Sleep sharpens power to recall memories, study finds
Monday 27 July 2015 00.01 BST Last modified on Monday 27 July 2015 01.00 BST
Last-minute “swotting” for an exam before going to bed might be a good tactic for students, according to research on the benefits of “sleeping on it”.
Sleep almost doubles the chances of remembering previously forgotten information, scientists found. They believe it makes memories more accessible and sharpens our powers of recall.
Volunteers taking part in a study were asked to remember made-up words they had been told either before a night’s sleep or after 12 hours of wakefulness. The “sleepers” were much better at recalling the words than the participants who had remained awake.
Dr Nicolas Dumay, a psychologist from the University of Exeter, said: “Sleep almost doubles our chances of remembering previously unrecalled material. The post-sleep boost in memory accessibility may indicate that some memories are sharpened overnight. This supports the notion that, while asleep, we actively rehearse information flagged as important.
“More research is needed into the functional significance of this rehearsal and whether, for instance, it allows memories to be accessible in a wider range of contexts, hence making them more useful.”
Dumay believes the memory boost comes from the hippocampus, a part of the brain that plays a key role in recall. During sleep, recently encoded memory episodes are “unzipped” and replayed to the region of the brain originally involved in their capture.
The findings are reported in the journal Cortex.