Naps Nurture Growing Brains

Jennifer Couzin-Frankel in Science:
NapFew features of child-rearing occupy as much parental brain space as sleep, and with it the timeless question: Is my child getting enough? Despite the craving among many parents for more sleep in their offspring (and, by extension, themselves), the purpose that sleep serves in young kids remains something of a mystery—especially when it comes to daytime naps. Do they help children retain information, as overnight sleep has been found to do in adults? A study published today in the Proceedings of the National Academy of Sciences provides the first evidence that daytime sleep is critical for effective learning in young children.

Psychologist Rebecca Spencer of the University of Massachusetts (UMass), Amherst, had more than a passing interest in the subject: Her daughters were 3 and 5 when she began chasing answers to these questions. She also wondered about growing enthusiasm for universal public preschool, where teachers don’t necessarily place much emphasis on naps. “There is a lot of science” about the best curriculum for preschool classrooms, “but nothing to protect the nap,” Spencer says. Still, data to support a nap’s usefulness were scarce: Studies in adults have found that sleep helps consolidate memories and learning, but whether the same is true of brief naps in the preschool set was unknown. So Spencer approached the first preschool she could think of that might help her find out: her daughters’. She later added other local preschools to her sample, for a total of 40 children ranging from nearly 3 to less than 6 years old. The goal of Spencer, her graduate student Laura Kurdziel, and undergraduate Kasey Duclos of Commonwealth Honors College at UMass, was to compare each child against him or herself: How well did a child learn when she napped, and what happened when she didn’t?

To test this, the trio first taught the children a variant of the popular game Memory or Concentration. They were shown a series of cards with pictures on them, such as a cat or umbrella. The cards were then flipped over, hiding the pictures. Each child was offered another picture card and asked to recall where in the matrix its match lay. Then, about 2 hours later, it was naptime—or nap-free time, depending. Kurdziel and Duclos developed various “nap promotion” techniques, resting a hand on a child’s back, rubbing their feet (this was surprisingly effective), or simply sitting next to them. “If they know that someone’s got their eye on them then they can’t wiggle around as much,” Spencer says. The average nap was about an hour and 15 minutes. Soon after the children woke up, the memory game was repeated. On a different day, they learned the game in the morning, were deprived of a nap, and then tested again. All participants repeated the memory game the next morning, too. A nap made a notable difference in how the preschoolers performed, especially among those who were used to getting one.

More here.