A power nap indeed works to recharge the brain, improving memory, according to findings of a study on sleep and midday napping by researchers from the University of California at Berkeley. Led by study author Matthew Walker, the team of scientists compared the results of memory tests after a group of test subjects took a 100-minute nap versus those who did not.
The findings were announced at the annual meeting of the American Association of the Advancement of Science (AAAS) in San Diego.
The results, though preliminary, showed the group that powered down for a spell during the afternoon did better on the memory test, which was designed to stimulate the hippocampus, a part of the brain thought to be linked to memory function. Walker compared napping to clearing your e-mail inbox or rebooting a computer.
"It's as though the email inbox in your hippocampus is full and, until you sleep and clear out those fact emails, you're not going to receive any more mail," he said in a report by British newspaper The Guardian. "It's just going to bounce until you sleep and move it into another folder."
The study found of the 39 students who participated, the group of 20 that took the nap performed better on the memory test. The exercise consisted of matching pictures of faces to names. Walker said those students without a break fared about 10 percent worse than students who had taken the 100-minute nap. "This is further evidence that sleep plays a critical role in the processing of memories. It provides more evidence that it's not just important to sleep after learning, but you need it before learning to prepare the brain for laying down information," he said.
Walker also suggested humans are not biologically constructed to use their brains all day long and require a break so the brain can improve absorption of information. "We've all had that experience of being in meetings after lunch with people who are clearly drifting off," medical news site Health.com reported him as saying. "It's not their fault. It's their biology."
Also at the AAAS conference, The National Sleep Foundation reported that Americans get an average of 6.5 hours of sleep on weeknights, though 8 hours are recommended. Both men and women have decreased sleep; 67 percent of women report having poor sleep at least three nights a week. New studies show that two hallmarks of older adulthood-decreased sleep and cognitive decline-may be related. Moreover, sleep interventions can help reduce the decline in this age group, the foundation said.