As you age, there are normal gaps in your memory that cause you to become a little fuzzy on certain issues. It’s just part of getting older. But if you’ve noticed a change in the way you’re processing and remembering information, and it’s interfering with your daily life, there may be something else going on. That something else could be that you’re just not getting enough sleep and it’s starting to impact your memory. In this article, we’ll analyze the connection between sleep and memory and explore a few common scenarios that link changes in memory with changes in sleep quality.
Sleep and Your Memory
The link between deep sleep and memory has been established for more than a century, with the consensus being the quality and quantity of sleep affects your memory, no matter how old you are. That said, the exact relationship between deep sleep (also known as slow wave sleep) and memory is still being investigated. Despite the unknowns, the general knowledge among scientists is that sleep enhances your brain’s ability to remember information and, therefore, to learn. Conversely, a lack of sleep negatively impacts your ability to secure memories and can interfere with learning. Sleep—and different sleep stages in particular—appear to allow the brain to reprocess newly acquired information into your memory. During this process, memories made during the day are said to be “consolidated,” or crystallized into long-term, stable memories.
Research shows that sleep, primarily light sleep, also influences “motor memories.” Motor memory, also known as procedural memory, refers to the ability to learn physical skills like riding a bike, throwing a baseball, mastering a video game or playing an instrument. Sharp motor memory can help people who are training for a sport or learning new musical pieces on the piano. When you get the right amount of sleep, your skill-based memories become sharper. Motor memories can even benefit from an afternoon nap, which is often dominated by light sleep.
Sleep also improves your recall. Declarative memory refers to the ability to store and recall facts, such as all those dates, places, and events you had to memorize in history class. Research shows that memories of recently learned facts strengthen if sleep occurs between learning and testing. During deep sleep (slow wave sleep), declarative memory appears to be given a particular boost. If you’re a college student, an all-nighter is probably not your best strategy. Your ability to recall facts will be greater if you allow yourself a good night’s rest before an exam.
Holiday travel can give you something known as jet lag which can also impede your memory’s ability to work as well as it should. Under the influence of jet lag, your mind and body drift in and out of a haze—a haze sometimes held at bay with stimulants like caffeine—and when it finally comes time to sleep, you crash hard. This fuzzy-headed, fatiguing cycle repeats for a few days until you get “back on track” a few days later. Scientific research suggests that “getting back on track” may take longer than you think, sometimes more than 28 days! That’s almost the same amount of time it takes to work off a sleep debt.
Perceptions are also greatly influenced by the amount of sleep you get each night. It has been suggested that during REM sleep, the brain processes sensory learning, which can lead to better understanding of the visual, auditory, spatial, and emotional conditions that surround us. Even though sleep can be very beneficial for strengthening memories, it is not a great time for new memories to form. As the body transitions between sleep and wakefulness, the brain’s ability to retain new information shuts down. Case in point: Have you ever woken up late in the morning only to realize that you had turned off your alarm without realizing it? You probably fell asleep again so quickly that your brain had no time to store the memory of the alarm ringing. This may also be the reason why you don’t always remember your dreams, or they tend to fade very quickly in the morning. The transitions between sleep and wakefulness make the formation of new memories a challenge.
There’s no denying the connection between getting proper rest and allowing your memory to work at an optimal level. Shoot for 7 to 8 hours of sleep each night to keep your memory in tip-top order.