Naps can refresh brain power

Leonardo da Vinci took them, as did Napoleon Bonaparte, Johannes Brahms and Winston Churchill. And if you snooze long enough, researchers have now found, they also permit your memory banks to do their filing, leaving your brain cleared and ready to learn in the latter half of the day. UC Berkeley psychology professor Matthew Walker and colleagues put 39 young adults through a demanding learning task and tested on it at noon. At 2 p.m., they divided the students into two groups and invited half of them to take a siesta for 90 minutes while asking the remainder to stay awake. The siesta group went into the 6 p.m. task readier to learn and performed 10% better on the test than they had earlier.