For generations, students desperate to pass their exams have resorted to staying up all night cramming.
It seems, however, that they would be better off taking the easy route – listening to taped revision notes in their sleep.
Scientists found napping for just an hour and a half while being played learning material boosted memory test scores. Those revising while awake remembered less – and lost out on extra rest.
Researchers gave 46 participants a set of 100 pairs of words and pictures, such as ‘America’ and an image of a banana. At first, they could remember no more than 50 percent of the combinations.
But a group allowed to nap for 90 minutes while listening to taped notes did much better.
The day after the experiment, they could remember 94 percent of words. This compared to just under 83 percent for those played the pairs while awake.
Around half of the advantage came from the benefits to memory of extra sleep, the results show, while the other half came from the recordings. Those who scored 94 percent scored less – 88 percent – on words they were not played.
Scans showed extra bursts of activity in the brains of those who heard the combinations while they were asleep.
Dr Scott Cairney, from the University of York, who led the study, said: ‘When you are awake you learn new things, but when you are asleep you refine them, making it easier to retrieve them and apply them correctly when you need them the most.’
But the authors warned that their study, published in the journal Current Biology, was conducted in laboratory conditions – and could not be guaranteed to work in the real world.
– Daily Mail