Sleep spindles in midday naps enhance learning in preschool children

Sleep spindles in midday naps enhance learning in preschool children

1. Laura Kurdziel^a,
2. Kasey Duclos^b,^c, and
3. Rebecca M. C. Spencer^a,^b,¹

Author Affiliations

1. Edited by Terrence J. Sejnowski, Salk Institute for Biological Studies, La Jolla, CA, and approved August 19, 2013 (received for review April 5, 2013)

Significance

Lacking scientific understanding of the function of naps in early childhood, policy makers may curtail preschool classroom nap opportunities due to increasing curriculum demands. Here we show evidence that classroom naps support learning in preschool children by enhancing memories acquired earlier in the day as compared with equivalent intervals spent awake.

Abstract

Despite the fact that midday naps are characteristic of early childhood, very little is understood about the structure and function of these sleep bouts. Given that sleep benefits memory in young adults, it is possible that naps serve a similar function for young children. However, children transition from biphasic to monophasic sleep patterns in early childhood, eliminating the nap from their daily sleep schedule. As such, naps may contain mostly light sleep stages and serve little function for learning and memory during this transitional age. Lacking scientific understanding of the function of naps in early childhood, policy makers may eliminate preschool classroom nap opportunities due to increasing curriculum demands. Here we show evidence that classroom naps support learning in preschool children by enhancing memories acquired earlier in the day compared with equivalent intervals spent awake. This nap benefit is greatest for children who nap habitually, regardless of age. Performance losses when nap-deprived are not recovered during subsequent overnight sleep. Physiological recordings of naps support a role of sleep spindles in memory performance. These results suggest that distributed sleep is critical in early learning; when short-term memory stores are limited, memory consolidation must take place frequently.

• development
• education

Footnotes

• ¹To whom correspondence should be addressed. E-mail: rspencer@psych.umass.edu.

• Author contributions: R.M.C.S. designed research; L.K., K.D., and R.M.C.S. performed research; L.K., K.D., and R.M.C.S. analyzed data; and L.K. and R.M.C.S. wrote the paper.
• The authors declare no conflict of interest.
• This article is a PNAS Direct Submission.

Freely available online through the PNAS open access option.