Power naps 'boost memory'

A brief catnap can boost your memory, say German scientists. They suggest that it's the mere act of nodding off - when recent events are replayed in the mind - rather than the duration of the snooze that matters.

While studies have shown that a good night's sleep has a beneficial effect on memory, this latest research from the University of Dusseldorf - published in the Journal of Sleep Research - found that having a power nap for just five minutes during the day not only refreshes the brain, it also improves recall.

The researchers asked a group of students to memorise a list of words and then recall them after an hour playing solitaire. The volunteers who had a five-minute doze at the start of the test recalled significantly more words.

"It seems much more is happening during the initialisation of sleep than we thought," said lead researcher Dr Olaf Lahl. "Maybe much of sleep's functional aspects are accomplished at its very beginning."

Other experts are less convinced saying that for memory to be enhanced, a longer period of sleep is needed.

In separate research - presented at the American Stroke Association's conference - scientists reported that dozing during the day may be an early warning sign of stroke risk among the elderly.

The researchers found that stroke risk was two to four times greater in older people who unintentionally fell asleep during the day. They suggested that people with sleep problems should see their GP.

If you're having problems nodding off, read Tips to help you get a good night's sleep.

Watch the NewYou video Insomnia - how to sleep your way to a healthier day.