How Sleep Quality Affects Memory Consolidation

Have you been forgetful lately? Harness the power of sleep to effortlessly retain information.

Daniesha Govender
By Daniesha Govender
Jovan Mijailovic
Edited by Jovan Mijailovic

Updated May 14, 2024.

A man sleeping to improve memory.

In this article

The connection between sleep and memory

Brain areas that affect memory consolidation

How to measure sleep quality

Sleep quality and cognitive function

Show More

Did you know your sleep might be able to help you effortlessly retain new information and recall past experiences with crystal clarity?

That's right. Research shows that quality shut-eye significantly impacts how well your brain consolidates memories. [1] So, let's see how you can prioritize a good night's rest. It could be the memory hack you've been searching for.



Key takeaways

  • Slow-wave (SWS) and rapid eye movement (REM) are both crucial for memory consolidation. SWS helps store factual memories, while REM sleep solidifies procedural skills and integrates new information with existing knowledge.

  • Quality rest is essential for optimal cognitive function beyond memory. It improves focus, attention, emotional regulation, decision-making, problem-solving, and even creativity.

  • Poor habits can significantly hinder memory consolidation. To optimize memory function, aim for uninterrupted, quality sleep.



The connection between sleep and memory

There's a clear relationship between sleep stages and information retention. [1] For example, the brain uses the slow-wave (SWS) phase to store declarative facts you learn during the day.

In contrast, rapid eye movement (REM) helps solidify procedural memories, like how to ride a bike. During REM, noradrenaline and serotonin levels decrease. This reduction downscales unnecessary synaptic connections to optimize storage for important things you've learned. [1]

REM might also help you integrate new details with existing knowledge. That's why researchers think this process contributes to creativity and problem-solving skills. [1]

Note: Quality shut-eye is essential for memory consolidation. The most beneficial way to do this is to get a good portion of SWS early in the night followed by REM soon after. [2]

» Learn why you should become a sleep architect

Brain areas that affect memory consolidation

Four key regions in your brain play a part in consolidating memory:

  • Hippocampus: This region acts as a temporary storage for new memories. During sleep, it replays their memories, reinforcing the connections between neurons and solidifying the information trace.
  • Neocortex: This is the outer layer of the brain believed to bolster links from the hippocampus project to specific areas for long-term storage.
  • Pre-frontal cortex: Some studies suggest that it could be involved in storing specific types of memories, particularly declarative ones. [3]
  • Amygdala: This almond-shaped structure in the brain is heavily involved in processing emotions, particularly fear and reward. [4] When an experience has a vital emotional component, the amygdala flags it for importance.

» Explore how sleep affects your biomarkers

How to measure sleep quality

Several methods exist to evaluate sleep quality and its impact on memory consolidation:

  • Polysomnography: This approach measures brain waves, blood oxygen, heart rate, breathing, and movement. It provides a comprehensive picture of your sleep stages and how often you wake up during the night.
  • Actigraphy and sleep diaries: Uses a wristwatch-like device to monitor your motion when unconscious.
  • Diaries: Involve writing down sleep and wake times, along with any disruptions.
  • Fitness Trackers: Many fitness trackers offer sleep monitoring. You can sync InsideTracker with your Oura Ring, Apple Watch, Garmin, or FitBit and combine this data with your bloodwork and DNA information. This gives you a more holistic view of your health and performance.


Sleep quality and cognitive function

While quality sleep is essential for memory consolidation, its benefits extend far beyond. It's also vital for optimal cognitive function, as the brain uses it to clear waste products and strengthen neural connections.

Here are some of the advantages of sufficient rest:

  • Sufficient shut-eye improves our ability to concentrate on a task and filter out distractions.
  • It affects emotional regulation and decision-making.
  • It's also beneficial for problem-solving and critical and creative thinking.

Impact of sleep disorders

There are many ways that sleep disorders affect memory consolidation. For example, people with insomnia often deprive the brain of this crucial period. They don't have enough time to file away new information correctly.

People with sleep apnea experience frequent breathing interruptions that disrupt the continuity of their rest. [5] This reduces the duration of both SWS and REM phases, hindering the information storage.

