wie vor diskutiert, ob und auf welche Art und Weise Gedächtniskonsolidierung bzw. Gedächtnisverbesserung von Schlaf profitiert. Vorangegangene experimentelle Befunde stützen die Hypothese, dass Schlaf-im Vergleich zu äquivalenten Wachphasen-unmittelbar nach dem Lernen die (prozedural/implizite) Gedächtnisleistung stärker verbessert. Zum Thema Mittagschlaf und Gedächtniskonsolidierung existieren kaum (publizierte) Studien, wobei empirische Daten zu deklarativ-explizitem Gedächtnis praktisch gänzlich fehlen.

Probanden und Methodik

Um zu untersuchen, ob ein 60-minütiges (Bettzeit) Nickerchen einen positiven Einfluß auf die deklarative Gedächtnisleistung hat, wurden 22 Versuchspersonen (Alter: 19–30 Jahre) getestet. Die Versuchspersonen trainierten vor dem Nickerchen eine deklarative Wortpaar-Assoziationsaufgabe und wurden jeweils unmittelbar nach dem Lernen bzw. nach einem einstündigen Nickerchen getestet (“cued recall”).

Ergebnisse

Insgesamt hatten die Versuchspersonen nach dem Nickerchen eine signifikant bessere Gedächtnisleistung. Es zeigte sich weiter, dass sich nur die Gedächtnisleistung jener Versuchspersonen verbesserte, deren Nickerchen auch Tiefschlaf (M=18,23 min) beinhaltete. Eine quantitative Analyse des Schlaf-EEGs zeigte zudem einen stark positiven Zusammenhang zwischen okzipitaler Theta-Aktivität und verbesserter Gedächtnisleistung.

Schlussfolgerungen

Die präsentierten Ergebnisse stützen die “schlafabhängige Gedächtniskonsolidierungshypothese” und erweitern diese um deklaratives Lernen während des Mittagschlafes.

Schlüsselwörter

Schlaf Nickerchen Stimmung Lernen explizit Konsolidierung Gedächtnis 

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Copyright information

© Blackwell Verlag 2005

Authors and Affiliations

  • Manuel Schabus
    • 1
  • Kerstin Hödlmoser
    • 1
  • Thomas Pecherstorfer
    • 1
  • Gerhard Klösch
    • 2
  1. 1.Department of Physiological PsychologyUniversity of SalzburgSalzburgAustria
  2. 2.Department of NeurologyMedical University of ViennaSalzburgAustria

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