Scientists and researchers have studied the relationship between memory and sleep Trusted Source National Institutes of Health (NIH) The NIH, a part of the U.S. Department of Health and Human Services, is the nation’s medical research agency — making important discoveries that improve health and save lives. See Full Reference for more than 100 years. The general consensus today is that memory consolidation Trusted Source National Institute of Neurological Disorders and Stroke (NINDS) NINDS aims to seek fundamental knowledge about the brain and nervous system and to use that knowledge to reduce the burden of neurological disease. See Full Reference – the process of preserving key memories and discarding excessive information – takes place during both the non-rapid eye movement (NREM) and rapid eye movement (REM) stages of your sleep cycle.

Recent studies also suggest that insufficient and excessive sleep Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference can affect memory processing and other cognitive processes. A good night’s rest not only promotes good physical health but also enables our brains to function properly, so getting the recommended amount of sleep each night is key to consolidating memories.

How Are Memory and Sleep Connected?

Sleep and memory share a complex relationship. Getting enough rest helps you process new information Trusted Source NIH News in Health The NIH, a part of the U.S. Department of Health and Human Services, is the nation’s medical research agency — making important discoveries that improve health and save lives. See Full Reference once you wake up, and sleeping after learning can consolidate this information into memories, allowing you to store them in your brain.

A healthy adult’s sleep cycle consists of four distinct stages. The first two stages are considered light NREM sleep, and the third is deep (or “slow-wave”) NREM sleep. These three stages prepare your brain to learn new information the following day. Not sleeping or getting enough sleep can lower your learning abilities by as much as 40%.

During these NREM stages, the brain also sorts through your various memories from the previous day, filtering out important memories and eliminating other information. These selected memories will become more concrete as deep NREM sleep begins, and this process will continue during REM sleep. Emotional memories are also processed in the REM stage, which can help you cope with difficult experiences.

Most dreaming occurs in REM sleep. The thalamus of the brain transmits cues from your five senses to the cerebral cortex, a thin layer of the cerebrum that interprets and processes information from your memories. The thalamus is largely inactive during NREM stages, but when REM sleep begins, it will relay images, sounds, and other sensations to the cerebral cortex that are then integrated into your dreams.

How Does Sleep Deprivation Affect Brain Function and Memory?

People who don’t get enough sleep may experience the effects of sleep deprivation. Difficulty remembering things Trusted Source National Heart, Lung, and Blood Institute (NHLBI) The NHLBI is the nation's leader in the prevention and treatment of heart, lung, blood and sleep disorders. See Full Reference is one common symptom. Since the brain does not have sufficient time to create new pathways for the information you’ve recently learned, sleep deprivation often affects how memories are consolidated. Other potential cognitive impacts include trouble learning and focusing, reduced decision-making skills, and poor emotional and behavioral control.

How much sleep you should get each night largely depends on your age. In addition to adults, studies have concluded children experience stronger memory consolidation Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference after a good night’s sleep. That said, excessive sleep can also lead to cognitive impairments. Every person should strive for the optimal amount of nightly sleep, as too little or too much can have negative repercussions.

Our recommendations for nightly sleep based on age are as follows:

Age GroupAge RangeRecommended Amount of Sleep per Day
Newborn0-3 months14-17 hours
Infant4-11 months12-15 hours
Toddler1-2 years11-14 hours
Preschool3-5 years10-13 hours
School-age6-13 years9-11 hours
Teen14-17 years8-10 hours
Young Adult18-25 years7-9 hours
Adult26-64 years7-9 hours
Older Adult65 years or older7-8 hours

Some studies have found sleep quality decreases with age Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference . This is tied to slow-wave sleep. Slow waves are produced in an area of the brain known as the medial prefrontal cortex. The medial prefrontal cortex will deteriorate over time, and as a result, older people typically experience less slow-wave sleep during a normal sleep cycle and have a harder time processing memories.

 

Sleep Apnea and Memory Loss

Since sleep is so crucial to the formation and consolidation of memories, some sleep disorders Trusted Source American Academy of Sleep Medicine (AASM) AASM sets standards and promotes excellence in sleep medicine health care, education, and research. See Full Reference are associated with memory problems. Insomnia, defined as persistent difficulty initiating or maintaining sleep, is known to cause daytime cognitive impairments including reduced memory functioning. Sleep disorders that lead to excessive daytime sleepiness such as narcolepsy can cause memory lapses.

