Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.
How Does Sleep Affect Memory Consolidation? | What Happens if I Regularly Lose Sleep? | Sleep, Memory Consolidation, and Aging | How Much Sleep Do We Need? |
Overview
Many of us struggle to achieve higher productivity in an increasingly fast-paced world, especially at work. We aim for a pay raise, a promotion, or acknowledgment.
In the quest for our goals, we ignore our health, eat junk food, spend less time with family, and don’t sleep enough.
These habits cause us to suffer physical and mental setbacks, including forgetfulness, a shorter attention span, and emotional distress.
Hearing health professionals or even motivational speakers talk about sleep is very common. Many of us know sleep is good for us. But what does it really do?
For one, getting a higher quality and quantity of sleep helps with memory consolidation. Studies show that we remember better what we’ve learned and are primed to learn better the following day if we’ve slept well.
How Does Sleep Affect Memory Consolidation?
Sleep occurs in stages that last 90 minutes each: Stage 1 Non-rapid eye movement (NREM), Stage 2 NREM, Stage 3 NREM, and REM (Rapid Eye Movement).
Memory consolidation is the process of fixing a memory in place in your brain. It occurs during the NREM stages of sleep. When you sleep after learning, what you have learned is fixed into your memory. When you sleep before learning, you are more likely to learn better and understand the information you are processing. Studies show that inefficient sleep significantly lowers a person’s learning ability.[1]
As you go through the day, you experience many things. Memories at this time are fresh. Sleeping well and long enough allows the brain to go through all the information processed throughout the day, retain what is important, and discard the rest.
As the stages of sleep progress, the memories the brain has selected to be retained are consolidated or made more stable in the brain, making it easier to recall the information the following day.
The process of memory consolidation continues into the REM stage of sleep. Dreaming occurs at this stage, which is the stage where emotional memories are processed.
In the REM stage of sleep, the brain connects the memories that have been retained, allowing you to form networks of information that build upon each other. This function of REM sleep may help with problem-solving or creating new ideas while you sleep.
What Happens if You Regularly Lose Sleep?
Sleep is a process that sparks benefits that course through the entire body. But a lot of the benefits of sleep majorly affect brain function.
Just as studies have shown that sleep positively affects memory consolidation, they have also shown that lack of quality sleep negatively affects the body.[2]
Poor sleep makes information more difficult to recall. Lack of sleep robs the body of its opportunity to consolidate memories. If memories are not correctly consolidated, they are easily dismissed from the brain, making information much more difficult to recall. You may become more easily confused and are more likely to form false memories. It becomes more challenging to focus, be alert, and pay attention.
You are more likely to make poorer choices when you lose sleep. To make a good decision about something, you need to be able to objectively look at an issue, assess all available options, make an appropriate plan, and make a choice. This process becomes difficult or impaired when you lack sleep.
You experience physical and mental exhaustion when you lose sleep, making you likely to not function well. Whether this is at work or school, you are more likely to make mistakes due to a lack of focus. Some of these mistakes may be minor and easily reversible, but others could cause accidents or injury to yourself or others.
Sleep, Memory Consolidation, and Aging
Studies have shown that the link between deep sleep and memory seen in younger adults may be changed or deteriorated in older adults.[3] The brain changes as you age which affects learning and memory.
As you grow older, your ability for deep sleep gradually reduces, which proportionally affects your ability to consolidate and recall memories effectively.
Older people in their late thirties and older sleep less deeply than younger adults in their early twenties, which automatically translates to them being less likely to remember information.
How Much Sleep Do We Need?
Health experts have said that we should ideally get 7 to 8 hours of sleep every night to achieve numerous benefits for our health.[4]
However, children require more sleep. Depending on how young they are, they need many more hours of sleep than adults. More hours of sleep for children means more learning ability for them in school and everyday life and better growth and development. They experience the highest benefits of memory consolidation after sleep.
Here are the daily sleep requirements for each age bracket:
- Infants and Toddlers: 11 to 17 hours
- Children 3 to 13 years: 9 to 13 hours
- Teenagers: 8 to 10 hours
- Adults: 7 to 9 hours
- Older Adults: 7 to 8 hours
It’s essential to have these timelines because, just as too little sleep has adverse effects on our memory, too much sleep negatively affects our memory.
What’s the Takeaway?
Sleep has many benefits for the entire body, but even more so for the brain. The amount and quality of sleep you have directly impacts memory consolidation. Poor sleep leads to defects in overall performance. Excessive sleep causes defects in cognitive function as well.
Aim for the recommended number of hours to sleep and allow yourself to rest. Please consult your doctor immediately if you have trouble falling or staying asleep.
References:
- U.S. Department of Health and Human Services. (2017, July 13). Sleep on it. National Institutes of Health. Retrieved February 22, 2023, from https://newsinhealth.nih.gov/2013/04/sleep-it
- Rasch, B., & Born, J. (2013). About Sleep’s Role in Memory. Physiological Reviews, 93(2), 681-766. https://doi.org/10.1152/physrev.00032.2012
- Harand, C., Bertran, F., Doidy, F., Guénolé, F., Desgranges, B., Eustache, F., & Rauchs, G. (2011). How Aging Affects Sleep-Dependent Memory Consolidation? Frontiers in Neurology, 3. https://doi.org/10.3389/fneur.2012.00008
- Ferrara, M., & De Gennaro, L. (2001). How much sleep do we need?. Sleep medicine reviews, 5(2), 155–179. https://doi.org/10.1053/smrv.2000.0138
