Cited by 139Sleep and Wakefulness ResearchMemory and Neural MechanismsMemory Processes and Influences

Sleep-Dependent Facilitation of Episodic Memory Details

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van der Helm, Els, Gujar, Ninad, Nishida, Masaki, Walker, Matthew P.·2011·PLoS ONE

Abstract

While a role for sleep in declarative memory processing is established, the qualitative nature of this consolidation benefit, and the physiological mechanisms mediating it, remain debated. Here, we investigate the impact of sleep physiology on characteristics of episodic memory using an item- (memory elements) and context- (contextual details associated with those elements) learning paradigm; the latter being especially dependent on the hippocampus. Following back-to-back encoding of two word lists, each associated with a different context, participants were assigned to either a Nap-group, who obtained a 120-min nap, or a No Nap-group. Six hours post-encoding, participants performed a recognition test involving item-memory and context-memory judgments. In contrast to item-memory, which demonstrated no between-group differences, a significant benefit in context-memory developed in the Nap-group, the extent of which correlated both with the amount of stage-2 NREM sleep and frontal fast sleep-spindles. Furthermore, a difference was observed on the basis of word-list order, with the sleep benefit and associated physiological correlations being selective for the second word-list, learned last (most proximal to sleep). These findings suggest that sleep may preferentially benefit contextual (hippocampal-dependent) aspects of memory, supported by sleep-spindle oscillations, and that the temporal order of initial learning differentially determines subsequent offline consolidation.

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Crossref · 10.1371/journal.pone.0027421

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  • In children and adults, spindle number and density strongly correlate with IQ scores and overnight retention of memories.

    “In children and adults, spindle number and density strongly correlate with IQ scores (106, 395, 439, 847, 1038, 1039) as well as overnight retention of memories (213, 1057, 1230).”

    From About Sleep's Role in Memory (2013) · cites this paper as [1230]

    The Results section ('Memory performance and sleep-spindle associations'; page unavailable) reports that fast spindle count correlated with context-memory retention in the nap group. Another Results passage reports that the correlation with spindle density was not significant (r = 0.37, P = 0.26). This paper's finding concerns retention after a nap, not overnight retention; the citations attached to IQ scores are separate from the citations attached to memory retention. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • Compared with item memory, context memory is particularly sensitive to beneficial effects of sleep.

    “In addition, some human studies revealed that, compared with item memory, context memory, a core function of the hippocampus, is particularly sensitive to the beneficial effects of sleep (602,732,1128,1230).”

    From About Sleep's Role in Memory (2013) · cites this paper as [1230]

  • Spindles (13-15 Hz) during a postlearning nap predicted sleep-dependent memory improvement for contextual aspects of episodic memories known to most closely depend on hippocampal function.

    “Moreover, spindles (13-15 Hz) during a postlearning nap predicted sleepdependent memory improvement for contextual aspects of episodic memories known to most closely depend on the hippocampal function (1230).”

    From About Sleep's Role in Memory (2013) · cites this paper as [1230]

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Research works printed but not linked: 3

  1. [6]Walker MP Stickgold R 2010 Overnight alchemy: sleep-dependent memory evolution. Nat Rev Neurosci 11 218; author reply 218 20168316 PMC2891532
  2. [64]Nishida M Walker M 2007 Daytime naps, motor memory consolidation and regionally specific sleep spindles. PLoS ONE 2 e341 17406665 PMC1828623
  3. [72]Clemens Z Fabo D Halasz P 2006 Twenty-four hours retention of visuospatial memory correlates with the number of parietal sleep spindles. Neurosci Lett 403 52 56 16714084

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Authors
van der Helm, E., Gujar, N., Nishida, M., & Walker, M. P.
Affiliations
  • University of California, Berkeley (US)
  • Tokyo Medical and Dental University (JP)
Corresponding author
Walker, Matthew P.
Venue
PLoS ONE
Published
2011-11-17
Volume
6
Issue
11
Pages
e27421
ISSN
1932-6203 (ISSN-L)
OpenAlex
W2150174546
Cited by
138
References
83
Citations by year
2025: 5 · 2024: 7 · 2023: 5 · 2022: 8 · 2021: 12 · 2020: 9 · 2019: 11 · 2018: 8 · 2017: 12 · 2016: 7 · 2015: 11 · 2014: 15 · 2013: 18 · 2012: 8
FWCI
6.65
Type
journal article
Language
en
Open access
Locations
  • PLoS ONE (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
  • Figshare (submittedVersion, cc-by)
Funders
  • National Institutes of Health
  • National Institute on Aging (R01AG031164)
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Sleep and Wakefulness Research
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Memory and Neural Mechanisms
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Memory Processes and Influences
Keywords
sleep-dependent memory consolidation, episodic memory, contextual memory, item memory, hippocampus, NREM sleep, sleep spindles, frontal lobe, recognition memory, declarative memory
MeSH terms
Adolescent, Adult, Female, Hippocampus, Humans, Learning, Male, Sleep, Wakefulness, Young Adult, Memory, Episodic

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