Sleep Deprivation and the Brain
Those that don’t get enough sleep at night tend to notice a difference the next day. They are more drowsy than usual, and concentrating seems like a much more difficult task than usual. Studies have shown that it can also lead to impaired memory and physical performance; it can even reduced one’s ability to carry out mathematical calculations. All of which can affect you greatly during seemingly simple, everyday tasks.
If sleep deprivation continues even worse occurrences begin to unfold; hallucinations and mood swings can develop. Activity in the parts of the brain that control emotions, decision-making, and social interactions in a way “go to sleep” when we go to sleep. This gives them a chance to refresh, helping us maintain optimal emotional and social functions when we then wake up. In more technical terms it is believed that sleep allows neurons to shut down and repair themselves for a time. Without this shutdown time the neurons could end up so depleted of energy and polluted with byproducts from other cellular activities that they can begin to malfunction.
Losing Brain Cells
A number of studies that look at the brains of both humans and mice have come accross findings about the necessity of sleep for normal brain function. One such study in The Journal of Neuroscience found that sleep deprivation leads to brain cell loss in mice. After just three days of allowing the animals to sleep for only 3-5 hours a night, they found the mice had lost 25% of the brain cells in a portion of the brain stem. This means that the idea of “catching up on sleep” may be futile and pointless.
Clean Out Junk
A research article done in the popular magazine Science noticed that sleep seems to clean out the junk within the brains of mice helping to prevent toxic build up. This “junk” referred to includes things like pieces of proteins that can cause Alzheimer’s disease as well as potentially toxic buildup that occurs when the mice are awake.
The brain literally gets washed out at night when sleep overtakes the body. The experiment showed that certain brain cells called glial cells would swell and shrink to control fluid flow within the brain. When the mice were awake, the glial cells would expand, reducing the space between brain cells and blocking the ability for fluid to flow. But when the mice were asleep, the cells contract and that fluid was able to flow again, washing out the potential for Alzheimers and other similar diseases.
Brain Imaging Scans
One study took a look at the parts of the brain that were being used in both sleep deprived and non-sleep deprived test subjects. They used brain imaging technology to discover what sleep deprivation can do to the brain during different scenarios.
The temporal lobe of the cerebral cortex is associated with the processing of language. Subjects were given verbal learning tests, and through these tests it was seen that those who were fully rested had very active temporal lobes, while the sleep deprived had little to no activity within this region of the brain. This lack of activity could also be seen in person through slurred speech.
Subjects were also given math problems to solve; normally the parietal lobes of the brain are the portion at work when one does a math problem. However, in the sleep deprived there was no activity visible in this area of the brain, unlike their rested counterparts whose parietal lobes were fast at work. The sleep deprived individuals were still able to do the problems, they were just slower and less accurate than their counterparts. This data implies that a different region of the brain already in use was used to also complete the math tasks.
The frontal lobe of the brain is generally used for speech and novel ideas or creative thinking. The sleep deprived subjects had difficulty thinking of imaginative words or ideas, oftentimes they were very repetitious and came up with cliche phrases.
Lastly, it was found that the sleep deprived test subjects had difficulty reacting well to unpredicted circumstances. They didn’t have the speed or creativity to cope with quick, logical decisions.
How Much Sleep is Needed
So how much sleep should you get to ensure these things don’t happen to you? Sleep needs are fairly individual and it’s important to learn your own body and decipher what works best for you. But on a general scale this is what your average sleep needs look like:
School Aged Children (10-11)