Why Do We Sleep?

As we all know, one third of our life is spent to sleep, but very few people intend to lay bare the secret of that. There would be a question: why do we sleep? According to the video “The Function of Sleep”, Tyson states that people are not very clear about the purpose of sleep, but some researchers believe that sleep could enhance memory. MIT researcher Matthew Wilson also illustrates the thoughts of a rat can be read by implanted the electric wire into its brain. According to a special project “rat maze”, memory not only affects the rat finds the way with same pattern, but also generates the main part of its dreams. The video also concludes that the function of sleep is learning and memory, and it is not just a biological process, not matter for humans or animals (“The Function of Sleep”). Although a lot of young people claimed that sleep is not important and they could stay up all night, I have to say that lack of sleep will lead to physical, psychological and intellectual problem. To begin with, having no enough sleep is dangerous to human health.

First, people who have poor sleep frequently are more likely to suffer from heart disease, stroke and high blood pressure. According to “Lack of Sleep Linked to Heart Problems”, poor quality of sleep can raise cortisol levels, which fuels inflammation that can destabilize plaques. Once these deposits rupture, they can block vessels in the heart or brain, causing a heart attack or stroke. Besides that, sleep is an essential period for reducing blood pressure. People sleeping less will have shorter periods of lower blood pressure, thus increasing their tendency to prompt blood pressure (Park). For example, Tina, my friend in China, who often work overtime or even overnight has heart problem, although she is just 30-year old. Second, there is a direct connection between sleep quality and a person’s length of life. Getting good sleep may even increase your longevity, and vice versa. According to Dr. Michael Twery, director of the National Center on Sleep Disorders Research, a part of the human brain orchestrates hormones and other changes throughout our bodies to prepare it for sleep.

By keeping this system aligned and falling asleep when our bodies signal us to do so, we are optimizing our metabolic rates and cardiovascular systems, among other functions, within our bodies. However, if we struggle with a sleep disorder, we aren’t letting our bodies do their best work. This eventually puts us at risk for more serious illness that impacts our longevity (Daggett). For example, a study of 10,308 civil servants in Britain aged 35 to 55 over 12-year period shows that decreasing your sleep time was linked to an increased risk of death. Basically, people who sleep less than 7 hours were more likely to die over the course of the study (Stibich). Third, Insufficient sleep could lead to overweight and obesity. Studies have shown that when sleep is restricted, the hormone ghrelin increases and the hormone leptin decreases. Ghrelin tells our brain that we’re hungry, while leptin tells it we’ve eaten enough. In other words, when we don’t get enough sleep we feel hungry, even if we’ve eaten enough (Stein).

For example, in order to lose weight, my aunt has tried many ways, including keep diet and does more exercises; however, the effect is indistinct. I suppose that the main reason is lack of high-quality sleep. In a word, enough sleep is necessary to keep health. In order to enjoy high-quality life, we should foster our sleep habits as close to what our bodies biologically demand as much as possible. Moreover, insufficient sleep also has relationship with psychological problem directly. First, depression is strongly associated with shorter sleep duration. According to R. Robert Auger, a sleep specialist at the Mayo Center for Sleep Medicine in Rochester, people with insomnia and no history of depression would be four times more likely to develop depression than individuals with no history of insomnia (Mann). For example, I always feel low on energy and joyless because of having no enough sleep these days, even if I’m not an insomniac. Second, lack of sleep has a significant effect on mood. As the University of Pennsylvania researchers showed, people who were deprived of partial sleep for one week feeling more stressed, angry and mentally exhausted.

However, there would be a dramatic improvement in mood if they resumed normal sleep (Epstein). For example, I work up all night on Wednesday in order to finish my homework on time. When I came to school the next day, I felt more irritable, short-tempered, and vulnerable to stress. If you have no the similar experience, you couldn’t image how awful the personal condition after poor sleep. Third, the quality of sleep also affects self-confidence. As we know, confidence is very important to make success in social interaction among humans. However, if you are not getting enough sleep, you must believe you look terrible and make effort, which would influence your communication with others and performance in your work. For example, when I see my worn out face in the mirror in the morning after 3 or 4 hours’ sleep, I don’t like how I look. Even when I come to school, I also tend to be uncomfortable because I couldn’t present myself under the best possible condition.

