Evidence that sleep aids learning

In order to examine the effect of sleep on classroom learning, Scullin and colleagues (2) 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 gotten sleep 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.