It may not look like much is going on during naptime in preschool, but dozing youngsters are actually busy learning.
A lot is happening in the brain of a slumbering preschooler, including processing and storing memories that are the foundation for learning. That makes naptime as important as programs focused on fighting bullying or learning to wait their turn for academe’s youngest students, according to the latest research.
Reporting in the Proceedings of the National Academy of Sciences, Rebecca Spencer, associate professor of psychology and neuroscience at the University of Massachusetts Amherst, says that napping should be part of any preschool curriculum. In her study, Spencer and her colleagues taught 40 preschoolers a version of the Memory matching game in which pairs of covered pictures were placed in a grid and the children had to uncover and remember the location of the pictures in order to match identical paired images. The first time the children played the game, they were allowed to nap for about 77 minutes afterward, and then asked to play the game again. The next week, the same kids were asked to repeat the process, except this time the researchers kept the children awake instead of allowing them to sleep.
Skipping the nap led to a 10% drop in the children’s accuracy in the memory-based game. Even after Spencer adjusted for the fact that the napless kids may have been more tired and distracted – by having them play the game again 24 hours later, after a good night’s sleep – the relationship between naps and better performance on the test remained strong. And the kids who napped regularly consistently did better than the kids who did not nap as part of their daily routine.
“These results should give schools, center directors and policy makers motivation to not only preserve nap opportunities but to focus on encouraging nap opportunities,” says Spencer.
Previous work suggests why naps might boost cognitive performance. During sleep, scientists believe that memories are made, or processed in ways that make it easier for the brain to access and retrieve later. Experiences and sensations are processed in the hippocampus, which creates short term memories, but in order to make room for the barrage of new material that floods in every minute, the brain continues to work while we sleep, filing these memories away into long term storage to free up the hippocampus for new experiences.
To verify her findings, Spencer also studied another group of 14 preschoolers who played the same matching game, both with a nap and without a nap, and hooked them up to electrodes to monitor their brain activity while they slept overnight in the lab. How long the children slept didn’t affect their accuracy in the game. What mattered more was a pattern brain activity that in animal models is connected to a more active hippocampus and memory formation. The more plastic, or open to new memories the child’s brain was, the better he performed in the game.
Interestingly, Spencer did not find much REM sleep — which sleep phase that in older children and adults is associated with the processing of emotions — among the napping kids. She suspects that for storing declarative memories such as those required in the matching game, REM sleep probably isn’t necessary.
With President Obama advocating universal preschool to take advantage of a developing brain’s hunger to observe, learn and process new information, these results should justify the need for naps as part of a preschool curriculum. “Currently some kids who have the most social and academic needs are taken out of the classroom for one-on-one sessions with teachers during the nap,” says Spencer. “But these could be the kids who need the nap the most. Naps should be part of our academic goals – they actually help us to meet academic goals.”