One disorder, sleep apnea, may actually promote memory loss. Sleep apnea is characterized by the temporary cessation of the airway during sleep that can cause people to choke or gasp for air. Heavy snoring and excessive daytime sleepiness are other common symptoms of sleep apnea.

More than 900 million people Trusted Source ScienceDaily ScienceDaily features breaking news about the latest discoveries in science, health, the environment, technology, and more -- from leading universities, scientific journals, and research organizations. See Full Reference across the globe live with obstructive sleep apnea (OSA), a subtype of the disorder that occurs when a physical blockage impedes the airway. OSA has long been linked to chronic depression. People with depression often have a difficult time processing memories, specifically autobiographical memories that pertain to their own experiences. People with OSA have also demonstrated difficulty with memory consolidation.

One study sought to explore the relationship between OSA and depression in terms of memory processing. The findings show subjects with OSA struggled more to form semantic memories, or individual facts from their personal history, than the control group. This is not surprising since healthy sleep is needed to properly consolidate semantic memories, and OSA causes sleep fragmentation that interferes with the sleep cycle. Interestingly, OSA did not affect the consolidation of episodic memories – or those related to events and experiences – to the same extent.

These results suggest sleep apnea can interfere with the memory consolidation process, causing people to have a hard time recalling certain memories of their own life. However, more research is needed to explore whether OSA leads to both depression and memory problems, or if OSA and depression independently affect memory consolidation.

Thanks for the feedback - we're glad you found our work instructive!

Thanks for the feedback - we're glad you found our work instructive!

Submitting your Answer...

References

+10 Sources
  1. National Institutes of Health. (2019, September 19). The brain may actively forget during dream sleep [Press release]., Retrieved November 11, 2020, from

    https://www.nih.gov/news-events/news-releases/brain-may-actively-forget-during-dream-sleep
  2. National Institute of Neurological Disorders and Strokes (NINDS). (2019, August 13). Brain basics: Understanding Sleep., Retrieved November 11, 2020, from

    https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-understanding-sleep
  3. Ma, Y., Liang, L., Zheng, F., Shi, L., Zhong, B., & Xie, W. (2020). Association Between Sleep Duration and Cognitive Decline. JAMA network open, 3(9), e2013573., Retrieved from

    https://pubmed.ncbi.nlm.nih.gov/32955572/
  4. NIH News in Health. Sleep On It. How Snoozing Strengthens Memories. (April 2013)., Retrieved November 11, 2020, from

    https://newsinhealth.nih.gov/2013/04/sleep-it
  5. National Heart, Lung, and Blood Institute. (n.d.). Sleep deprivation and deficiency., Retrieved November 11, 2020, from

    https://www.nhlbi.nih.gov/health-topics/sleep-deprivation-and-deficiency
  6. Peiffer, A., Brichet, M., De Tiège, X. et al. The power of children’s sleep – Improved declarative memory consolidation in children compared with adults. Sci Rep 10, 9979 (2020)., Retrieved from

    https://pubmed.ncbi.nlm.nih.gov/32561803/
  7. Mander, B., Rao, V., Lu, B. et al. Prefrontal atrophy, disrupted NREM slow waves and impaired hippocampal-dependent memory in aging. Nat Neurosci 16, 357–364 (2013)., Retrieved from

    https://pubmed.ncbi.nlm.nih.gov/23354332/
  8. American Academy of Sleep Medicine. (2014). The International Classification of Sleep Disorders – Third Edition (ICSD-3). Darien, IL.

    https://aasm.org/
  9. Science Daily. (2019, January 31). Sleep apnea creates gaps in life memories [Press release]., Retrieved November 11, 2020, from

    https://www.sciencedaily.com/releases/2019/01/190131101103.htm
  10. Delhikar, N., Sommers, L., Rayner, G., Schembri, R., Robinson, S., Wilson, S., & Jackson, M. (2019). Autobiographical Memory From Different Life Stages in Individuals With Obstructive Sleep Apnea. Journal of the International Neuropsychological Society, 25(3), 266-274., Retrieved from

    https://www.cambridge.org/core/product/identifier/S1355617718001091/type/journal_article