The journey of thriving as an expat often leads into unexpected territories. When I initially began this blog, the topic you’re about to read was beyond my imagination. However, as I delve deeper into the expat life through my posts, I’ve realized the profound impact that sleep has on every part of expat life, especially stress.
Now before you zone out or exit with a thought of “Yes, I know I need more sleep”, that is not what this article is about. I’d like to share intriguing research about this vital link between language learning and sleep. It’s so vital, that I can say with scientific backing you can’t learn a language without sleeping well.
So whether you’re a student, in a language learning “phase” of your expat life, or just trying to learn language while you go about a normal daily life, read on to learn how you can maximize your language learning…it’s as easy as sleeping.
“If you want to remember your learning so you can build on it every day, you need to sleep well.”
(Dr. Greg Wells, M.D., The Ripple Effect: Sleep Better, Eat Better, Move Better, Think Better, p. 42)
Today we’ll consider why your brain needs sleep to process new language content, how sleep is critical for remembering language content, why sleep is vital specifically for language learning, and conclude with some advice from medical experts on getting quality sleep.
Your brain can’t learn when tired
As counter-intuitive as the above claim is to the energy-drink-fueled all-nighter cram sessions common across schools, the research on this one is abundantly clear. Dr. Matthew Walker—a sleep researcher at UCLA Berkely—studied the brain activity of people who were trying to learn after being sleep deprived for just one night. He discovered that when he looked at the part of the brain that acquires new information, the hippocampus, his team “could not find any significant learning activity whatsoever. It was as though sleep deprivation had shut down their memory in-box, and any new incoming information was simply being bounced” (Matthew Walker, Ph.D. Why We Sleep: Unlocking the Power of Sleep and Dreams, 153, emphasis added).
The reason for this is that your brain processes memory during sleep. It’s during sleep that our brain moves short-term memories from their temporary spot in the hippocampus to long-term storage in the prefrontal cortex (or else discards the memory). This process empties the hippocampus so that it can learn more. But, as Dr. Wells summaries, “If we don’t sleep, our short-term memory seems to fill up, and we just don’t learn as well” (The Ripple Effect, 27). When a bucket of water gets filled up, it doesn’t matter how much more water you try to pour into the bucket or if you use a firehose to try to spray more in—the bucket won’t hold more water. How do you empty the bucket so you can learn more? Sleep.
What was the results of Dr. Walker’s experiment of people trying to learn when tired? He let the participants in the study sleep for two full nights so that they were well-rested when he tested them. Dr. Walker found:
“there was a 40 percent deficit in the ability of the sleep-deprived group to cram new facts into the brain (i.e., to make new memories), relative to the group that obtained a full night of sleep.”
Dr. Walker, Why We Sleep, 154, emphasis added
Depriving yourself of sleep can mean your learning is 40% less effective than if you’re fully rested. And, sure, this example was one night of total sleep deprivation, but Dr. Walker goes on to write, “You don’t even need the blunt force of a whole night of sleep deprivation. Simply disrupting the depth of an individual’s NREM [non-REM] sleep with infrequent sounds, preventing deep sleep and keeping the brain in shallow sleep, without waking the individual up will produce similar brain deficits and learning impairments” (Dr. Walker, Why We Sleep, 153). That’s right—you can get a full night’s sleep and have the same learning impairment if you just don’t get into deep sleep.
Want to set yourself up for success in your language acquisition? Get good, quality sleep or else the language you’re trying to learn won’t even enter your brain, much less be learned.
Your brain can’t form long-term memories when tired
Sleep is foundational to your brain’s ability to form both short and long-term memories, memories which are crucial for any learning, especially for language learning. Want to do a better job learning those vocabulary words? Ensure you have quality sleep.
As mentioned, short-term memory in the hippocampus “fills up” if you don’t get enough sleep. Further, ample amounts of sleep are necessary in order to form long-term memories. Consider these findings about sleep and memory:
“Those few memories you are able to learn while sleep-deprived are forgotten far more quickly in the hours and days thereafter. Memories formed without sleep are weaker memories, evaporating rapidly. Studies in rats have found that it is almost impossible to strengthen the synaptic connections between individual neurons that normally forge a new memory circuit in the animals that have been sleep-deprived.
Imprinting lasting memories into the architecture of the brain becomes nearly impossible. This is true whether the researchers sleep-deprived the rats for a full twenty-four hours, or just a little, for two or three hours. Even the most elemental units of the learning process—the production of proteins that form the building blocks of memories within these synapses—are stunted by the state of sleep loss.”
Dr. Walker, Why We Sleep, 154, emphasis added
Granted, humans aren’t rats—but his research indicates that even a two our three hour sleep deprivation substantially degrades the quality of memory formation. Dr. Walker cites research from his colleague, Dr. Stickgold at Harvard Medical School, who ran an experiment where individuals learned something, were deprived of sleep the next night, and then were allowed two full nights of sleep before they were tested on what they had learned. Despite having back-to-back nights of quality sleep, these individuals “showed absolutely no evidence of a memory consolidation improvement” (Why We Sleep, 155).
