An Overview of Sleep

Aliya Masihuddin, Jenna Fiorentino, David Agbato (Group 5)

Department of English: The City College of New York 

ENGL 21003: Writing for the Sciences 

Professor Anna Voisard

April 5, 2020 

Abstract

Through the analysis of various sleep studies, the following dissertation outlines the different aspects of dreams and the subconscious as well as the effects that sleep has on our overall health. The paper begins by explaining sleep in general, then moves on to describing why we need sleep and how sleep improves our memory and function. The literature review then goes into depth about dreams. It discusses the different types of sleep, along with dream theories and how our dreams are influenced by our subconscious. Furthermore, the study then analyzes sleep deprivation and its effects on our health. Altogether, this research suggests the importance of sleep and how it is greatly influenced by our conscious minds. 

Keywords: Sleep, memory, dreams, subconscious, nightmares, lucid dreaming, sleep deprivation, benefits of sleep 

Introduction

Sleep is known as a “recurring state of mind and body” signified by the “absence of wakefulness and loss of consciousness”. There are four stages of sleep: NREM Stage 1, 2, and 3, and REM sleep. The first stage of sleeping is commonly known as falling asleep, and only lasts five to ten minutes as the body slows down. The next stage is when the body temperature decreases and heart beat slows, and sleep spindles begin occurring. Sleep spindles is when the “brain begins to produce bursts of rapid, rhythmic brain wave activity” (Cherry, 2019). Stage three is the phase where the body begins transitioning from light sleep into deep sleep by muscle relaxation and a drop in breathing and blood pressure. The final stage is REM where our brain and body systems become active, and dreams can occur. Although there have been countless studies conducted on sleep, it is still a vastly unknown field of study, and sleep scientists continue to study what happens while we sleep. While previous studies have shown that sleep is necessary for the body, there are many negative effects that a lack of sleep can cause. 

Background of the Necessity of Sleep

Through studies of ecology and evolution, researchers have found that although sleeping patterns vary from time period and type of mammalian, sleep has remained a necessary aspect of life. When hominins evolved to begin walking upright, they abandoned their arboreal sleeping patterns and began sleeping on flat ground. Once that occurred, they experienced a drastic increase in the amount of time they slept due to “insulation for warmth” and “a stable and secure environment to enable higher quality of sleep” (Nunn, 2016). The amount of sleep that humans were able to have depended on the dangers of the environment that they were in, and that still affects many communities today whether they are impoverished or homeless. The amount of sleep varies based on social and economic determinants, but the patterns for sleep throughout the stages of life remain the same. The pattern is that newborns sleep the most and sleep decreases as humans age. The reasoning behind this pattern is due to the fact that newborns sleep for a majority of the day, adolescents will fall asleep at later times at night, and elderly people utilize medications to help them sleep.  In a study on sleep-related car accidents, it was found that more than half of the accidents “occur in drivers under age 30, compared to only 5% in drivers over age 65” (Best, 2016). Despite the variables of age or social / economic determinants, the basic need for sleep will always be constant.

Dreaming and the Subconscious

Dreaming is an important part of our sleep. Numerous psychoanalysts and researchers have theorized and disagreed on the reason why we dream. One researcher who did extensive research on the topic of dreams was Sigmund Freud. Freud was a neurologist who founded psychoanalysis. Through this system, he extensively theorized about the human mind, and how certain actions are influenced by both our conscious and subconscious. One of Sigmund Freud’s main psychoanalytic theories was the interpretation of dreams. Three major concepts of his dream theory were the id, ego, and superego. The id is the part of one’s mind that unconsciously seeks instant satisfaction through instincts and urges. The superego is the preconscious part of one’s mind where decisions are based on ideals and morals. The ego is the part of one’s mind that mediates between the id and superego (Teusch, 2015). Freud used these concepts to fuel his Wish Fulfillment Theory. He claimed that dreams are therefore a way to reveal any subconscious thoughts. Upon studying his patients, Freud concluded that many of their thoughts came from events concealed in their subconscious since childhood. These subconscious thoughts are then revealed through dreams. Through his Wish Fulfillment Theory, Freud explained that dreams allow people to satisfy their sexual and aggressive desires in their unconscious state. Our wishes are supposedly the basis of every one of our dreams, though these wishes remain repressed since we usually forget our dreams once we wake up (Domhoff, 2019). Freud’s theory was also supported by the role of dopamine. He theorized that dopamine, a neurotransmitter that is assumed to be the “primary neurochemical active during REM sleep”, increases desires (Domhoff, 2019).

