Rest time boosts a child's memory, small study suggests
MONDAY, Sept. 23, 2013 (HealthDay News) -- In an era when the average preschool day is filled with must-do curriculum, a new study has found that afternoon naps are not a waste of time.
Instead, taking an afternoon snooze may actually improve a child's ability to learn by improving memory, a small study suggests.
In a typical day, preschoolers pack information gleaned from a day of ABCs, shape sorting and social interactions into the short-term storage areas of their brains, said Rebecca Spencer, lead study author and a neuroscientist at the University of Massachusetts, Amherst.
"A nap allows information to move from temporary storage to more permanent storage, from the hippocampus to the cortical areas of the brain," she said. "You've heard the phrase, 'You should sleep on it.' Well, that's what we're talking about: Children need to process some of the input from the day."
The study was published in the Sept. 23 to 27 issue of the journal Proceedings of the National Academy of Sciences.
Many of the nation's preschoolers put in longer days than do their working parents, arriving at school as early as 6:30 a.m. and getting picked up after 5 p.m., Spencer said. "We're all short on sleep, and the kid's sleep is affected by the parents' schedules," she said.
Yet preschools, especially those supported with public funds, are under pressure to fill the day with lessons designed to prepare students for the early years of elementary school, Spencer said.
She said hearing that public preschools in Massachusetts were no longer required to schedule naptime caused her concern. "There was no science behind that decision," she said. "Now our research has provided scientific evidence of the value of naps for preschoolers."
For the study, the researchers taught 40 children from six preschools in western Massachusetts a visual-spatial memory game in the morning. The children were asked to remember where nine to 12 different pictures were located on a grid.
During the afternoon, children were either encouraged to nap or to stay awake. Naps lasted about 80 minutes. Later in the afternoon and the following morning, delayed recall was tested among both groups -- children who were encouraged to sleep and those who were kept awake.
The researchers found that although the children performed similarly in the morning, when their retention was fresh, children forgot significantly more when they had not taken a nap. Those who had slept remembered 10 percent more than those who were kept awake. The next day, the kids who had napped the previous afternoon scored better than those who hadn't napped. The data showed that a child doesn't recover the memory benefit from nighttime sleep, the researchers said.
To better understand whether memories were actively processed during naps, the researchers took 14 preschoolers to a sleep lab for polysomnography, a sleep study that shows changes in the brain. The children took naps for about 70 minutes. The napping children showed signs of signals being sent to long-term memory from the brain's hippocampus.
"Thus, there was evidence of a cause-and effect relationship between signs that the brain is integrating new information and the memory benefit of a nap," Spencer said.
A pediatrician not associated with the study said the findings prove what physicians have known for years. "Everyone benefits from a nap," said Dr. Peter Richel, chief of pediatrics at Northern Westchester Hospital in Mount Kisco, N.Y. "Before this study, without any hard data, many pediatricians have encouraged napping just for general health, statistically less infection, fewer meltdowns and happiness."
Yet some parents resist the idea of naps, Richel said. "For those buying T-shirts for their 3-month-olds that say 'Yale,' this may be hard to accept," he said. Parents at both ends of the socioeconomic spectrum may find it hard to value downtime in a busy schedule, he added.
Spencer said naps need to be put back into the preschool day, and she wants to see exploration of ways to enhance the napping experience -- with darkened rooms and comfortable cots or pads, for example.
The bottom line? "Naps are not wasted time," Spencer said.
Learn more about children and sleep from the National Sleep Foundation (http://www.sleepfoundation.org/article/sleep-topics/children-and-sleep ).
SOURCES: Rebecca Spencer, Ph.D., neuroscientist and associate professor, department of psychology, University of Massachusetts, Amherst; Peter Richel, M.D., chief, pediatrics, Northern Westchester Hospital, Mount Kisco, N.Y.; September 23 to 27 Proceedings of the National Academy of Sciences, online