How Sleep Affects Your Brain

Written by Sabine Downer

Normal sleep affects your brain by re-energizing cells in the body, clearing out waste in the brain, supporting learning and memory, and regulating mood, appetite, and libido [3]. Conversely, sleep deprivation (or extended wakefulness) can have many negative impacts on your brain. In addition to how sleep affects your brain, studies have also shown that sleep deprivation and disruptions like working the night shift can have many negative health effects on the body [1]. These risks include predisposition to certain cancers, diabetes, and heart disease.

Sleep is a very complex process. Briefly, the brain generates two types of sleep [3]. The first type is slow-wave sleep (SWS) which is also called deep sleep. The second type of sleep is rapid eye movement sleep (REM), also called dreaming sleep. Sleep occurs in phases of both SWS and REM, with most time spent in SWS. Different parts of the brain work to create the different types of sleep.

Slow-Wave Sleep: Slow brain waves, relaxed muscles, slow breathing, rest and recovery [3]

Rapid Eye Movement Sleep: Follows SWS, loss of consciousness, muscle paralysis, erratic heart rate and breathing, dreaming occurs, purpose is unknown [3]

Sleep deprivation can trigger complex changes in brain activity and connectivity [2]. Neural network instability from sleep deprivation can be especially impactful on your brain’s working memory functions. Brain changes from lack of sleep also lead to behavioral disruptions, especially in cognition. In some ways, the sleep deprived brain will work to compensate and preserve functions like task performance. The line between adaptive and maladaptive brain function in sleep deprived people can be hard to define. Indeed, much has yet to be learned about how the brain recovers from chronic sleep deprivation.

Researchers have learned that different parts of the brain are not equally impacted by sleep deprivation [2]. An individual’s unique genetics can also impact their response to lack of sleep. That means, for example, that some people may retain their attentiveness when sleep deprived but may suffer more impact to their learning and memory. What is certain is that sleep deprivation affects your brain’s neurologic and psychiatric functions overall. Whether you experience short-term sleep disruption or chronic sleep deprivation it does affect your brain in some adverse manner. That is why good sleep habits are a foundation of good health.



1- Downer, S. Long Term Effect of Working the Night Shift – Sleep Science News. Published 2018. Accessed June 20, 2021 from

2- Krause AJ, Simon EB, Mander BA, et al. The sleep-deprived human brain. Nat Rev Neurosci. 2017;18(7):404-418. doi:10.1038/nrn.2017.55 Accessed June 20, 2021 from

3- Peever, J, and Murray, BJ. What Happens In the Brain During Sleep? Scientific American Mind. 2015;26(5):70-70. doi:10.1038/scientificamericanmind0915-70a Accessed June 20, 2021 from ‌


Image: by Andrea Piacquadio from Pexels

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Sabine Downer

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