Sleep and the Brain

By: Lucy Cao

For years, scientists have tried to map out our brains, a mass of unparalleled thinking power, superior to that of any other animal. By definition, it is the center of the human nervous system and it is essential to our very survival. Its complicated structure has bamboozled scientists for centuries; one small alteration could mean the difference between life and death. Even a little shift in the amount of oxygen or pressure could leave a person seriously brain damaged. But how could something so vital to our well-being be so fragile? Are we unintentionally hurting the only thing that is keeping us alive?

In the 21st century, our understanding of the brain has increased significantly, yet we are still miles away from knowing why the brain is so severely affected by sleep deprivation. J. Christian Gillin, M.D., a professor of psychiatry at the University of California, San Diego (UCSD), admits that we have gone very far in mapping out the functions of the brain, but we do not know how to improve or enhance its performance. He says that “perhaps [someday] we will be able to devise interventions to alleviate the behavioural impairments associated with lack of sleep.” Every animal sleeps, but why the brain needs sleep remains a mystery.

Sleep deprivation is a commonplace occurrence in modern day culture. Every day there seems to be twice as much work and half as much time to complete it in, and truthfully, the lack of sleep affects most people in significant ways whether they know it or not. While people in different age groups require different amounts of sleep, everyone, whether young or old, needs some shut-eye; human beings cannot survive on willpower alone. The belief that people can train their bodies to not require as much sleep as they once did before is false. Rest is essential to the regeneration of one’s body, and the brain, like all other muscles in the body, needs it in order to function properly. The effects of sleep deprivation on behaviour have been tested with relation to the presence of activity in different sections of the cerebral cortex.

A team of researchers at the UCSD School of Medicine used fMRI (functional magnetic resonance imaging) technology to monitor the activity in the brains of a few sleep-deprived subjects. The researchers were surprised to find that there was a direct correlation between the activity displayed in the prefrontal cortex (PFC) of the brain and the sleepiness of the subject. They found that the sleepier the subject was, the more activity was observed in the PFC. Additionally, a brain region called the temporal lobe was activated only by well rested subjects when they participated in verbal learning exercises. However this region, which is responsible for language processing,was not activated in sleep deprived subjects. The effects of this inactivity can be observed by the slurred speech in subjects who have gone for prolonged periods with no sleep.

In a previous study that was also led by Gillin and his team of researchers, the team studied sleep-deprived subjects performing an arithmetic task involving subtraction. Similar to the results of the previous study, the fMRI scans showed that the rested subjects activated a certain part of their brain that the sleep-deprived subjects did not. Altogether, the sleep-deprived subjects had fewer correct answers and had omitted more questions compared to the well rested subjects.

One can argue that sleep deprivation is a great part of a high school student’s life. With a life composed mainly of homework, tests, assignments, and exams, us NT students are bound to be stressed and sleep deprived. In a survey of 30 students, 80% of them report to have pulled off all-nighters. And 96% of those people agree that these all nighters have affected the way they behave and think the next day. This effectively proves that sleep-loss affects learning and memory. When preparing for challenges such as exams and tests, sleep could prove to be a valuable part of a study strategy. Studies have shown that animals and humans who are deprived of sleep do not perform well on memory tasks. According to Michael P. Stryker, Ph.D., researcher at the University of California, San Francisco, sleep “provokes slightly more plasticity (connections between nerve cells) than double the amount of exposure to experience.” This means that a student would achieve the same amount of plasticity (or “learning”) reviewing her notes thoroughly and then slept compared to if she had just pulled and all-nighter reviewing her material.

One study even suggests that sleep deprivation is just as bad as alcohol impairment. In a study published by the British Journal of Occupational and Environmental Medicine, researchers in Australia and New Zealand found that sleep deprivation can have some of the same hazardous effects as being drunk. The study found that people who drove after being awake for 17 to 19 hours performed worse than those with a blood alcohol level of .05 percent.

By studying the correlation between the effects of sleep deprivation of the brain and behaviour, it allows us to observe how a person’s behaviour changes as the brain shuts down. The brain is like a muscle; while it needs to be exercised, it also needs rest. Similar to the way a person cannot jog continuously for three days, the brain cannot operate without breaks. While tired or stressed out muscles will result in restriction of movement, a tired brain will use its only defence which is to shut down the whole body. Without sleep, our brains deteriorate, and our behaviour will also suffer accordingly.