However, many researchers and theorists have rejected Freud’s interpretation of dreams. Extensive research has been done into Freud’s dream theories, with an abundance proving them to be incorrect. One theory that opposed Freud’s outdated interpretation of dreams was the activation-synthesis theory. The hypothesis was first theorized by Harvard psychiatrists J. Allan Hobson and Robert McCarley in 1975. The theory proposes that during REM sleep, dreaming is brought about by random neural activity that arises from the brain stem. The cerebral cortex of the brain creates intense cognitive activity, which causes the plot of a dream. The theory also focuses on random events that are unique to dreams. The plot of such dreams is caused by “chaotic cerebral activation processes”, leading to “visuomotor hallucinations, delusional beliefs, thought impairments, emotional storms, and memory defects” (Domhoff, 2019). With this, while Freud’s interpretation of dreams states that dreams are caused by our repressed urges and desires, the activation-synthesis hypothesis opposes it by theorizing that dreams are caused by intense neural activity that causes various visual imagery. While the debate over why we dream has continued to the present day, modern-day psychologists have seemed to move away from Freud’s theories of dreams.

Types of Dreams

One type of dream that is heavily influenced by conscious actions and feelings is nightmares. Nightmares are dreams that occur during REM sleep that contain dysphoric feelings (De Macêdo, 2019). They are often described as being very distressful, involving frightening and threatening subjects. Nightmares are usually caused by conscious factors, such as stress and anxiety, that influence the unconscious mind. They can either be spontaneous or recurring. On the other hand, lucid dreams, another type of dream, usually have a more positive effect. Through lucid dreams, dreamers are aware that they are currently dreaming. They are able to take control over the contents and their actions in their dream. Interestingly enough, researchers have done experiments to find out if lucid dreams can actually manage nightmares. Some research has shown that lucid dreams can minimize nightmare frequency, intensity, and psychological distress (De Macêdo, 2019). One reason for this is due to the ability to control dreams. When one is having a nightmare, it may be possible to regulate the contents of the dream, thus treating the effects of the nightmare. However, research found that out of ten patients that used lucid dreaming as a therapeutic approach to nightmares, only five of them reported beneficial effects from the lucid dream (De Macêdo, 2019). Therefore while dreams containing scary or threatening images/visuals cannot easily be suppressed, it is possible for lucid dreams to provide positive results.

Sleep Deprivation 

A direct result of these anxiety inducing dreams known as nightmares is sleep deprivation. This commonly experienced phenomenon known as sleep deprivation is typically characterized by continuously acquiring under seven hours of sleep per night. With the average recommendation of sleep for adults ranging between seven to eight hours a night, a regular deficiency can accumulate into a substantial sleep debt, which is defined as total sleep lost. This significant lack of sleep can cause an array of detriments to the human body in both a mental and physical sense. While sleep deprivation can be experienced universally, one of the most prevalent populations facing this struggle includes adults, particularly those entering high pressure occupations in the medical field. 

