Sleep Deprived Learning
A person is not able to retain information when they are sleep deprived. Rapid-eye-movement sleep (REM sleep) is essential for a good memory. In one research study, individuals engaged in an intensive language course were observed to have an increase in rapid-eye-movement sleep, or REM sleep. This is a stage of sleep in which dreaming occurs most frequently. Scientists hypothesized that REM sleep played an essential role in the acquisition of learned material (source). A student’s performance in school and the amount of sleep they receive are in direct correlation with each other. It has been proven that adolescents who receive a good amount of sleep receive better grades than those who receive less sleep. Researchers at the University of Minnesota reported the results of a study of more than 7,000 high-school students whose school district had switched in 1997 from a 7:15 am start time to an 8:40 am start time. Compared with students whose schools maintained earlier start times, students with later starts reported getting more sleep on school nights, being less sleepy during the day, getting slightly higher grades and experiencing fewer depressive feelings and behaviors (source).
This chart shows the correlation between the amount of hours students sleep per day and their grade point averages. Radwin reports that, on average, the GPA of students who usually sleep at least seven hours per weeknight is 0.10 points (a tenth of a letter grade) higher than students who sleep five to six hours. And it's 0.29 points higher (about the difference between a B+ and a B) than students who slept less than five hours (source). The study clearly shows that as the hours of sleep the students receive per day increases, their grade point averages also increase. Schools have tried all kinds of ways to improve their students’ grades. Delaying the start time of school by half an hour would show better results than anything the schools have tried in the past.