September 24, 2013
Preschoolers Who Take A Nap In Class Have Better Memory
April Flowers for redOrbit.com - Your Universe Online
Parents know that afternoon napping make children easier to deal with, but did you know that classroom naps support learning in preschool children by enhancing memory.A new study from sleep researchers at the University of Massachusetts Amherst, published in the Proceedings of the National Academy of Sciences (PNAS), is the first to show that children who took a midday siesta performed significantly better than children who did not take a nap before conducting an afternoon visual-spatial task. Those same napping children also performed better the next day.
The researchers, led by psychologist Rebecca Spencer, say that their results suggest naps are critical for memory consolidation and early learning.
"Essentially we are the first to report evidence that naps are important for preschool children," Spencer says. "Our study shows that naps help the kids better remember what they are learning in preschool."
The study is part of a five-year, $2 million grant from National Institutes of Health’s (NIH) Heart, Lung and Blood Institute (NHLBI) to significantly advance knowledge about how napping and sleep affect memory, behavior and emotions in preschoolers.
Previous studies have shown that attending preschool offers life-long benefits in physical health, emotional stability and quality of life. In the US, 70 percent of four- and five-year-old children attend preschool. The number of publicly-funded preschools is increasing, leading parents and administrators to question the usefulness of the naps.
"There is increased public funding for preschools and increased enrollments in preschools due to a surge of research showing the long-term health and educational benefits of early education. But there was no research on napping so they were a target for elimination in order to make more time for more learning. We offer scientific evidence that the midday naps for preschoolers support the academic goals of early education."
Spencer and her research team, including students Kasey Duclos and Laura Kurdziel, recruited 40 children from preschools across western Massachusetts. In the morning, the children were taught a visual-spatial task similar to the game "Memory," where the children see a grid of pictures and have to remember where different pictures are located. Each child participated in two conditions.
Children in the first condition were encouraged to nap during their regular classroom nap time, with naps lasting an average of 77 minutes as recorded by observers in the classroom. In the second condition, children were kept awake during the nap time. After the nap and wake conditions, the children's memory for the game was tested. Their memory was tested again the following day to see if nighttime sleep affected performance.
The researchers found that the children who had not taken a nap only had 65 percent accuracy in determining the locations in the memory test. Those who took naps had 75 percent accuracy in the same task.
"While the children performed about the same immediately after learning in both the nap and wake conditions, the children performed significantly better when they napped both in the afternoon and the next day," the authors summarize. "That means that when they miss a nap, the child cannot recover this benefit of sleep with their overnight sleep. It seems that there is an additional benefit of having the sleep occur in close proximity to the learning."
An additional 14 preschoolers were recruited to explore the effect of sleep stages and whether memories were actively processed during the nap. They were brought into a sleep lab where the researchers conducted polysomnography -- a record of biophysiological changes that occur during the preschoolers' average 73-minute naps.
The researchers noted a correlation between sleep spindle density, which is activity associated with integrating new information, and the memory benefit of sleep during the nap.
"Until now, there was nothing to support teachers who feel that naps can really help young children. There had been no concrete science behind that," the neuroscientist says. "We hope these results will be by policy makers and center directors to make educated decisions regarding the nap opportunities in the classrooms. Children should not only be given the opportunity, they should be encouraged to sleep by creating an environment which supports sleep."
The research team suggests that preschools develop napping guidelines. They say there is a need for further research on how to protect and promote naptime for young children to enhance their learning. Over the next five years, Spencer and her team will study about 480 preschoolers between 3 and 5 years old, including both boys and girls in diverse communities across western Massachusetts. The research will be widely-based, ranging from fact-based and emotional memory studies with and without napping. The researchers will look at measures of physical activity levels and parent reports of their children’s nighttime sleep, to find out how classroom experience interacts with sleep and physical activity and whether daytime sleep enhances learning. The relationship between sleep and behavior disorders will also be explored.
“I think we’ll have a rich data set for examining sleep, physical activity and the child’s behavior,” says Spencer. “We think that the nap benefit is going to be especially useful for kids who don’t get optimal overnight sleep. Culture plays a role in how late you stay up, and some kids live in noisy inner city neighborhoods. If we can help them with a nap, we want to know that.”