I recently returned from an overseas trip to the United Kingdom and, while recovering from the obligatory ‘jet-lag’, found myself wondering how the lack of sleep affects us and, in particular, our ability to learn.
It has long been known that sleep is essential to the healthy development of adolescents and young adults, as well as their success at school and in the workplace. But there is an increasing body of evidence that suggests that students are not getting enough sleep, and that this is negatively affecting their ability to learn at school.
Most sleep experts agree that adolescents need 9 hours of sleep each night to be engaged and productive students; less than 7 hours is considered to be insufficient sleep. Researchers from San Diego State University (2017) found that about 40 percent of adolescents in 2015 slept less than 7 hours a night, which is 58 percent more than in 1991 and 17 percent more than in 2009. They further learned that the more time young people reported spending online, the less sleep they got. Teens who spent 5 hours a day online were 50 percent more likely to get insufficient sleep compared to those who only spent 1 hour online each day.
Evidence that sleep aids learning
In order to examine the effect of sleep on classroom learning, Scullin and colleagues (2011) gave undergraduate students with no previous exposure to economics a lecture on supply and demand. Students were randomly assigned to one of two groups.
The first group watched the lecture in the morning and came back in the evening to take a test. The second group watched the lecture in the evening and came back in the morning to take a test. In this way, the time from lecture to test was held constant, but only the second group slept in between the lecture and test.
The test was divided into two parts. Half of the questions were very similar to the types of supply and demand questions that were used as examples during the lecture. The other half of the questions were called “integration” questions that required students to incorporate both supply and demand information to solve novel complex problems.
The results showed that students in the sleep group performed about 8% better on the problems that were similar to those from the lecture. But on the novel problems, students who had slept before taking the test performed 32% higher than those who had not slept! In other words, students retained more information after sleeping, but their ability to understand and apply that information received the biggest benefit with sleep. (See table image below)
Why does sleep aid learning?
One of the common misconceptions about sleep is that it is simply a restful time when nothing is happening or, in other words, that the brain is quiet. Quite to the contrary, the sleeping brain is very active, sometimes more so than during waking hours. The brain cycles through several different types of sleep throughout the night, sometimes with very fast activity and sometimes with what is called slow wave sleep. It is during slow wave sleep that the brain appears to replay the information that was learned while awake, which leads to consolidation of memories – moving them into long-term storage. Because the brain cycles through the different stages of sleep throughout the night, losing sleep means losing time for consolidation.
So, the bottom line...
Sleep is the easiest way for students to study. Getting a good night’s sleep will help considerably with retaining information in class, understanding that information, and learning new information. In other words, students are much more likely to do well on ANY kind of test if they get a good night’s sleep every night (not just the night before the exam, although that night is important too).
San Diego State University. "More teens than ever aren't getting enough sleep: A new study finds young people are likely sacrificing sleep to spend more time on their phones and tablets." ScienceDaily. ScienceDaily, 19 October 2017. <www.sciencedaily.com/releases/2017/10/171019100416.htm>.
Scullin, M., McDaniel, M., Howard, D., & Kudelka, C. (2011, June). Sleep and testing promote conceptual learning of classroom materials. Presented at the 25th Anniversary Meeting of the Associated Professional Sleep Societies LLC, Minneapolis, MN.
Image: Training vs Integration
Edward Wright | Head of Learning and Innovation