Treatments for sleep disorders

Various treatments can restore healthy sleep patterns, promoting a return to adequate REM and SWS stages. For sleep apnea, continuous positive airway pressure (CPAP) therapy is a highly effective treatment. It uses a mask to deliver constant air to keep the pathway open throughout the night.

On the other hand, some approaches can also help manage insomnia. Cognitive behavioral therapy (CBT-I) is a drug-free method that addresses underlying negative thoughts and behaviors of insomnia. [6]

A woman improving memory by sleeping.


» Explore the relationship between menopause and insomnia

How much shut-eye do you really need?

While most adults function best on a certain amount of sleep, it's not a one-size-fits-all answer. CDC recommends the following [7]:

Age groupAgeRecommended hours of sleep
Infant4–12 months12–16 hours/day (including naps)
Toddler1–2 years11–14 hours/day (including naps)
pre-school3–5 years10–13 hours/day (including naps)
School age6–12 years9–12 hours/day
Teen13–18 years8–10 hours/day
Adult18–60 year7 or more hours/day
Remember, these are general recommendations. Some individuals may require more or less sleep to feel their best.

Tips to improve sleep quality

Here are some of the ways you can improve sleep quality to improve your memory:

1. Regulate your light exposure

Get plenty of bright light during the day, ideally sunlight. This helps regulate your circadian rhythm, your body's internal clock that controls sleep-wake cycles. [8]

In the evening, limit your exposure to screens from devices like phones and laptops. These emit blue light, which can suppress melatonin production, a hormone that signals sleepiness. [9]

2. Limit stimulants and alcohol

Avoid stimulants close to bedtime, as both can interfere with sleep. Caffeine can stay in your system for several hours, so avoid it in the afternoon and evening. [10]

On the other hand, alcohol makes you feel drowsy at first, but it wakes you up later in the night. It affects the body's natural cycle by affecting the chemicals involved, which is especially bad after periods of heavy drinking. [11]

» Find out how alcohol hinders your athleticism

3. Stick to a sleep schedule

Studies suggest that irregular sleep patterns affect your melatonin. Try to go to bed and wake up at consistent times each day, even on weekends. This helps keep your circadian rhythm on track. [12]

» Check out how you can get more sleep without changing your bedtime

4. Optimize your sleep environment

Make sure your bedroom is cool, dark, and quiet. Invest in blackout curtains or an eye mask to block out light. Numerous studies also suggest that noise causes poor sleep and health issues later on. You can try using earplugs to silence any annoying sounds. [13,14]

5. Exercise regularly

Regular physical activity can improve sleep quality, but avoid strenuous workouts close to bedtime as they can be stimulating. One study found that exercise provided 41 more minutes of rest each night for the participants. [15]



Quality sleep: The key to locking in memories

A good night's sleep isn't just a luxury, it's essential for solidifying memories and optimizing cognitive function. During SWS and REM, the brain strengthens connections crucial for storing new information.

At the same time, a lack of shut-eye disrupts this process, hindering your ability to recall what you've learned. By prioritizing quality rest, you're giving yourself the power to transform short-term facts into long-lasting knowledge.

You can also use InsideTracker Ultimate Plan to identify vitamin D and magnesium, which play a role in sleep regulation. After analyzing your bloodwork, the platform generates science-backed recommendations to optimize these and other biomarkers so you can live healthier, longer.




References:

[1] P. Dahat et al., “Correlation of various sleep patterns on different types of memory retention: A Systematic review,” Curēus, Jul. 2023, doi: 10.7759/cureus.42294. Available: https://pubmed.ncbi.nlm.nih.gov/37614274/

[2] A. K. Patel, V. Reddy, K. R. Shumway, and J. F. Araujo, “Physiology, sleep stages,” StatPearls - NCBI Bookshelf, Jan. 26, 2024. Available: https://www.ncbi.nlm.nih.gov/books/NBK526132/

[3] S. Sridhar, A. Khamaj, and M. K. Asthana, “Cognitive neuroscience perspective on memory: overview and summary,” Frontiers in Human Neuroscience, vol. 17, Jul. 2023, doi: 10.3389/fnhum.2023.1217093. Available: https://pubmed.ncbi.nlm.nih.gov/37565054/

