A good night's sleep undoubtedly makes learning easier. But what about a good afternoon nap? New ground is being broken in research on the benefits to learning for infants, toddlers and preschoolers during those daily siestas.

Napping for Adults

Sleep research on adults has revealed that the process of reviewing, sorting and storing the experiences of our waking life can be achieved in as little as a 20-minute cat nap, as well as serving as an important function of overnight slumbers. Confusing or conflicting information must work itself into your brain among the understandings you already possess. By the end of a dream or two, newly consolidated ideas have been tucked away into networks of your brain cells for long-term storage. The result is that you wake up understanding more than you did before you went to sleep.

But what about very young children who are learning so much every day? It appears that just getting a good night's sleep is not good enough.

Research on Napping

Rebecca Spencer, associate professor of psychology and neuroscience at the University of Massachusetts Amherst, was curious whether napping could be important to learning for preschoolers. As the mother of a 3-year-old and a 5-year-old, she was aware that many early childhood programs have been ramping up the academics, and as a result the traditional two-hour post-lunch nap time was sometimes shortened or cut out altogether. Her experiment, with partial funding support from NIH's National Heart, Lung and Blood Institute (NHLBI), was published in the "Proceedings of the National Academy of Sciences" in the fall of 2013. She reported that naptime for preschoolers is critical to allow children to make the most of their learning. Why? Because naps allow the brain to review, sort and store anything that was learned in the previous few hours.

The Study

Dr. Spencer and her colleagues used a visual memory game with 40 children, whose ages were almost 3 to less than 6-years-of-age, to see if having a nap afterward helped the children to remember more of the locations of a group of picture cards on a grid. After learning the game and getting an initial score, the children were induced to take a short nap (average 77 minutes) during the school's regular naptime. In a second trial, the same 40 children were kept awake during this same time period.

The Results

The results found that when they napped, children recalled an average of 75 percent of the picture cards, and when they did not nap they averaged just 65 percent. Age was not a factor. However, the children who were regular nappers - at least 5 days a week - did much worse without the nap. For each trial, the researchers re-tested the children the next day, after a full night's sleep, and still saw that those who were regular nappers, and had a nap after learning the game, had the highest scores. This suggests that the learning occurred during the nap and could not be made up during nighttime sleep. Dr. Spencer further observed, "It seems that there is an additional benefit of having the sleep occur in close proximity to the learning."

The explanation was that during the nap, the thought process needed to succeed at the game is repeated during dreaming, creating a long-term memory of it. A follow-up was done with 14 children going to a sleep lab for polysomnography - a record of biophysiological changes in the brain - during their naps. Stronger "sleep spindle density" - distinct bursts of brain activity on the electroencephalography (EEG) - correlated with greater post-nap scores on the memory game. These polysomnography results have been associated in prior research with learning during sleep for adults. Dr. Spencer explains what is happening, "Your brain creates a 'neural movie' of scenes from your day." A new neural pathway is lain among a particular network of brain cells, getting thicker with each repetition. She says, "Each replay makes the memory more efficient, stronger and stable."

Napping to Learn

Younger children typically nap twice a day. Another recent study from the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, found benefits to naturally occurring naps following a learning activity. The researchers observed that babies 9- to 16-months-old could remember made-up names of objects better if they had a one - two hour nap soon afterward. And that after the nap, similar-looking objects, same color but slightly altered shape, could be categorized together. "The infants who slept after the training session assigned new objects to the names of similar-looking objects," reported Manuela Friedrich of the Max Planck Institute. "They were not able to do that before their nap, nor were the ones who stayed awake able to do it. This means that the categories must have been formed during sleep." The researchers recorded the infants' brain activity while napping using EEG and saw the same dense sleep spindles associated with learning.

Benefits of Napping for Infants

What about the frequent naps of younger babies? Researchers at the University of Sheffield, England, and Ruhr University in Bochum, Germany, tested the ability of 216 healthy 6- to 12-month-old infants on their ability to recall newly learned skills. In January of 2015, Dr. Jane Herbert reported in the Proceedings of the National Academy of Sciences, "Until now people have presumed that the best time for infants to learn is when they are wide-awake, rather than when they are starting to feel tired, but our results show that activities occurring just before infants have a nap can be particularly valuable and well-remembered." In this experiment, babies were shown how to remove a mitten from a hand puppet and play with it. They were given a chance to copy these actions after delays of four and twenty-four hours. Age-matched infants were compared between those who did not nap after learning and those who napped for at least 30 minutes within four hours of learning how to take off the mitten. Overwhelmingly, those who napped remembered what to do while those who had not napped did not. A day later, the nappers still could recall better about what to do with the puppet than those who did not nap after learning.

The takeaway from all this research is to stand up for naps and let the children sleep and learn.

Deborah Wood, Ph.D. is a child development specialist residing in Annapolis, Maryland. She can be reached at 301-681-2728 or debbie@theccm.org for speaking engagements and consultation.