Declarative memory consolidation in humans: A prospective functional magnetic resonance imaging study
- A. Takashima†,‡,
- K. M. Petersson†,
- F. Rutters†,
- I. Tendolkar†,§,
- O. Jensen†,
- M. J. Zwarts¶,
- B. L. McNaughton∥, and
- G. Fernández†,††
- †F. C. Donders Center, and Departments of §Psychiatry, ¶Clinical Neurophysiology, and ††Neurology, Radboud University Nijmegen, P.O. Box 9101, 6500HB, Nijmegen, The Netherlands; and ∥Division of Neural Systems, University of Arizona, Room 384, Life Sciences North Building, Tucson, AZ 85724
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Edited by James L. McClelland, Carnegie Mellon University, Pittsburgh, PA, and approved November 13, 2005 (received for review September 6, 2005)
Abstract
Retrieval of recently acquired declarative memories depends on the hippocampus, but with time, retrieval is increasingly sustainable by neocortical representations alone. This process has been conceptualized as system-level consolidation. Using functional magnetic resonance imaging, we assessed over the course of three months how consolidation affects the neural correlates of memory retrieval. The duration of slow-wave sleep during a nap/rest period after the initial study session and before the first scan session on day 1 correlated positively with recognition memory performance for items studied before the nap and negatively with hippocampal activity associated with correct confident recognition. Over the course of the entire study, hippocampal activity for correct confident recognition continued to decrease, whereas activity in a ventral medial prefrontal region increased. These findings, together with data obtained in rodents, may prompt a revision of classical consolidation theory, incorporating a transfer of putative linking nodes from hippocampal to prelimbic prefrontal areas.
Footnotes
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↵ ‡ To whom correspondence should be addressed. E-mail: atsuko.takashima{at}fcdonders.ru.nl.
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Conflict of interest statement: No conflicts declared.
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This paper was submitted directly (Track II) to the PNAS office.
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Abbreviations: fMRI, functional magnetic resonance imaging; n.s., not significant; SVC, small volume corrected.
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Data deposition: The neuroimaging data have been deposited with the fMRI Data Center, www.fmridc.org (accession no. 2-2005-12ON7).
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See Commentary on page 509.
- Copyright © 2006, The National Academy of Sciences
