Language
Country/Area
No result found
Why does sleep have such a surprising effect on memory?
The value of sleep is gaining more and more attention in the scientific community, especially in the areas of learning and memory. Studies have shown that sleep is not only a process for resting the brain, but also plays an important role in the consolidation of long-term memory. Different sleep stages have different functions, with REM (rapid eye movement) sleep and slow-wave (non-REM) sleep playing their own unique roles in memory consolidation. REM sleep is primarily associated with the consolidation of implicit (non-declarative) memories, while slow-wave sleep is directly related to the consolidation of explicit (declarable) memories.
"Healthy sleep can significantly improve learning-related performance."
This distinction helps us understand that REM sleep helps us unconsciously learn skills, such as riding a bike, while slow-wave sleep supports our conscious memorization of facts that require active recall, such as historical dates.
As time goes by, more and more evidence emerges that a good night's sleep not only improves memory, but can fundamentally change the way we learn. From simple daily skills to complex cognitive tasks, sleep provides critical support. Some recent studies have shown that good quality sleep can help the brain filter out unimportant information and extract important patterns, a process described as "extraction of the essence."
The "synaptic modulation" hypothesis proposes that sleep also plays an important role in regulating learning that occurs during wakefulness, by increasing the efficiency and effectiveness of how the brain stores information, thereby optimizing the use of space and energy. Healthy sleep must include an appropriate ratio of NREM and REM stages, which each have their own role in the process of memory consolidation and optimization. During a normal sleep cycle, people alternate between NREM and REM sleep, with each cycle lasting about 90 minutes, including 20 to 30 minutes of REM sleep.
“Sleep allows the brain to be inactive, but it can review the brain activity patterns during learning at a faster speed.”
In addition, many studies have shown that a period of sleep can significantly improve the performance of motor skills. In a particular experiment, subjects were tested for sleep after learning a key-typing task. The results showed that the subjects' performance improved significantly during the sleep interval, while the performance improvement was very limited after just 12 hours of rest in the awake state.
Not only that, explicit memories also benefit from sleep, although the benefits are not as obvious as those of implicit memories. One study that looked at participants learning word pairs showed that paired sleep not only prevented memory decay, but also helped to solidify those memories. The importance of sleep was further highlighted by participants' performance when it came to the distraction trials.
"During sleep, unsuccessful neural connections are weakened, thereby strengthening other more important connections."
This also explains why studies show that napping can improve learning ability. The experimental results showed that the subjects who experienced REM sleep performed significantly better on the task than those who only experienced NREM sleep. A more recent study also highlighted that procedural tasks are better retained when learned before sleep, while declarative learning is more effective when performed in the afternoon.
In addition to memory, students' academic performance has also been directly linked to sleep quality. A quarter of high school students in the United States admit to having dozed off in class at least once, and students who don't get enough sleep typically perform poorly. In recent years, with the rise of distance learning, sleep quality surveys have received increasing attention, especially during the COVID-19 pandemic, when students' sleep conditions have been subject to more testing and analysis.
“The early start system forces students to sleep less, which in turn affects their learning ability.”
Many schools have also begun to rethink class start times, such as a school in New Zealand that adjusted the start time to 10:30 in 2006 so that students could get more sleep. This change resulted in a significant drop in student absenteeism. In a high school in Denmark, in order to allow students to get quality sleep, at least one class is arranged every year that starts at 10 o'clock or later.
On the whole, sleep is not only a rest for the body, but also a boost to learning. With these latest studies, educational institutions should pay more attention to students' sleep needs in order to improve learning outcomes and academic achievement. So should we rethink and optimize our daily routine to make learning more effective?
