How Sleep Affects Brain Function
From improving your mood, memory, and attention to learning more effectively, this is how your brain benefits from a night of good night sleep.
Dr. Corina Kibsey

Dr. Corina Kibsey

Naturopathic Medicine Doctor

We all know how we feel after a good night’s sleep. Like we could take on the world.  

We now have the research to show us just how important it is to get a good night’s rest.

Studies have shown that adequate sleep that is timed appropriately is important for numerous biological processes and systems. (1)

Research also shows that sleep plays an important role in emotional memory and decision-making. When someone experiences insomnia, this affects their mood and ability to make decisions. (2)

What happens when we sleep

Benefits of sleeping

Improves your mood

Rapidly emerging evidence continues to show that there is an intimate relationship between sleep and your emotional brain function. For many years, clinicians have observed the co-occurrence between insomnia and almost all mood and anxiety disorders. Sleep helps by preparing you for social and emotional functioning the next day. (3)

Improves your memory

There is strong evidence to suggest that sleep plays a role in memory consolidation. What memory consolidation involves is stabilizing memories into long-term storage. It also involves integrating new information into existing memories.

One study found that during a 12 hour retention period that is spent in sleep benefits memory, compared to in subjects who spent most of the 12 hour period awake. (4)

Allows you to learn more effectively

One study found that skills only improved when the 12 hour period between learning and testing the skill included sleep. Researchers have stated that learning is absolutely sleep-dependent, particularly NREM, or non-rapid eye movement sleep. (5)

Improves your attention

Studies have shown that longer sleep improves sustained attention, meaning that when you get a proper night’s rest you are better able to hold your attention and focus the next day. (6)

Sleep deprivation


Sleep deprivation is generally considered to be less than six hours of sleep per night. (7)

It’s not just about the number of hours, though. Sleep deprivation occurs when inadequate sleep leads to next-day or long-term consequences, such as decreased performance, inadequate alertness, and deterioration in health. (8)

Sleep deprivation also has to do with the time of day at which you are sleeping. Is your sleep meeting your body’s needs? If your sleep is not timed properly with the body’s circadian rhythms, then this is still considered sleep deprivation. One example would be people who work night shifts. (9)

There are several common causes of sleep deprivation, some of which are within our realm of control, and some of which are not. One example is puberty, which is a time when sleep deprivation can naturally occur.

Other common causes of sleep deprivation include work, school, studying, anxiety, caffeine intake, having to wake up early, and evening use of electronic media and screens.

What happens when we do not sleep enough

Attention and focus change

Sleep deprivation has been shown to decrease your ability to hold your focus and attention. One study found that insomnia is associated with impairments in complex attention as well as alertness. (10)

Memory starts to fail

Sleep deprivation can also be detrimental to your brain’s ability to form and integrate memories. One study found that insomnia is associated with issues in both retention and capacity in working memory as well as episodic memory. (11)

Learning becomes difficult

Sleep deprivation can lead to difficult and inefficient learning. Researchers have found that insomnia causes serious cognitive and emotional consequences in learning. (12)

We become cranky

Sleep deprivation can make us feel irritable. Research has shown that irritability and fatigue occur during the day when we are getting insufficient sleep at night. Whether it’s due to difficulty initiating sleep or staying asleep, insomnia can lead to irritability during the waking hours. (13)

Toxins start feeling comfortable

Sleep deprivation can slow down the clearing of toxins, including those that are associated with Alzheimer’s disease. These are called amyloid-beta oligomers, and they build up in the brains of people with Alzheimer’s disease, leading to synapse damage and memory impairment.

A study looked at chronically sleep-restricted mice and found that they exhibited increased susceptibility to amyloid-beta oligomers. They then had poorer performance on an object recognition memory task. (14)

Tips for improving sleep quality


A good quality sleep translates into a healthy, well-functioning brain. In fact, researchers have found that there may be important connections between brain energy metabolism and the need to remove metabolic waste products. (15)

Establish a sleeping routine


Sleep routine is a good practice because you are training your body to know when it is time to prepare for bed. It’s best to start this in infancy and continue it throughout childhood, but it’s even good to have a bedtime routine as an adult.

The American Academy of Pediatrics recommends that parents promote good sleep hygiene, with a sleep-promoting environment and a bedtime routine. (16)

Clean your body from caffeine the 2nd half of the day


Research has demonstrated that caffeine prolongs the amount of time it takes to fall asleep, reduces the total sleep time, reduces sleep efficiency, and worsens the perceived quality of sleep. A timing-response relationship has been established, which means that the closer to bedtime that you consume caffeine, the worse the effects of caffeine on your sleep will be. (17)

Try a warm bath

Your body needs to drop in temperature a little bit before you go to sleep. That’s why a well-timed warm bath can help assist in the temperature drop.

One study looked at subjects with a self-reported sleep disturbance. Their body temperatures and polysomnography were recorded for three nights in a row. They were given a 41 degree Celsius bath for 40 minutes before going to sleep. Results showed that on the night where subjects had a warm bath, their wakefulness decreased and the amount of sleep increased. (18)


Reading can help to calm the brain before bed – but only if you’re not reading from a screen! (19) Research has shown that computer usage for reading is associated with insomnia, but that reading from an actual physical book does not have these effects. (20)

Change your workout routine


Exercise has been shown time and time again to improve sleep overall. However, scheduling exercise too close to bedtime can contribute to insomnia. The best rule to follow is to keep your exercise before the late afternoon at the latest. Exercise first thing in the morning is best. (21)


Good sleep is crucial to good health. Good quality sleep has several benefits, including better memory, increased attention and focus, more efficient learning, and better mood.

If you don’t get proper sleep, you could suffer from poor memory, a decreased ability to focus, a harder time learning new skills, and feeling cranky.

To avoid these unwanted effects, make sure you establish a bedtime routine. You’ll also want to stay away from caffeine, particularly in the second half of the day. Try having a warm bath before bed. Read a book before you go to sleep, but not on a computer or screened device. Finally, exercise, but keep it earlier in the day.


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