A few years ago, I recognized that I wasn’t sleeping enough and it was affecting my work, so I went on a sleep reading binge and researched as much as I could about the topic. There were two books that I found to be really helpful:
“Why We Sleep: Unlocking the Power of Sleep and Dreams” by Matthew Walker
After reading these, among other sources, I made some critical changes to how I prepared myself for a good night’s sleep (which I will share with you toward the end of the article), but first I want to discuss how sleep affects your memory — which in turn affects your ability to learn and retain information.
Sleep is not only essential for physical restoration — it also plays a crucial role in cognitive functions, particularly memory recall. Memory processing, from encoding to consolidation, largely depends on the quality and quantity of sleep we get. Poor sleep habits can impair recall and learning, while good sleep can enhance memory, making it easier to retain and recall information. In this article, we’ll explore five key ways that sleep impacts memory recall, highlighting the science behind these processes and offering tips to optimize sleep for better learning and retention.
Consolidation of New Information
Memory consolidation is one of the most critical processes for memory recall. When we learn something new, the brain initially stores the information in a fragile, temporary state. During sleep, particularly during deep slow-wave sleep and REM (rapid eye movement) stages, the brain replays this information and moves it from short-term to long-term memory. This process solidifies memories, making it easier to access them when needed.
- Science insight: Studies suggest that during deep sleep, the hippocampus reactivates memories, which are then stored in the cortex, enhancing long-term storage.
- Practical tip: Incorporate “sleep on it” as part of your learning routine. After learning something new, ensure you get at least seven to nine hours of sleep to facilitate memory consolidation.
Enhancement of Problem-Solving Skills
Sleep not only helps us retain information, but also enhances our ability to creatively solve problems and make connections between pieces of information. REM sleep, the phase of sleep most associated with dreaming, plays a critical role in integrating new information with existing knowledge, which helps in problem-solving and innovation.
- Science insight: During REM sleep, the brain strengthens associative connections, allowing it to link unrelated information and come up with creative solutions.
- Practical tip: If you’re working on a project or studying a complex topic, consider reviewing it before bed. This primes the brain to work on solutions while you sleep, often leading to clearer insights the next day.
Reduction of Forgetfulness
Lack of sleep can lead to forgetting or misremembering information. When we don’t get adequate sleep, the brain struggles to consolidate memories, leading to fragmented or incomplete recall. Sleep deprivation impairs the prefrontal cortex and hippocampus, both crucial areas for memory and decision-making.
- Science insight: In sleep-deprived individuals, the hippocampus (responsible for memory formation) shows decreased activity, which translates to weaker memory formation and retrieval.
- Practical tip: To avoid forgetfulness, prioritize consistent sleep routines and minimize disruptions, aiming for at least seven hours of continuous sleep each night.
Strengthening Emotional Memory
Sleep plays a role in processing emotionally charged memories, which is essential for both mental health and learning. Studies have shown that emotional memories are better retained after a good night’s sleep, as the brain prioritizes these memories during sleep. This function helps us make sense of emotional experiences and maintain emotional well-being, which is essential for balanced cognitive processing and memory recall.
- Science insight: During REM sleep, the amygdala (a region associated with emotional processing) works with the hippocampus to encode emotional memories deeply.
- Practical tip: If you’ve had an emotionally charged day, focus on getting restful sleep. Relaxation techniques like meditation before bed can enhance your sleep quality, allowing your brain to process and stabilize emotional memories effectively.
Improvement of Working Memory Capacity
Working memory, which allows us to hold and manipulate information in the short term, is highly sensitive to sleep quality. A rested brain is better equipped to process information and make quick decisions. When sleep is inadequate, working memory capacity suffers, making it harder to manage information flow and recall specific details when needed.
- Science insight: Sleep-deprived individuals often struggle with tasks that require active information manipulation, as sleep is integral to maintaining working memory capacity.
- Practical tip: Regular, sufficient sleep strengthens working memory. Avoid studying or working through the night as this can impair both working memory and overall performance.
Final Thoughts + 3 Ways to Improve Your Sleep Quality
As promised, I want to share with you three actions that I took that have drastically improved my sleep quality — and I know this because I use an Oura ring to track my sleep quality.
- Not eating close to bedtime: When I did my research, I found that you should eat your last meal at least three to four hours before bedtime. Eating close to bedtime can cause discomfort from indigestion or bloating, making it harder to fall asleep. A full stomach may also lead to nighttime awakenings or lighter sleep due to increased digestive activity.
- Shower before bed: Showering before bed has many benefits, but the one that is most related to sleep quality is body temperature regulation. A warm shower can help lower your body temperature as it cools down afterward, signaling your body that it’s time to sleep. This process can enhance the release of melatonin, the hormone that regulates sleep.
- Read (fiction) before bedtime: Most of us are glued to our screens from morning to night, which is NOT good for your sleep. Reading a physical book (or using an e-reader with no blue light) avoids the stimulating effects of screens, which can disrupt melatonin production and interfere with sleep. Fiction specifically allows you to escape into another world, reducing stress and helping your mind detach from daily worries. Studies show that reading can lower stress levels more effectively than other relaxation methods like listening to music. Lastly, engaging with a story helps calm racing thoughts, signaling to your brain that it’s time to wind down.
Sleep is a powerful tool that supports memory recall, learning, and overall cognitive function. By prioritizing good sleep hygiene and adopting habits that promote restful sleep, you can improve not only your recall abilities but also your creativity, problem-solving skills, and emotional resilience.
References:
https://www.sciencedirect.com/science/article/pii/S0896627304005409
https://www.nature.com/articles/nrn.2017.55
