This post is part of our series on infant sleep and its effects on development, published in collaboration with the Journal of Infant Behavior and Development. The featured research appeared in a special issue on the impact of infant sleep on cognitive, social, and physical development, as well as how parents and healthcare providers can promote healthy sleep and development in infancy.
Key insights for caregivers about nap time
Babies need a lot of sleep, as it is essential for learning, and the early years are full of new experiences and information. Taking a nap shortly after learning something new can help toddlers remember new information better than if there is a delay between learning and sleeping. Parents can support healthy sleep and learning by recognizing signs of tiredness and providing regular opportunities for their infants to sleep.
Why do toddlers sleep so much?
On average, infants sleep 54 to 70% of their first year. Researchers believe that babies need a lot of sleep because they are confronted with so much new information every day in their early years, and sleep helps them process and remember the events of the day. For example, taking a nap helps infants remember facial features, solve new and challenging problems, and accurately imitate learned behaviors. By taking a nap soon after learning something new, babies strengthen their memory and understanding of the new information.
Naps can support learning by actively processing information in the brain during sleep. Alternatively, naps can also support learning by protecting new information from other experiences that could disrupt the learning process before it occurs. In order to better understand the role of naps in infant learning, we wanted to find out whether the timing of a nap has an impact on how well young children learn and remember new information.
Studying the impact of nap timing on infant learning
We conducted a study with our colleagues Melissa Horger of the University of Massachusetts, Amherst and Anat Scher of the University of Haifa. We examined 29 babies (aged 10 ½ to 18 ½ months) who had recently started walking and stopped crawling within the last 10 days. We followed the families‘ typical nap times during home visits. In an initial session, we taught these new walkers to crawl through a play tunnel to reach their caregivers on the other side. This was a challenging task that the babies had to learn. New walkers must pay particular attention to maintaining balance while trying to move their bodies. Crawling through a tunnel required toddlers to switch from walking to crawling to fit their bodies inside. The combination of balancing and developing a strategy for transitioning postures resembles multitasking for babies. All of these requirements made this specific motor task a real challenge for infants at this particular stage in their development. This provided us with the perfect opportunity to observe the learning process, as most infants can learn to solve the tunnel problem, and because full-body tasks make learning observable in a preverbal population. We placed the babies at the tunnel entrance and gave them a series of cues when they struggled to figure out what to do. We counted the number of attempts and how long it took for them to enter the tunnel. Parents should provide their babies regular opportunities to take a nap and recognize signs of tiredness, such as rubbing their eyes or yawning, as timely sleep is important for learning. After this lesson on solving the tunnel problem, we removed the tunnel and let the families go about their regular activities for the next six hours. Some of the infants took a nap shortly after the first tunnel session at their regular time (the First Nap group), and some took a nap approximately four hours later at their regular time (the Delay Nap group). Therefore, all babies were taught the tunnel problem and then had a six-hour period in which they also took a nap.
We then presented the tunnel problem again. The main difference between the two groups was the timing of the nap during the six-hour window: The First Nap group napped earlier, while the Delay Nap group napped later.
Taking a nap shortly after learning is best
The First Nap group was able to solve the tunnel task better the second time than the Delay Nap group. For example, babies who took a nap right after learning required fewer cues and entered the tunnel faster during the test. In other words, by taking a nap sooner rather than later after learning something new, babies strengthened their memory and understanding of the new information and were able to integrate the new knowledge more efficiently.
How can parents support healthy sleep habits for their infants?
Parents and researchers have long known how important naps are for infants‘ learning and emotional regulation. Our study has shown that the timing of nap time is also important. The results suggest that parents should provide their babies with regular opportunities to take a nap and recognize signs of tiredness, such as rubbing their eyes or yawning, as timely sleep is important for learning. Our study has implications for early intervention work. Pediatric physical therapists, occupational therapists, and speech therapists typically try to teach specific skills to children. In these instances, parents may want to schedule sessions with these providers so that their infants and toddlers can take a nap soon after the appointment. If babies take a nap after such learning experiences, the new information may be solidified more quickly and easily than if they did not take a nap shortly afterward.