Sleep Deprivation

While growing up, many of us constantly hear a lot of urban legends. Gum will stay in your digestive system for seven years if you happen to swallow it; birds will explode if you feed them rice; if you go into a bathroom late at night, turn off the lights, and say “Bloody Mary”… I’ll leave it at that. Point is, we’ve all been exposed to many such widely believed superstitions and not all of them are true. Although not exactly the most exciting thing, something that you always used to hear from your parents during your childhood is the importance of sleep.

But just how important is sleep? How much sleep do I actually need? What are the effects of sleep deprivation? Are they serious or just wildly exaggerated to scare children? What are its symptoms? The list goes on and on. In this article, I will attempt to clear up any confusion regarding sleep, its functions, importance, and effects (or rather, effects of a lack of sleep).

Why is sleep important? The answer is quite simple: the time you spend awake is dictated by the time you spend sleeping, and your dwelling hours are indeed massively affected by it. Your brain depends on sleep to repair it overnight, preparing it for the next day, and without sleep, everything would go to hell.

Learning is another important cognitive function for which sleep is a vital factor. Whether it’s learning a new math lesson, how to play the saxophone, remembering steps to a specific procedure, or the rules of commas, your sleep plays an important role in retaining, remembering, and effectively utilizing information [1].

Next of all, you must understand the process that leads us to sleep. In other words, what makes us sleep?  Well, we all have something called a  circadian rhythm, which is the brain’s natural timer that keeps track of the time of the day, when to wake up, when to sleep, when you feel sleepy and so on. Moreover, two separate systems each work to control our circadian rhythms.

The first of which is a phenomenon called “sleep pressure.” Adenosine is a compound that accumulates in your brain while you are awake and going about your daily life. By the end of the day, a fair bit of adenosine will have accumulated in your brain, and since it’s nothing but an unwanted side product, your brain will want to get rid of it as soon as possible. Conveniently, this substance also happens to only be broken down and disposed of during shut eye, and there you have it! That’s your brain’s first system neatly summarized.

The second one is an interactive system where the brain depends on environmental signals, mainly light, to determine whether or not to release melatonin and how much of it. Melatonin is a compound that is produced by the pineal gland to signal that you are sleepy and thus makes you drowsy [2].

Now to get into my real findings. As expected, sleep deprivation has plenty of possible effects, with all of them ranging from minor to life-threatening. For example, a study [3] has shown that a chronic sleep can make you more sensitive to pain. As Dr. Aaron Carroll, MD, MS, Professor of Pediatrics and Associate Dean for Research Mentoring at Indiana University School of Medicine, paraphrased, “…volunteers were randomized to normal sleep habits or extended sleep. They then measured pain sensitivity. They also found that extended sleep was associated with reduced levels of pain sensitivity.” Another study [4] showed that sleep deprivation is associated with having lower emotional intelligence. Twenty six participants were tested, and it was found that those who were sleep deprived scored considerably lower on the tests, displaying a lesser ability to show empathy and to be assertive. A Korean study [5] touched on a matter that is rather important to us as students. It pointed out that out of 100 students, those who slept insufficiently had much worse academic performance. The takeaway is simple: a lack of sleep will very likely cause you to be a lower achiever!

Now onto one of the lethal consequences of sleep deprivation. You might find it hard to believe that alcohol is comparable to a lack of sleep! There are over 250,000 vehicular accidents caused by sleep reported each year [6]. Shockingly, The American Academy of Sleep Medicine stated that over 80,000 people fall asleep while driving every single day in the United States. Knowing that even a second of oversight can cause a lethal accident, I find that to be an absolutely terrifying statistic.