All in all, physical well-being is affected by sleep patterns. Chronic sleep loss can contribute to a range of psychological problems, which is severe enough to interfere with our daily activities. In addition, intellectual problem is partly the result of lack of sleep. First, nothing makes it harder to concentrate than sleep deprivation. Nowadays, scientists and health experts have linked a lack of sleep to problems with concentration. The lack of sufficient sleep can affect your ability to carry out daily responsibilities because you are too tired to concentrate. For some students, who suffer from chronic sleep deprivation, should be not surprised to get an unsatisfactory grade in the examination. For example, I couldn’t concentrate on my English class on Wednesday, which is the result of my poor sleep on Tuesday night. Although I love English and try to listen to the teacher carefully, the tired brain was not under control. Second, long term deprivation from sleep will influence the ability of learning and memory.

A lot of animal and human studies state that the quantity and quality of sleep have a profound impact on learning and memory, for sleep has a role in the consolidation of memory, which is essential for learning new information ( Stickgold). The experience of my sister Lucia and I is a good example. During the period of preparing for the IELTS last year, Lucia usually slept nine hours a night while I got up early and went to bed late. Consequently, she got a higher grade than me, which may seems unfair, but it does bear out the advantage of sleep wonderfully. Third, sleep loss can also affect the thinking ability of the brain. According to the research, a night of sleep deprivation boosts production of brain regions that assess positive outcomes and minimizes the parts of the brain that analyzes negative outcomes. What this is means is that tired people may make riskier choices in decisions that involve avoiding loss and pursuing gain (“goerie.com”).

For example, my families often play cards on weekend, and my dad almost loses every time, even if his skill is excellent. Having no enough sleep is the most important reason for his bad performance. In conclusion, sleep does affect intelligence. Once you have some trouble to learn, memorize or make right decision, you’d better consider whether you get sufficient sleep. As mentioned above, sleep is essential to keep physical and psychological health as well as improve the cognitive ability. However, lack of sleep, which is an unavoidable part of modern life, has become a global problem. Moreover, the significance of sleep has not attracted everybody’s concern, especially young people. There is no doubt that everyone pursues longer, healthier, happier lives, which means the whole society should do something for improving the quality and duration of sleep, no matter individuals or governments.

Works Cited

Daggett , Shannon. “How Does Sleep Impact Longevity?.” life.gaiam.com. Gaiam Inc. , n.d. Web. 19 Feb 2012. Epstein, Lawrence. “Sleep and Mood.” healthysleep.med.harvard.edu. Harvard Medical School, 15 Dec 2008. Web. 19 Feb 2012. Mann, Denise. “Are You Depressed — or Just Sleepy?.” www.webmd.com. WebMD LLC., 19 Jan 2010. Web. 19 Feb 2012. “No sleep affects thinking.” goerie.com. Erie Times-News , 14 Mar 2011. Web. 19 Feb 2012. Park, Alice. “Lack of Sleep Linked to Heart Problems.” TIME.com. Time Inc. , 23 Dec 2008. Web. 19 Feb 2012. Stibich, Mark. “Sleep and Your Life Expectancy.” About.com. The New York Times Company, 30 Oct 2008. Web. 19 Feb 2012. Stein, Anne. “Lack of sleep contributing to obesity.” articles.chicagotribune.com. Tribune Newspapers, 29 Jun 2011. Web. 19 Feb 2012. Stickgold, Robert. “Sleep, Learning, and Memory.” http://healthysleep.med.harvard.edu. Harvard Medical School, 18 Dec 2007. Web. 19 Feb 2012.