Sleep is an important part of child development, and in order to get enough sleep, children often nap in the afternoons. By the time they reach preschool, many (but not all) children have lost the need for this nap. According to new research performed by Dr. Rebecca Spencer, some children really do need an afternoon nap in order to learn.

To test the effect of napping on preschool children, Spencer had the children play a memory game in the morning. Then, during afternoon naptime, some children were encouraged to nap while others were encouraged to stay awake. After their nap, Spencer tested their memory again, and once more the following day after a full night’s sleep.

The results confirmed what child caretakers already knew: that many children need to nap in order to be at their full learning potential. Children accustomed to napping every day couldn’t function as well without one.

“For those that nap habitually, they lose 15 percent of what they learned in the morning when they don’t nap,” said Dr. Spencer, associate professor of psychology and neuroscience, in an interview with Healthline. “This forgetting is overcome when they nap.”

Interestingly, only some of the children needed an afternoon nap in order to perform as well on the memory test. For others, the nap made no difference in their scores. Having outgrown the need for an afternoon rest, the only effect the nap had was to make them feel a bit sleepy.

“Sleep is important not only for memory consolidation but also for cognitive development,” Sanjeev Kothare, M.D., Director of the Pediatric Sleep Program and a professor of neurology at the NYU Langone Medical Center and School of Medicine told Healthline. “The developing brain continues to grow very rapidly in the first two years to 90 percent of adult size. Cognitive development and memory consolidation, which occur during these developing years, are important functions enhanced by healthy sleep, including napping in the first five years.”

The Structure of Sleep

Spencer delved further into her study by having the preschool children take a nap in a sleep lab, where she could examine the architecture of their brain waves during sleep. She found that the duration of the nap didn’t predict the children’s memory scores at all. Nor did deep sleep, which is known to play a role in forming memories, nor REM sleep, the stage of sleep where dreaming most commonly occurs. Instead, she found that test scores were predicted by a brain wave signature called sleep spindles, which occur during light, non-REM sleep.

The more sleep spindles that appeared in the child’s brain waves during the nap, the better his or her memory score was in the afternoon. “Sleep spindles are associated with plasticity in the brain (i.e., moments when the brain is primed to form memories),” explained Spencer.

Even though not all preschool children require a nap, for those who do, the difference is drastic. This study casts doubt on some preschools’ decision to reduce napping hours in order to increase the amount of instruction the children receive.

“I think this is strong evidence that naps should not only be a part of the preschool routine but that [children] should be encouraged to nap,” she says. “While educators and policy makers focus on the academic goals of preschool, we demonstrate that napping assists in meeting those academic goals.”

Kothare offers additional advice. “Sleep regular hours, especially on weekends, avoid excessive caffeine, take plenty of sunlight in the morning, exercise and eat healthy, and avoid becoming overweight. See your doctor if your child snores, is sleepy in the day, or cannot sleep well at night.”

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Teach Your Children Well

Sleep isn’t the only factor that influences how children learn. Dr. Sarah Roseberry Lytle at Temple University in Philadelphia examined even younger children, ages two to two-and-a-half, to see how they learn best.

Dr. Roseberry took groups of toddlers and had them either live video chat with an instructor, or watch a pre-recorded video of an instructor who had interacted with another toddler. Then, the children learned nonsense words from either an in-person instructor or an instructor on video.

“We actually found no differences in toddlers' language learning in the video chat and live interaction conditions,” said Roseberry, a postdoctoral fellow at the University of Washington, in an interview with Healthline. “This doesn't necessarily mean that video chats are identical to live interactions, but we found equivalent learning in both situations with this particular task.”

So the screen isn’t the problem. Rather, it’s the passive nature of video instruction that makes children tune out. “Here, we specifically find that social contingency, or the back-and-forth responsiveness that exists in social interactions, is especially important,” Roseberry said.

Roseberry’s finding holds promise for the future of live video instruction for kids. “More and more research is emerging to suggest that children's ability to learn from screen media has nothing to do with the screens themselves, but rather the type of information, activity, and interaction that the screen affords,” she explained.

"When screens allow for socially contingent, responsive, and back-and-forth interactions, we see that they can be a powerful learning tool," Roseberry added. "On a very basic level, this really underscores that children are social creatures who learn best from live interactions with other human beings.”

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