Sleep not only protects memories from being forgotten, it also makes them easier to access, according to a study published Monday by the University of Exeter.
The findings suggest that after sleep we are more likely to recall facts which we could not remember while still awake.
During the research period, a team of researchers from University of Exeter and the Basque Centre for Cognition, Brain and Language asked volunteers to remember novel and made-up words they had been told either before a night's sleep or an equivalent period of wakefulness.
They were asked to recall words immediately after exposure, and then again after the period of sleep or wakefulness.
The results showed that volunteers performed better at recalling the words after sleep than when they remained awake.
Sleep almost doubles our chances of remembering previously unrecalled material, and 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," said Nicolas Dumay, who participated in the research.
He said 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.
