SUNDAY, Feb. 21, 2010 (Health.com) — If you feel a little sluggish after lunch, a quick snooze can perk you up. According to a new study, it may even make you smarter.
The longer you’re awake, the more difficult it is for your brain to store new information, whether it’s faces and names, the details of a conversation, or mental notes for a big presentation. An afternoon nap seems to refresh this short-term memory and free up space for new information, researchers found.
In the study, the researchers asked 39 college students to learn a series of new names and faces at noon and match the faces and names a few minutes later. They then performed the same test at 6 p.m. the same day. A group of students who took a 90-minute afternoon nap at 2 p.m. performed better than non-napping students, who had a serious decline in their memory test scores.
Why? The part of your brain where short-term information and memories are stored is a bit like your email inbox, says the study’s lead author, Matthew P. Walker, the head of the Sleep and Neuroimaging Laboratory at the University of California, Berkeley. “You can only receive so many emails before your inbox starts to bounce,” he says. “When you sleep, essentially what you may be doing is clearing out that inbox to another folder, [so] you have a refreshed capacity to receive new emails.”
Walker and others have previously studied the harmful effects of sleep deprivation (such as all-nighters) on sleep and learning capacity. This study is among the first to demonstrate that the brain’s ability to absorb new information declines over the course of a normal day, and that naps can reverse this decline, according to Walker, who presented his findings on Sunday at the American Association of the Advancement of Science’s annual meeting in San Diego. The research was funded by the National Institutes of Health.
Don’t email this article to your boss to justify sleeping on the job quite yet. Neil Kline, DO, a board-certified sleep physician, says that while “the average reader will take away from this that taking a nap is a good thing and will improve memory,” Walker’s study has some caveats.
Next page: Naps may not be as effective for everyone