Among the substantial deficiencies caused by a lack of sleep are physical drawbacks to one’s overall health. According to the National Heart, Lung, and Blood Institute, sleep aids in the healing and repair of the heart and blood vessels thus, “Ongoing sleep deficiency is linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes, and stroke” (NIH). The severity of these afflictions directly demonstrates the vast damage that sleep deprivation can cause an individual and the lifelong consequences associated with this condition. Alongside these risks, insufficient sleep is also associated with higher instances of obesity. In a study based on the National Health and Nutrition Examination Survey from 2015 to 2016, researchers found that, “Participants who slept less than 7 h were 1.83 times more likely to be overweight and 1.57 times more likely to be obese than participants who sleep 7 to 9 h” (Li, 2021). As demonstrated, there is a direct correlation between sleep deprivation and obesity as well as sleep deprivation and being overweight. This correlation is thoroughly understood as sleep aids in the maintenance of the body’s hormones such as ghrelin (a hunger inducing hormone) and leptin (a hunger suppressing hormone). When there is a substantial sleep deficiency, the levels of ghrelin are known to increase, thus justifying the relationship between sleep deprivation and weight gain leading to obesity. Furthermore, the familiarity that certain individuals including healthcare workers have with this condition have allowed additional hindrances to be observed such as weakened immune systems allowing for the onset of various illnesses and the well known obstacle known as fatigue. 

In addition to the physical demands of an occupation within healthcare, the mental toll that these positions can take coupled with sleep deprivation is alarmingly unhealthy. In a study conducted on health care professionals that were rotational night shift workers, “the presence of cognitive impairment was noted in 34.8% of the participants” (Nirupama, 2021). Thus, a relationship between cognitive impairment and sleep deprivation can be seen. Likewise, the study also takes note of how sleep deprivation is associated with “disturbances in cognitive and psychomotor function including mood, thinking, concentration, memory, learning, vigilance, and reaction times” (Nirupama, 2021). The deterrence of these essential skills leaves room for error, which is extremely dangerous in the field of healthcare. Furthermore, as aspiring healthcare workers, medical students face similar mental drawbacks from this lack of sleep. For instance, in a study conducted with 22 medical schools, researchers found that “Medical students that presented higher daily sleepiness scores (ESS) showed lower perception of educational environment” (Perotta, 2021). This statistic conveys the distressing message that insufficient sleep can greatly inhibit learning and retention in students. Additionally, this study revealed that higher daytime sleepiness scores were also associated with higher occurrences of depression and anxiety symptoms. Hence, these research articles strategically utilized the population of sleep deprived medical students and healthcare workers to illustrate the harmful effects of sleep deprivation on both the cognitive abilities and overall mental health of these individuals. 

How sleep improves memory / function

Although sleep deprivation has been proven to cause serious physical and mental effects on the body,  the positive effects that sleep has on memory and function have also been studied and analyzed. The most important aspect of sleep is that it is the only opportunity that the brain has to heal, restore nutrients and remove toxic substances. The brain uses 20% of the energy that is stored in our body to function properly, and while we sleep the brain restores “essential nutrients (like glycogen)” that we use as our energy source (Best, 2016). Additional studies have shown that sleep significantly improves memory and health. In a study of forty adolescents of the ages of ten to fourteen, the subjects were separated into two groups of those who got sufficient sleep and those who got no sleep. Each group was given the same testing sessions and presented with the same material for a memory test. The results from the experiment showed that “an increase of 20.6% in long-term memory was found as measured by the number correct in the paired-associate test following sleep, compared to the group which was tested at the same time interval, but without sleep” (Potkin, 2012). From the study, it was understood that adolescents who obtain enough sleep will demonstrate long-term memory skills which can affect their ability to retain information in school. During sleep, the body also removes dangerous substances from the brain such as beta-amyloid protein that has been proven to cause Alzheimer’s disease, a disease that causes memory loss. In addition to improving memory, the rest of our body depends on sleep to be able to repair and restore their system. Our body is connected to an internal cycle that allows our functions to align with behavioral and physiological activities such as eating, cell reproduction, body temperature, waking up, and homeostasis. Without sufficient sleep, it can cause “the inability to fall asleep or stay asleep, excessive daytime sleepiness, chronic fatigue, increased pain perception, and randomly falling asleep at unusual times” (Brady, 2017). When we interrupt our sleeping patterns by staying up too late or waking up too early, it can disrupt our bodies’ restoration of cells and damage our health, resulting in long time effects on our body. 