In other words, what matters is not how much you sleep in a week, but how much you sleep the first night after learning. Miss that night, and the opportunity for memory formation is gone, no matter how much sleep you may get the next night.
Want to learn a language? You can practice and study 8 hours a day, but it won’t help you much if you’re not getting quality sleep to turn that learning into long-term memory. As Dr. Walker puts it:
“Practice does not make perfect. It is practice, followed by a night of sleep, that leads to perfection.”
Dr. Walker, Why We Sleep, 126
Your brain improves memory when well-rested
In the research referenced earlier, Dr. Robert Stickgold not only considered what happened after one night of sleep deprivation, he compared what effect multiple nights of sleep had on memory formation. Students who were not deprived of sleep came back to his studio to demonstrate their learning after one, two, or three nights of sleep. Fascinatingly, “the more nights of sleep participants had before they were tested, the better their memory was” (Dr. Walker, Why We Sleep, 155). Sleep was crucial not only to the initial formation of memories, it strengthened the memories of what people had already learned.
One night of sleep loss can prevent memories from being formed; but multiple nights of quality sleep strengthens the memories that are formed. Want to learn a language? Want to remember the content you learned yesterday or last week? Sleep well the night after learning it—and keep sleeping well.
Sleep is crucial for language learning specifically
I get a front-row seat as my kids learn two languages (English and the local language) and it’s fascinating to watch them figure out grammar. They don’t have to be taught grammar and yet they end up getting their grammar perfect, whereas I work hard at it and still get it wrong. Linguists have performed fascinating experiments with kids and it’s incredible what even three or four year olds can do. I may or may not have just performed this same experiment on my 4-year-old.
Draw a picture of a monster and tell your child it eats mud. Your child can tell you that it is a mud-eater. Draw another picture that eats mice and they’ll call it a mice-eater. Draw another picture and tell your child it eats rats, and they won’t call it a rats-eater. They’ll call it a rat-eater. Why sometimes plural and sometimes singular?
Linguist Gabriel Wyner, who writes of this example is his fantastic book Fluent Forever explains:
“There’s a subtle grammar rule operating here, where nouns with irregular plurals (mouse–mice) form compound nouns using their plural forms (mice-infested), and nouns with regular plurals (rat–rats) form compounds using their singular forms (rat-infested). This is the sort of annoying, esoteric rule that gives my English students nightmares, and yet every illiterate English-speaking kid learns it perfectly” (197).
Linguists don’t agree about how kids, who know nothing about irregular plurals and compound nouns, get these things right. But what it abundantly clear is when the kids learn these things: during sleep, specifically Rapid Eye Movement (REM) sleep. That’s the phase of sleep that we associate with dreaming.
Dr. Walker, explains: “During the dreaming sleep state, your brain will cogitate vast swaths of acquired knowledge, and then extract overarching rules and commonalities—’the gist.’” (Why We Sleep, 219). In a footnote on this sentence, Dr. Walker gives this example:
“One example is language learning, and the extraction of new grammatical rules. Children exemplify this. They will start using the laws of grammar (e.g., conjunctions, tenses, pronouns, etc.) long before they understand what these things are. It is during sleep that their brains implicitly extract these rules, based on waking experience, despite the child lacking explicit awareness of the rules” (Why We Sleep, 234, emphasis added).
This is not unique to children, though they’re clearly more apt at the process than adults—interestingly, they also sleep far more than adults. Even in adults, REM sleep enables your brain to connect new bits of information with old information and understand their relationship. Sleep enables not just memory of what you’ve learned, but understanding in a holistic sense.
Even though Dr. Walker’s chapter is about creativity, not language learning, he regularly goes back to the language example to show how sleep enables the brain to understand entire systems of information:
“A delightful example is observed in infants abstracting complex grammatical rules in a language they must learn. Even eighteen-month-old babies have been shown to deduce high-level grammatical structure from novel languages they hear, but only after they have slept following the initial exposure.
As you will recall, REM sleep is especially dominant during this early-life window, and it is that REM sleep that plays a critical role in the development of language, we believe. But that benefit extends beyond infancy—very similar results have been reported in adults who are required to learn new language and grammar structures.”
Dr. Walker, Why We Sleep, 227–228, emphasis added
Having trouble deciphering grammar? Is it not coming intuitively to you? Then you need sleep—and, specifically, REM sleep.
Conclusion
In essence, sleep stands as an absolute cornerstone for effective language learning. It is not just a tool to gain information but a vital mechanism enabling your brain to process, retain, and comprehend the intricacies of a new language. Without adequate sleep, the path to mastering a language becomes significantly more challenging. Therefore, if language acquisition truly matters to you, prioritize ample and high-quality sleep as an integral part of your learning strategy.
Sleep. You can’t learn a language without it.
Check out “part 2” of this series: 12 expert-proven tips to improve your sleep.
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