Losing sleep makes your brain work demonstrably slowly at the cellular level, according to a new study.
The study, published Monday inNature, found that the neurons in key brain cells in your temporal lobe fire more slowly and weakly when you're tired. In other words, losing sleep makes your brain work demonstrably slowly at the cellular level, which has some pretty big effects on what you're capable of accomplishing.
“We discovered that starving the body of sleep also robs neurons of the ability to function properly,” UCLA's Dr. Itzhak Fried said in a university news release. This can lead to "cognitive lapses." If you've ever struggled to complete simple tasks and felt incredibly stupid after a restless night, you're not imagining things—the neurons in your brain are also tired as hell.
The study showed that these effects largely manifested in memory and cognition problems, like taking visual data and transferring it to actual thoughts. In daily life, this is a huge inconvenience, and could even be dangerous; the researchers imagined a scenario in which a pedestrian steps in front of a sleep-deprived driver's car, and the driver's brain can't process the information quickly enough. In fact, the slips in cognition and sluggish reaction time from sleep loss come across in much of the same way as being drunk.
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"Severe fatigue exerts a similar influence on the brain to drinking too much,” Fried said. “Yet no legal or medical standards exist for identifying overtired drivers on the road the same way we target drunk drivers.”
Fried's team used a sample of 12 patients who were about to go under surgery for epilepsy (his specialty is epilepsy research and neurology). Surgeons keep the patients awake all night to try to provoke a seizure, and during the process, they gave the patients a test in visual cognition, which entailed categorizing images as quickly as possible) Sure enough, as the patients got more and more sleep deprived, they got worse at the tests.
Part of the problem, Fried said, is that when you're severely sleep deprived, parts of your brain just give up. Fried explained that during the tests, the researchers observed "slow, sleep-like" patterns disrupting the brain's activity, which suggested that "select regions of the patients’ brains were dozing, causing mental lapses, while the rest of the brain was awake and running as usual.”
The fact that sleep loss ruins your health is pretty common knowledge: It can literally make you fat, cause heart disease, and a whole host of other problems. But the UCLA study sheds particularly light on why you feel so much dumber when you're tired. Be smart, and get some sleep.
