Scientists from McGill University in Canada and the University of Bern in Switzerland found that REM sleep, the phase where your eyelids twitch and when you dream, is critical for preserving memories, the BBC reported of the data reported in the journal Science.
The sleep study, which was recently published in the journal Science, used sleeping mice to try and better understand the role REM sleep plays in remembering things. They used something called an optogenetic technique to control the brain cells in the mice by shining lights on them. This means they could disrupt their sleep without actually waking them up.
When the lights were shined on their brains their theta oscillation rhythm was disrupted and reduced. After this process, they found that the mouse in REM sleep was unable to remember what it had learned the day before and which object it had been investigating.
It’s largely been believed that REM sleep plays a really important role in the creation and consolidation of new memories, but this new research provides some of the clearest evidence to date. Dr Sylvain Williams, who has been working on the study from McGill University in Canada, said:
“Disrupting the activity only during REM sleep, and not other sleep, basically obliterates consolidation and memory formation […] It’s an eye-opener to say that REM sleep has this very central role.”