STUDENTS CRAMMING for the Leaving take note – having a short nap now and again will make you smarter. Grabbing a quick snooze helps the brain to clear its memory “inbox”, leaving more room for more facts and figures, according to a psychology professor at the University of California, Berkeley.
Conversely, pulling an all-nighter is definitely the wrong way to go, said Prof Matthew Walker who discussed the advantages of short naps yesterday during a session at the American Association for the Advancement of Science’s annual meeting in San Diego.
Staying up all night decreases the brain’s ability to hold on to new facts by almost 40 per cent, but getting a normal night’s sleep – allied with a nice lunchtime nap – not only recharges the mental batteries but can actually make you smarter, Prof Walker added. “Sleep not only rights the wrong of prolonged wakefulness, but, at a neurocognitive level, it moves you beyond where you were before you took a nap.”
He gauged the benefits of napping after lunch using 39 subjects split into two groups – one that took a 90-minute nap immediately after lunch and one that had no nap.
First they completed an intensive learning task that focused on the part of the brain responsible for memory, the hippocampus. Then they were able to drift off for a 90-minute siesta.
Later in the afternoon they again did tough learning exercises, and those who did not get to have a sleep became worse at learning. Those who did have the nap, however, not only did better, they improved on their previous capacity to learn.
The brain typically uses the hippocampus for short-term memory that is later shunted into the long-term memory store in the brain, Prof Walker said. “It is as though the e-mail inbox of your hippocampus is full and until you sleep to clear out those fact e-mails, you are not going to receive any more mail.” This memory swapping occurred during a sleep phase when you are not dreaming. Significantly, we spend at least half our sleeping hours in this particular non-dreaming form of sleep.
“I can’t imagine Mother Nature would have us spend 50 per cent of the night going from one sleep stage to another for no reason. Sleep is sophisticated. It acts locally to give us what we need,” he said.