Take that power nap - you could end up smarter



It may not make you popular with your boss but a snooze in the middle of the day dramatically boosts your brain power.

Medical researchers have shown that the power naps favoured by Winston Churchill, Albert Einstein and Margaret Thatcher not only refresh the mind, they also make people smarter.

They found snoozing for just one hour in the day is enough to increase the brain's ability to learn new facts in the hours that follow.

Medical researchers have shown that power naps not only refresh the mind, they also make people smarter

Dr Matthew Walker, a psychologist at the University of California, who led the study, said: 'Sleep not only rights the wrong of prolonged wakefulness but, at a neuro-cognitive level, it moves you beyond where you were before you took a nap.'

While many people will ridicule the idea of taking 40 winks at lunchtime, some of the most influential people on the planet were keen cat nappers.



Lady Thatcher claimed she got by on just four hours of sleep each night but had a short sleep in the day, while Bill Clinton famously took a 30-minute nap after lunch.

Famous daytime dozers also include John F Kennedy, Ronald Reagan and Florence Nightingale.

Many sleep researchers argue that the British habit of trying to stay awake from morning until night is inherently unhealthy.

They point to countries such as Spain where most people traditionally go for a post-lunch siesta.

In the Californian study, the researchers split 39 healthy students into two groups and asked them to carry out a learning task - linking faces with names - intended to tax the hippocampus, the region of the brain that helps store facts.

At 2pm, half the group took a 90 minute siesta, while the rest stayed awake.

At 6pm, the students were asked to carry out a new round of learning exercises.

Those who had a siesta performed

much better than those who remained awake throughout the day.

Overall, the nappers improved their capacity to learn in the evening session, the researchers told a meeting of the American Association for the Advancement of Science, in San Diego, California.

The researchers say sleep is needed to clear the brain's short term memory and make room for new information.

'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,' said Dr Walker.

'It's just going to bounce until you sleep and move it into another folder.'

Using ECG tests of the brain's electrical activity the scientists found that this memory-refreshing process takes place in a period between deep sleep and the dreaming state known as REM, or rapid eye movement.

The average person spends half their sleeping hours in this transitional sleep period, which is known as Stage 2 non-REM 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,' Dr Walker added.

'Sleep is sophisticated. It acts locally to give us what we need.'

The same study also found that students who have all-night revision sessions in the run up to exams, reduce the brain's ability to cram in new facts by a staggering 40 per cent.



