If you’ve ever pulled an all-nighter before a big exam or presentation, you’re probably familiar with that frustrating feeling of brain fog, of trying to remember a detail that’s just out of reach. It turns out you probably should’ve followed that age-old advice to sleep on it.
New research finds that studying just before sleeping improves a student’s ability to recall information. The researchers say they decided to study the impact of sleep on memory because although there have been numerous studies on the benefits of sleep, experts in the field still didn’t know whether going to sleep or staying awake for long periods of time caused people to forget information.
The researchers divided Harvard students who normally slept at least six hours a night into groups and asked them to memorize two sets of word pairs—one set related semantically, like ‘school’ and ‘blackboard’, and the other made up of random, unrelated words. One group learned the words at 9 a.m. then went about their day. The second group learned the words at 9 p.m., and then went to sleep immediately afterwards. While sleep didn’t have an impact on whether the participants could remember the related pairs of words, those who went to sleep just after learning unrelated word pairs were able to recall them more quickly and easily.
Even better, the researchers concluded that when you go to sleep after learning something, you slow down the rate of memory deterioration—the rate at which you forget things—after you wake up. This suggests that getting adequate sleep is a critical part of learning something new, and plays an important part in stabilizing new memories. There are sure to be follow-up studies, but sleeping instead of pulling an all-nighter seems a wise choice.