Your mind is always at work, even when your eyes are closed.
Previous research has found sleep helps you store memories. But not only are you cataloguing old information, you may also be learning new information while you get some shuteye, according to a new small study.
Research published in the journal Nature Communications found that the brain is able to form fresh memories during sleep. Researchers played complex sound patterns while participants were logging Zs and discovered the snoozers were able to recognize the noises again when they were awake.
To reach the results, the study authors hooked up 20 participants to machines that measured the brain’s electrical activity. This was so the study authors could monitor each volunteer’s phase of sleep (rapid eye movement, or REM, for example) throughout the night. Researchers played white noise for the study volunteers before they fell asleep, which was interspersed with pings and other sounds. They asked the volunteers to indicate when they heard distinct patterns in the noises.
After they drifted off, the researchers continued to play the same sound patterns every so often, as well as observed when the participants were in each phase of sleep.
The next morning, the researchers played white noise and the sound patterns for the participants one last time. That’s when the study authors observed something interesting: Each of the participants were better at identifying patterns that were played for them during REM sleep. What’s more, the sleepers didn’t remember the patterns that were played for them during their lighter phases of sleep at all.
The results not only suggest learning can happen when you sleep, but in certain stages, the opposite effect can also occur. The study found that “memory traces can be both formed or suppressed during sleep, depending on sleep phase,” the authors wrote.
There are a few caveats: The study sample size was small, so it can’t necessarily be definitively applied to a larger population. Additionally, the data was observational. The study authors note they can’t explain why this happened, just that it occurred. During the study, the participants couldn’t indicate how or what happened that made them remember the sound patterns better, either. They just knew that they remembered them.
The authors theorize that this process could just be the brain’s way of sorting through memories and information and prioritizing it, Quartz reported. However, more research needs to be done to explore the full effects of the phenomenon and to figure out if humans’ memory during sleep can extend to other things, like new vocabulary, a new language or even mathematical equations.
That being said, it’s not like this is the first time a connection has been found between brain activity and sleep: Previous research published in 2012 found that humans could learn different patterns of smells during sleep. Getting those Zs also helps aid in decision making, boosts your mental health and increases focus.
So, while it doesn’t seem like you can learn Spanish or calculus in your sleep anytime soon, the brain-boosting benefits of shuteye are certainly apparent. If anything, you can use the new research as an excuse to get in a few winks at work ― you know, for your noggin and memory recall.
CORRECTION: A previous version of this article incorrectly identified REM sleep as the deepest stage of sleep.