More than a third of adults struggle with getting enough sleep—and recent research suggests it has serious implications for their ability to learn and focus.
SEPTEMBER 27, 2023
If you feel like you're not catching enough ZZZ's, you're not alone. At least a third of adults aren't getting the recommended amounts of sleep they need—and women suffer more sleep issues than men.
This matters because not only has insufficient sleep been linked to heart disease, obesity, type 2 diabetes, and depression, it’s also associated with learning deficiencies. A recent study published in Proceedings of the National Academy of Sciences (PNAS) shows that college students who don’t get enough sleep have lower grade point averages and diminished school performance—and experts say one’s ability to concentrate at work can be similarly affected.
There are many ways in which sleep helps us each night as numerous bodily processes and systems slow down, rest, and recover from the day’s activity. Heart rate and muscles relax, healing occurs, and body temperature decreases. But one system that kicks into overdrive during sleep is the area of the brain associated with learning and recollection.
“When we sleep, our brain goes through the information we learned during the day and stores what’s necessary,” explains Rajkumar Dasgupta, a sleep medicine and pulmonary specialist at the Keck School of Medicine of the University of Southern California. “When we’re well rested, we’re also better able to stay on task and avoid getting sidetracked.”
Indeed, adequate sleep— seven-nine hours per night for adults, eight-10 for teens, according to the U.S. Centers for Disease Control and Prevention—is associated with improved test scores, increased ability to problem solve, enhanced quality of learning, improved behavior performance, increased potential for inspiration and fresh ideas, and better absorption of information. What’s more, 2022 research published by the Nature Portfolio journal Humanities and Social Sciences Communications, shows that sleep deprivation reduces cognitive function, which can make it more difficult to concentrate, focus, and perform.
Sleep discrepancies by gender
Though the learning disadvantages that stem from lack of sufficient sleep are believed to affect men and women similarly, women may be especially impacted by sleep deprivation.
Studies show that women are more prone to sleep disorders, including unpleasant dreams, sleep disturbances, and insomnia. The cause of this sleep discrepancy is usually related to hormones connected to menstruation since the sex hormone progesterone—which helps with sleep regulation—is often low during ovulation.
Rebecca Spencer, a professor of psychological and brain sciences at the University of Massachusetts, Amherst, says that "pre-menopause and menopause are also killers to sleep." Dasgupta notes that women are also "more likely to take care of children and other family members, which can make it difficult to get enough sleep."
Because of such factors, women need to be particularly mindful of the quantity and quality of their sleep. "Women don't need more sleep as a whole, but those women that have poor sleep would maintain better memories and comprehension if they had better sleep," says Spencer.
Why sleep is the real memory maker
While improved learning and comprehension are ideal no matter one’s gender, neither does much good unless one can also retain and recall what’s been taught. That’s where sufficient sleep becomes especially important. “Sleep plays a very active role in memory consolidation,” says Spencer. She explains that memory consolidation is the brain’s process of sorting, replaying, and storing all that’s been learned and experienced each day to be accessed later. “While memory consolidation can happen while awake, this process is stronger or greatest during sleep,” she says.
The hippocampus, located within the inner region of the temporal lobe of the brain, close to the base of one’s skull, plays a significant role in this undertaking. Spencer calls the hippocampus, “a short-term storage site” for the things we learn. She says that’s where information gets piled up throughout one’s day like papers on a work desk. “When you sleep, those ‘papers’ are filed away into a long-term filing cabinet to be retrieved as needed.” This long-term storage site is the cerebral cortex—the large, outer layer at the top of one’s cerebrum.
Spencer says this transferring process can take up much of the night, and that if we don’t get enough sleep, we may wake the next morning with some lessons or memories not yet transferred—causing them to become fuzzy when trying to recall them later.
Getting sufficient sleep also helps the brain experience the benefits of each sleep stage—a critical element of embedding memories, per PNAS research published last year. "Sleep helps us better cement what we have learned into long-term memory," explains David Creswell, a professor of psychology at Carnegie Mellon University.
Sleep also facilitates forgetting, "which is actually just as important for proper memory function as remembering is," says Andrew Budson, a professor of neurology at Boston University and coauthor of Why We Forget and How to Remember Better: The Science Behind Memory. He explains that while we sleep, our memories get edited to forget the unimportant details of the day to instead remember what matters, "so our brains are not cluttered with extraneous information."
Alertness equals understanding
Along with helping improve comprehension and memory retention, sufficient sleep also keeps at bay adenosine—a chemical that make us feel sleepy. Adenosine production is triggered by the neuromodulator melatonin as part of the body’s system for promoting and regulating sleep. "The longer we're awake, the more adenosine we accumulate and the more tired we feel," says Spencer. In such a drowsy state, we usually experience diminished clarity and impaired understanding.
"Sleep clears this adenosine load, thereby making us more focused, more attentive, and better able to concentrate and perform most cognitive tasks," says Spencer. And though recent research shows it's possible to put off this sleep pressure brought on by adenosine through stimulants such as caffeine, using such substances only mask the body's attempt to promote sleep and does nothing to replace the missed benefits of delayed slumber.
Budson says any such attempts only leave us feeling more exhausted the next day. "When we are tired, our attention is impaired, and attention is critical to remember what we are learning," he says.
How to improve sleep and learning
To improve one’s quality of sleep, the experts stress the importance of sticking to a regular sleep schedule, maintaining a dark and uninterrupted sleep environment, and avoiding large meals, alcohol, and caffeine before bed. "Another big common mistake is to use screens before bed," says Spencer. She advises avoiding screen exposure for at least 45 minutes before sleep to limit blue light stimulation and circadian rhythm disruption.
Such advice applies even to students behind on schoolwork. "I think it's pretty common for college students to assume that their best strategy for good grades is to stay up late studying and cramming for exams," says Cresswell. However, because sacrificing one's sleep is associated with so many reductions to school performance, "this late-night cramming strategy really backfires if your goal is good grades," he cautions.
Instead, Dasgupta recommends planning ahead and getting extra sleep the night before exams or study sessions. "Getting enough sleep is one of the most important things you can do to improve your learning and memory."
(Sources: National Geographic)
Đăng nhận xét