It probably goes without saying that sleep is extremely vital to our health and well-being. Koalas get it — they sleep 18 to 22 hours per day. That would be a bit overboard for humans, but the point is, the importance of a good night’s sleep cannot be overemphasized. While its benefits are numerous, we’re most interested in the connection between sleep and learning, a relationship that scientists are continuing to explore.
Research shows that sleep can help you learn new things and is particularly useful when you’re learning a new language — but maybe not in the ways you think.
Sleep And Learning: What The Science Says
Research shows that while you’re asleep, your brain is hard at work — processing information you took in during the day. Many people are familiar with the REM (rapid eye movement) phase of sleep, which is when most dreaming occurs, but a lesser-known phase of non-REM sleep is called slow-wave sleep, or SWS. Researchers have found SWS to be an important phase for memory processing.
Dr. Jakke Tamminen, a psychology lecturer and researcher at Royal Holloway University of London, studies how sleep affects learning and the role memory consolidation plays in that process.
One of Tamminen’s studies involved a control group of participants learning new vocabulary words and then being tested on them later the same day, and an experimental group, who were tested after sleeping.
But these weren’t just random vocab words. They were words from a fictional language with a hidden rule binding them together. The study found that participants in the experimental group were able to understand and apply the rule while sleeping and were better able to recall the words they learned than those who did not sleep.
Memory consolidation is linked to what are called sleep spindles, or short bursts of brain activity that occur during the SWS phase of sleep and are involved in the reactivation of new information. The study found that participants who exhibited the highest number of sleep spindles showed the most signs of integration between existing memories and new ones, which helped them retain the new vocabulary.
“Teachers have long suspected that proper rest is critical for successful learning. Our research provides some experimental support for this notion,” said Dr. Kathy Rastle, head of Royal Holloway’s psychology department.
Debunking The Myths About Learning In Your Sleep
Sleep clearly plays an important part in learning anything, and particularly learning languages. But sometimes this connection is taken beyond reality.
As appealing as it sounds to be able to play a French recording while you sleep and wake up fluent, that’s unfortunately not how the brain works. The idea of hypnopaedia — learning new information in your sleep — has been largely debunked, despite its popularity, which may have been boosted by its use in Aldous Huxley’s Brave New World.
In the 1950s, two researchers conducted a study, in which they played a recording of someone listing trivia facts for participants while they slept. When the participants awoke, they didn’t seem to have retained any of the facts listed.
From the science, we can pretty safely conclude that you can’t learn entirely new material while you sleep, but you’re more likely to learn new material because you slept.
So you’re welcome to put on this 8-hour YouTube video of Spanish phrases tonight when you’re asleep, but don’t be disappointed when you get nothing out of it.