Sleep does so much more than refresh us for another day of work and fun. Research suggests that both the quantity and quality of sleep we get affects our memory and how we learn in two specific ways:
- Lack of sleep makes it difficult to maintain one’s attention on a subject, thereby making it difficult to learn.
- The process of sleep is intertwined with our ability to consolidate memories, which is an important part of learning new information.
Therefore, upon learning something new – studying for an exam, learning a new language, training at a new job – the best next steps is to take a nap. Sleep helps you strengthen memories that have been created by linking new information to former memories. The sleeping mind is extremely creative and often helps you create new associations and memory tactics that you may not have considered while awake.
Learning and Memory
Learning new information is often described in these three terms:
- Acquisition: the introduction of new information
- Consolidation: the process of storing new facts
- Recall: the ability to access stored information
Acquisition and recall are functions that are performed only during periods of wakefulness. Consolidation, however, is believed to occur only during sleep. Research shows that during sleep, the neural connections that form our memories are strengthened. While the exact process is still unknown, it is believed that the specific brain waves that occur during different stages of sleep are associated with the formation of memories.
To study the process of consolidation of memories, researchers use two different approaches. In one, they look at the different stages of sleep, along with their duration, and how changes affect learning. The other approach is to examine how sleep deprivation (whether total, partial, or selective) affects the learning process.
The National Institute of Health (NIH) has been funding research to identify and explain the complex relationship between sleep and learning. The hope is that students may be able to access more effective methods of learning and older individuals may have the ability to access memories longer as they age.
“We’ve learned that sleep before learning helps prepare your brain for initial formation of memories,” says Dr. Matthew Walker, who is a sleep scientist at the University of California in Berkeley. “And then, sleep after learning is essential to help save and cement that new information into the architecture of the brain, meaning that you’re less likely to forget it.”
Types of Sleep
Sleep can be broken down into three distinct phases, known as light sleep, slow-wave sleep, and rapid eye movement sleep.
Light sleep: LIghter stages of sleep appear to be related to motor learning. Visual learning, on the other hand, is typically associated with the quantity and timing of SWS and REM sleep.
Slow-wave Sleep (SWS): The deep, restorative sleep of SWS consists of non-REM sleep and is believed to have a connection to the processing of recently learned material.
Rapid Eye Movement (REM): The stage of sleep in which dreaming occurs, which is believed to be involved in memory and learning consolidation.
Types of Memory
In studying learning and sleep, scientists have found that there is a correlation between the type of memory and the stage of sleep.
Declarative Memory: This is the knowledge of fact-based information, such as “what” we know. For instance, Jefferson City is the capital of Missouri. Or the fact that you ate fried chicken for dinner last night. Scientists believe that REM sleep is involved in processing declarative memories, particularly in situations where the information is complex or emotional.
Procedural Memory: Procedural memory refers to the memories associated with a procedure, such as how to bake a pie or how to play level 3 of that video game. Like with declarative memories, REM sleep appears to be related to the consolidation of procedural memories.
Effects of Sleep Deprivation
Lack of sleep can cause various problems with learning and recall. The most obvious problem is that when we miss out on sleep, we tend to easily lose our focus and ability to maintain attention. This makes it difficult to access new information. But beyond that, even if we are able to focus long enough to receive new information, we may be unable to maintain it. Overworked neurons cannot function properly, making us unable to access memories or store new learned materials.
Being tired can affect our interpretation and judgement. We are unable to properly evaluate a situation and may therefore make unsound decisions related to information and events. We may also experience muscle fatigue, our neurons may not fire effectively, and even our organs may function improperly or without being attuned to each other.
Sleep deprivation or low-quality sleep also affects mood. We’ve all experience a bad night of sleep only to awake feeling groggy and grumpy. Even coffee does not seem to help. A low mood can not only affect one’s outlook, it can damage one’s relationships and impair one’s ability to even feel like learning new information.
Researchers and scientists still have questions regarding how sleep helps you learn, but evidence does show a distinct relationship between the two. The various sleep stages clearly affect the consolidation of memories, while lack of sleep certainly interferes with one’s ability to learn, maintain, and recall information. Adequate sleep is necessary to continue to learn and grow as well as to remember what you’ve already learned.