New Study Suggests Sleep Resets the Brain Like a Computer

Updated February 2, 2024

Fact-Checked

The Sleep Foundation editorial team is dedicated to providing content that meets the highest standards for accuracy and objectivity. Our editors and medical experts rigorously evaluate every article and guide to ensure the information is factual, up-to-date, and free of bias.

The Sleep Foundation fact-checking guidelines are as follows:

We only cite reputable sources when researching our guides and articles. These include peer-reviewed journals, government reports, academic and medical associations, and interviews with credentialed medical experts and practitioners.
All scientific data and information must be backed up by at least one reputable source. Each guide and article includes a comprehensive bibliography with full citations and links to the original sources.
Some guides and articles feature links to other relevant Sleep Foundation pages. These internal links are intended to improve ease of navigation across the site, and are never used as original sources for scientific data or information.
A member of our medical expert team provides a final review of the content and sources cited for every guide, article, and product review concerning medical- and health-related topics. Inaccurate or unverifiable information will be removed prior to publication.
Plagiarism is never tolerated. Writers and editors caught stealing content or improperly citing sources are immediately terminated, and we will work to rectify the situation with the original publisher(s)
Although Sleep Foundation maintains affiliate partnerships with brands and e-commerce portals, these relationships never have any bearing on our product reviews or recommendations. Read our full Advertising Disclosure for more information.

It’s well known that sleep combats tiredness 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. View Source and is essential for thinking and feeling your best. But why exactly do you need sleep? And how does sleep affect your brain? A recent study sheds light on the role of ‘criticality’ in answering these important questions about sleep.

Criticality is a term used across scientific fields to describe a state in which systems are at their most flexible, 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. View Source and capable of carrying out complex tasks. In physics, criticality is the moment a system is perfectly balanced at the brink of a major change, an instant between order and chaos.

In the brain, scientists propose that networks of brain cells called neurons achieve criticality at the tipping point 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. View Source between bursts of electrical activity. In essence, criticality is a moment when activity in your brain is balanced and unimpeded and your ability to process information is at its peak.

By monitoring the brain activity of young rats, researchers at Washington University in St. Louis sought to find evidence that restoring your brain to criticality may be one of the main functions of sleep.

Researchers measured brain activity during both wakefulness and sleep, calculating how far the rats’ brains were from a state of criticality at different points over 10 to 14 days.

The study found several interesting patterns. During waking hours, they found that brain activity moved progressively further from criticality, but only when the rats spent time under lights.

Sleep, on the other hand, appeared to bring the brains closer to criticality.

Similar to resetting a computer to improve its performance, these findings suggest that sleep may help return the brain to a balanced state for optimal functioning the next day. This reinforces the idea that sleep is an active process that is necessary for your health, not merely a passive state of rest.

While this study opens exciting possibilities about the role of sleep, it’s important to note its limitations. Conducted on young rats, the research leaves questions about how these findings might translate to people. Also, criticality is a difficult theory to prove with certainty, so continued research is needed to deepen our understanding of how and why we sleep.

Got a hot tip? Pitch us your story idea, share your expertise with SleepFoundation.org, or let us know about your sleep experiences right here.

Written By

Rob Newsom, Staff Writer

Rob writes about the intersection of sleep and mental health and previously worked at the National Cancer Institute.

Learn more about our Editorial Team

References
4 Sources

National Institute of Neurological Disorders and Stroke. (2023, July 19). Brain basics: Understanding sleep., Retrieved January 28, 2024, from
https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-understanding-sleep
Scarpetta, S., Morisi, N., Mutti, C., Azzi, N., Trippi, I., Ciliento, R., Apicella, I., Messuti, G., Angiolelli, M., Lombardi, F., Parrino, L., & Vaudano, A. E. (2023). Criticality of neuronal avalanches in human sleep and their relationship with sleep macro- and micro-architecture. iScience, 26(10), 107840.
https://pubmed.ncbi.nlm.nih.gov/37766992/
Xu, Y., Schneider, A., Wessel, R., & Hengen, K. B. (2024). Sleep restores an optimal computational regime in cortical networks. Nature Neuroscience.
https://www.nature.com/articles/s41593-023-01536-9
Irani, M., & Alderson, T. H. (2023). Tuning criticality through modularity in biological neural networks. The Journal of Neuroscience, 43(33), 5881–5882.
https://pubmed.ncbi.nlm.nih.gov/37586856/