Conclusion 

The complexity of sleep and its extensive nature allows ongoing research to prove the multitude of ways in which sleep influences our everyday lives. Despite understanding certain topics such as the benefits associated with sleep versus the detriments associated with the lack of sleep, there is still a large gap of knowledge that scientists don’t yet know about this topic. From the aforementioned theories of why we dream during sleep to understanding the deceptively simple question of why we sleep, modern science has a long way to go to before being able to provide thorough answers. All in all, acknowledgment of the various subtopics associated with sleep allows individuals to understand its vast importance as well as the way in which it impacts various aspects of our lives. 

Works Cited

Best, B. (2016, August). Sleep medicine conference. Life Extension. 

https://link.gale.com/apps/doc/A466297224/AONE?u=cuny_ccny&sid=AONE&xid=cdd

7486f

Brady, D. M. (2017). Sleep Quality as a Major Factor in Fibromyalgia and Chronic Pain and 

Fatigue Disorders. Townsend Letter, (412), 38+. 

https://link.gale.com/apps/doc/A512184948/AONE?u=cuny_ccny&sid=AONE&xid=4c140164

Cherry, K. (2019, October 31). The 4 Stages of Sleep (NREM and REM Sleep Cycles). Verywell 

Health. https://www.verywellhealth.com/the-four-stages-of-sleep-2795920

De Macêdo, T., Ferreira, G., De Almondes, K., Kirov, R., & Mota-Rolim, S. (2019, November 

06). My dream, my rules: Can lucid dreaming treat nightmares? Retrieved March 22, 

2021, from https://www.frontiersin.org/articles/10.3389/fpsyg.2019.02618/full

Domhoff, G. (2019). Database menu. Retrieved March 22, 2021, from 

http://ccny-proxy1.libr.ccny.cuny.edu/login?url=https%3A%2F%2Fsearch.ebscohost.com

%2Flogin.aspx%3Fdirect&db=pdh&AN=2019-78466-001&site=ehost-live

Li, Q. (2021). The association between sleep duration and excess body weight of the American adult population: a cross-sectional study of the national health and nutrition examination survey 2015-2016. BMC Public Health, 21(1). https://link.gale.com/apps/doc/A653583780/AONE?u=cuny_ccny&sid=AONE&xid=8707c62d

Nirupama, A., Chellaiyan, D., & Ravivarman, G. (2021). Are rotational night shifts taking its toll on health-care professionals? A pilot study. Current Medical Issues, 19(1), 19. https://link.gale.com/apps/doc/A649095100/AONE?u=cuny_ccny&sid=AONE&xid=55b00295

Nunn, C. L., Samson, D. R., & Krystal, A. D. (2016). Shining evolutionary light on human sleep 

and sleep disorders. Evolution, Medicine, and Public Health, 227+. 

https://link.gale.com/apps/doc/A484312982/AONE?u=cuny_ccny&sid=AONE&xid=3beafacb

Perotta, B., Arantes-Costa, F. M., Enns, S. C., Figueiro-Filho, E. A., Paro, H., Santos, I. S., Lorenzi-Filho, G., Martins, M. A., & Tempski, P. Z. (2021). Sleepiness, sleep deprivation, quality of life, mental symptoms and perception of academic environment in medical students. BMC Medical Education, 21(1). https://link.gale.com/apps/doc/A653612780/AONE?u=cuny_ccny&sid=AONE&xid=b77df892

Potkin, K. T., & Bunney, W. E. (2012). Sleep Improves Memory: The Effect of Sleep on Long 

Term Memory in Early Adolescence. PLoS ONE, 7(8), e42191. 

https://link.gale.com/apps/doc/A543305086/AONE?u=cuny_ccny&sid=AONE&xid=e67c129e

Sleep deprivation and deficiency. (n.d.). Retrieved March 15, 2021, from https://www.nhlbi.nih.gov/health-topics/sleep-deprivation-and-deficiency

Teusch, R. K. (2015). Database menu. Retrieved March 22, 2021, from 

http://ccny-proxy1.libr.ccny.cuny.edu/login?url=https%3A%2F%2Fsearch.ebscohost.com

%2Flogin.aspx%3Fdirect&db=psyh&AN=2014-43284-001&site=ehost-live