Researchers are exploring whether these ubiquitous fluorinated molecules might worsen infections or hamper vaccine effectiveness.
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Edited by H. Craig Heller, Stanford University, Stanford, CA, and accepted by the Editorial Board December 16, 2014 (received for review July 23, 2014)
Significance
The potential benefits of infant sleep for memory processing are largely unexplored. Here we show evidence that having an extended nap (≥30 min) within 4 h of learning helps 6- and 12-month-old infants to retain their memories for new behaviors across a 4- and 24-h delay. These results suggest that infants rely on frequent naps for the formation of long-term memories.
Abstract
Human infants devote the majority of their time to sleeping. However, very little is known about the role of sleep in early memory processing. Here we test 6- and 12-mo-old infants’ declarative memory for novel actions after a 4-h [Experiment (Exp.) 1] and 24-h delay (Exp. 2). Infants in a nap condition took an extended nap (≥30 min) within 4 h after learning, whereas infants in a no-nap condition did not. A comparison with age-matched control groups revealed that after both delays, only infants who had napped after learning remembered the target actions at the test. Additionally, after the 24-h delay, memory performance of infants in the nap condition was significantly higher than that of infants in the no-nap condition. This is the first experimental evidence to our knowledge for an enhancing role of sleep in the consolidation of declarative memories in the first year of life.
Footnotes
- ↵1To whom correspondence should be addressed. Email: sabine.seehagen{at}rub.de.
Author contributions: S. Seehagen, J.S.H., and S. Schneider designed research; S. Seehagen and C.K. performed research; S. Seehagen and C.K. analyzed data; and S. Seehagen, C.K., J.S.H., and S. Schneider wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission. H.C.H. is a guest editor invited by the Editorial Board.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1414000112/-/DCSupplemental.
Sleep serves memory consolidation in infants
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