In addition, a comprehensive study authored by William D.S. Killgore, titled “Effects of sleep deprivation on cognition,” [7] provides some more examples on what sleep deprivation does to us. Citing another experiment, the study stated that in a simple hand-eye coordination test, different levels of sleep deprivation can be linked to different levels of alcohol intoxication. It says:

                A particularly compelling and practically relevant account of the decline in vigilance and attention was demonstrated by a simple but elegant study that equated hours of wakefulness with blood alcohol concentration during a visual-motor tracking task (Dawson and Reid, 1997). In that study, performance on a simple test of hand–eye tracking and coordination worsened in a linear manner during a 28-h period of overnight sleep deprivation. Moreover, performances during sleep deprivation were statistically equated with those of the same subjects at various blood alcohol concentration levels manipulated and measured on a different day. Findings showed that after 10 hours of continuous wakefulness, each additional hour awake was equivalent to an increase of 0.004% blood alcohol concentration until about 26 hours of wakefulness. In practical terms, by 17-h of wakefulness performance was equivalent to a blood alcohol concentration of 0.05%, while 24 hours awake was roughly equivalent to performance at 0.10%, a level meeting or exceeding the legal limit for intoxication in all states in the United States. The implications are clear – on average, a person who has gone for even one single night without sleep is about as impaired on early morning hand–eye coordination as an individual drinking alcohol to the legal limit of intoxication.

It should be noted that this aligns with the driving example mentioned earlier: a sleepy driver is as bad, if not worse, than a drunk driver.

Under the section “Individual Differences,” the variableness of each person’s capability to cope with sleep depression was discussed. It is common sense that all people are created differently, and that remains true when it comes to each person’s ability to tolerate sleep deprivation. It was also pointed out that each individual exhibits the same resistance throughout different episodes of sleep deprivation, showcasing the innate nature of each person’s abilities and how they are locally constant. Also under the same section was a part that speaks about something that does change within each individual: age.

The tests showed that younger adults have a tendency to be less resistant to the effects of sleep deprivation, exhibiting slower reaction times and unintentional sleep episodes. On the other hand, adults are generally less impaired than younger people after a full night without sleep, in spite of the fact that the numbers show that the adults had recorded a slightly slower reaction time.

Next come the emotional effects. Are you an optimist? Well then, you better make sure you sleep well, because two sleepless nights is linked with lowered levels of positive thinking and willingness to solve problems. In addition, the tendency to lean to unproductive strategies and “superstitious” and “magical” thinking processes saw an increase. To conclude, Mr. Killgore wrote:

                Moreover, total scores on an emotional intelligence scale declined as a function of sleep deprivation, particularly with regard to ratings of self-esteem, empathy toward others, understanding of interpersonal dynamics, impulse control, and the ability to delay gratification (Killgore et al., 2007a). Thus, sleep-deprived individuals appear to be more easily frustrated, intolerant, unforgiving, less caring, and more self-focused than when fully rested.

And last but definitely not least from this study, extreme cases of sleep deprivation (56 hours) have been shown to increase the levels of depression, paranoia, and anxiety so much to the point that the increase was classified as “clinically significant” for 1/4th of the participants. Another 17% of them reached the clinically significant level for anxiety, mania, and borderline features.

In a nutshell, sleep is crucial. You all already know that; however, you now know why it’s important, and this is a helpful step. Knowing its importance, benefits, and utter necessity, you can be conscious of what you do with your sleep. In brief, no more studying late at night!

 

References:

  1. “Why Is Sleep Important?” – NHLBI, NIH. 22 Feb. 2012. Web. 05 Apr. 2016.
  2. “What Makes You Sleep?” – NHLBI, NIH. N.p., 22 Feb. 2012. Web. 05 Apr. 2016.
  3. “Result Filters.” National Center for Biotechnology Information. U.S. National Library of Medicine, 1 Dec. 2012. Web. 05 Apr. 2016. (http://www.ncbi.nlm.nih.gov/pubmed/23204609)
  4. “Result Filters.” National Center for Biotechnology Information. U.S. National Library of Medicine, 9 July 2008. Web. 05 Apr. 2016. (http://www.ncbi.nlm.nih.gov/pubmed/17765011)
  5. “Result Filters.” National Center for Biotechnology Information. U.S. National Library of Medicine, 15 Jan. 2015. Web. 05 Apr. 2016. (http://www.ncbi.nlm.nih.gov/pubmed/25515277)
  6. American Academy of Sleep Medicine (http://www.aasmnet.org/Resources/FactSheets/DrowsyDriving.pdf)
  7. Killgore, William D.S. “Effects of Sleep Deprivation on Cognition.” Progress in Brain Research (2010): 105-29. Web.

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