[4] P. Sah, “Fear, anxiety, and the amygdala,” Neuron, vol. 96, no. 1, pp. 1–2, Sep. 2017, doi: 10.1016/j.neuron.2017.09.013. Available: https://pubmed.ncbi.nlm.nih.gov/28957662/

[5] E. Csábi, M. Varszegi-Schulz, K. Janacsek, N. Malecek, and D. Németh, “The consolidation of implicit sequence memory in obstructive sleep apnea,” PloS One, vol. 9, no. 10, p. e109010, Oct. 2014, doi: 10.1371/journal.pone.0109010. Available: https://doi.org/10.1371/journal.pone.0109010

[6] S. Sridhar, A. Khamaj, and M. K. Asthana, “Cognitive neuroscience perspective on memory: overview and summary,” Frontiers in Human Neuroscience, vol. 17, Jul. 2023, doi: 10.3389/fnhum.2023.1217093. Available: https://doi.org/10.3389/fnhum.2023.1217093

[7] “#Sleep for good health,” Centers for Disease Control and Prevention, Mar. 04, 2024. Available: https://www.cdc.gov/sleep/features/getting-enough-sleep.html

[8] S. S. Campbell, D. Dawson, and M. W. Anderson, “Alleviation of Sleep Maintenance Insomnia with Timed Exposure to Bright Light,” Journal of the American Geriatrics Society, vol. 41, no. 8, pp. 829–836, Aug. 1993, doi: 10.1111/j.1532-5415.1993.tb06179.x. Available: https://pubmed.ncbi.nlm.nih.gov/8340561/

[9] J. J. Gooley et al., “Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans,” ˜the œJournal of Clinical Endocrinology and Metabolism/Journal of Clinical Endocrinology & Metabolism, vol. 96, no. 3, pp. E463–E472, Mar. 2011, doi: 10.1210/jc.2010-2098. Available: https://pubmed.ncbi.nlm.nih.gov/21193540/

[10] C. L. Drake, T. Roehrs, J. R. Shambroom, and T. Roth, “Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed,” Journal of Clinical Sleep Medicine, vol. 09, no. 11, pp. 1195–1200, Nov. 2013, doi: 10.5664/jcsm.3170. Available: https://pubmed.ncbi.nlm.nih.gov/24235903/

[11] M. Thakkar, R. Sharma, and P. Sahota, “Alcohol disrupts sleep homeostasis,” Alcohol/Alcohol (Amsterdam. Online), vol. 49, no. 4, pp. 299–310, Jun. 2015, doi: 10.1016/j.alcohol.2014.07.019. Available: https://pubmed.ncbi.nlm.nih.gov/25499829/

[12] J. S. Emens, K. Yuhas, J. N. Rough, N. Kochar, D. Peters, and A. J. Lewy, “Phase Angle of Entrainment in Morning‐ and Evening‐Types under Naturalistic Conditions,” Chronobiology International, vol. 26, no. 3, pp. 474–493, Jan. 2009, doi: 10.1080/07420520902821077. Available: https://ncbi.nlm.nih.gov/pmc/articles/PMC2699216/

[13] T. Bodin, J. Björk, J. Ardö, and M. Albin, “Annoyance, Sleep and Concentration Problems due to Combined Traffic Noise and the Benefit of Quiet Side,” International Journal of Environmental Research and Public Health/International Journal of Environmental Research and Public Health, vol. 12, no. 2, pp. 1612–1628, Jan. 2015, doi: 10.3390/ijerph120201612. Available: https://pubmed.ncbi.nlm.nih.gov/25642690/

[14] K. A. Lee and C. Gay, “Can modifications to the bedroom environment improve the sleep of new parents? Two randomized controlled trials,” Research in Nursing & Health, vol. 34, no. 1, pp. 7–19, Nov. 2010, doi: 10.1002/nur.20413. Available: https://pubmed.ncbi.nlm.nih.gov/21243655/

[15] “Moderate-intensity exercise and self-rated quality of sleep in older adults. A randomized controlled trial,” PubMed, Jan. 01, 1997. Available: https://pubmed.ncbi.nlm.nih.gov/8980207/