In 2013, University of Massachusetts researchers showed 40 preschoolers cartoon pictures and tested their memory before and after an afternoon nap - children who slept forgot less and remembered roughly 10% more than those kept awake

A daytime nap may do more than give preschoolers a break from their busy schedules. Researchers found that children who slept during their regular afternoon nap retained more of what they had learned earlier in the day than those who remained awake, suggesting that midday sleep plays an important role in memory consolidation during early childhood.

In 2013, Laura Kurdziel, Kasey Duclos and Rebecca M. C. Spencer of the University of Massachusetts Amherst set out to determine whether classroom naps actually help preschool children learn and remember new information. Their research, “Sleep spindles in midday naps enhance learning in preschool children,” was published in the journal Proceedings of the National Academy of Sciences (PNAS) on September 23, 2013.

The researchers studied 40 preschool children, with an average age of about 50 months, in their regular classroom settings. In the morning, the children were shown the locations of cartoon images arranged on a grid. After an initial memory test, they went through their normal classroom routine before the afternoon nap period.


During the nap opportunity, the children were tested under two conditions: in one, they were encouraged to sleep, while in the other, they were kept awake with quiet activities. The researchers then tested how well the children remembered the images' locations. The same memory test was also conducted the following morning for a subset of the children.

The difference was significant. Children remembered more spatial information after napping than after an equivalent period awake. According to the researchers, participants recalled 10% more spatial locations after a nap.

The advantage could not simply be explained by children being more alert after sleeping. In fact, experimenters rated children as sleepier after the nap than in the wake condition. More importantly, the memory advantage persisted the following morning, even after the children who had stayed awake had received a full night's sleep.

That finding suggested that the nap was doing something more than temporarily improving attention: it appeared to help consolidate newly learned memories.