Sleep Deprivation and Its Effects

Running header: Sleep deprivation
University of Buffalo (SIM)
(UB- SIM)
Sleep Deprivation and its Effects
Focusing on Effects on: Health, Performance and Cognitive Functions

Tan Jing Wen Marius
Tan Li Xuan Rayna
Tan Mei Yu
Teo Zi Wei Cheryl 16 Nov 2012
Abstract
This paper is on the effects of sleep deprivation. The central research question of this paper is: What are the effects, according to recent literature, of sleep deprivation on someone’s health, performance and cognitive functions.

Introduction
Sleep is the natural recurring state of the absence of consciousness. Sleep assists in growth and regeneration of immune, nervous, skeletal and muscular system. In short, sleep is an important factor to the health and well-being of a person. Performance errors, illnesses and traffic accidents are some of the events that have been related to the lack of sleep. Considering the importance of sleep, how does the sleep deprivation affect someone’s health, performance and cognitive functions?

Review of Literature
A total of 6 psychology journals on sleep deprivation and its effects were reviewed before the development of this paper. Swanson, Arnedt, Rosekind, Belenky, Balkin, Drake (2008) studies found that sleep deprivation affects one’s alertness as well as moods (increased anti-socialness); Geroge C. Wagner (2011) results showed that sleep deprivation affects alertness as well as performance; Gilbert, Weaver (2010) found that the lack of sleep resulted in poorer examination results; Javier Roca (2011) found that sleep deprivation reduces one’s response time and as such, sensitivity is affected; Killgore,W.D.S (2010) found out that sleep deprivation reduces one’s cognitive functioning and thus the ability to recall, alertness and sensitivity is reduced; Orzeł-Gryglewska studies showed that sleep deprivation negatively affects one’s health as well as eating habits.

Methods
A simple questionnaire of 10 questions was drawn up after the review of literature. Ten healthy young adults who have or were experiencing sleep deprivation participated in an interview to find out how the lack of sleep affected their health, performance and cognitive functions. Each of the participants was asked to respond to the questions to the best of their ability.

Results
Majority of the participants felt that the lack of sleep affected their health, performance and cognitive functions. Some of the answers were as such:
· “It harms my health and my organs. I think that there will be liver failure, or so my mother sings. But physically my skin would look tired, dull and acne, dark eye circles as well as eye bags would start to surface.”
· “I tend to notice minute things that really irritates. People chatting may appear to sound like annoying blabber of nonsense. A bus stopping while I am on it could irritate me simply from the little jerks which makes me pissed at the driver. Clicking of pens in class sound like people hammering nails into a wall.”
· “I suffer from lapses in memory, forgetting to take important items. I am unable to stay focused to complete my tasks.”

Alertness
100% of the participants felt that the lack of sleep affected their concentration in class with the incapability to pay attention to the lecturer speaking citing issues of wanting to fall asleep and presenteeism. Participants were unable to understand and internalize the material due to the lack of concentration. A study done showed similar reports of the difficulty to concentration at work with about 29% of the participants falling asleep at work or having extreme sleepiness. (Swanson, et al, 2008)

Sensitivity
50% of participants reported an increased in sensitivity. Participants stated that they would become more sensitive especially towards something that irritates them for example the sound of clicking of pens in class may sound like people hammering nails into a wall. The remaining 50% stated that sleep loss reduced their sensitivity, as they are more prone to “spacing out”. Roca’s research (2011) has proven that sensitivity will be reduced and the percentage of false alarms (error commission) increased as a result of sleep loss. In the experiment, when a warning tone had been sounded, those who had a normal sleep night responded faster. The attention score for sensitivity without sleep deprivation is 2.3 as compared to 1.9 for those who are sleep deprived.

Performance
60% of the participants reported an increased in careless mistakes as well as clumsy behaviour. Participants felt that their behaviour was due to the lack of energy which in turn prevented their body from functioning normally. However the other 40% of the participants felt that they were clumsy by nature and sleep deprivation did not play a role in this behaviour. Geroge C. Wagner’s (2011) studies shows that “sleep deprivation is associated with reduced alertness and poor performance, and these effects are exacerbated by a superimposed circadian disadvantage”.
90% of the participants felt that processed things slower which lead to inefficiency in their daily tasks. The constant lack of sleep made them lose focus and increased procrastination of a particular work, thus they need additional time to finish a seemingly easy task which they could have complete it quickly if they had enough sleep. They also felt that the lack of sleep reduced their ability to multi-task. Killgore,W.D.S (2010), found that the lack of sleep has a detrimental effect on daily activities due to poorer cognitive functioning. A sleep-deprived person has reduced vigilance level while a person with adequate number of rest has a faster reaction time and makes fewer mistakes.

Grades
60% of the participants in the current study felt that the lack of sleep affected their performance in the exams in terms of remembering the information and their final results. Participants felt that they would fail to recall the information when needed during an exam and thus lead to poor results in their exams. Gilbert, Weaver (2010)’s study also proved a similar correlation between both factors of sleep deprivation and poor results.

Moods
Almost 90% of participants reported a higher possibility of irritability, annoyance and were more temperamental after the lack of sleep. Participants also had lesser tolerance while interacting with people and were more likely to avoid social interaction. Previous studies has also showed similar results of participants with a higher degree of anti-socialness, with about 20% reporting how it negatively affected their relationships (Arnedt, et al., 2008).

Health
90% of the participants felt that their overall health had decreased due to the lack of sleep. Participants reported a decline in their body immune system as they fell sick more and experienced an in increase occurrence of headaches. Orzeł-Gryglewska’s (2010) study also found that sleep deprivation not only leads to weariness, but can also be detrimental to one’s health.

Food consumption and weight gain
20% of the participants reported an increased in food consumption as food was used to maintain their alertness. The reminding 80% reported a 10% to 60% decrease in food consumption. The participants reported a loss of appetite as sleep was their current priority and as such they did not have the mood to consume any provisions. However, 60% of participants reported an increased in weight gain. Participants felt that their metabolism slowed down due to the lack of sleep which resulted in their weight gain. 10% of the respondents reported a decline in weight due to their loss of appetite. 30% reported no changes in their weight. In her study, Orzeł-Gryglewska (2010) pointed out that a growing body evidence points out that sleep restriction leads to changes in the immune function and an increased tendency to gain weight.

Memory
90% the participants reported a decrease in their ability to recall something when they are sleep deprived. Due the lack of sleep, the participants felt that they recalled things at a slower pace. Participants stated that an adequate amount of sleep would allow them to recall information better than the lack of sleep as with adequate rest they will be in a more relaxed state and as such would be able to concentrate and focus more efficiently resulting in higher output of information. Killgore,W.D.S (2010) found that one of the effects of sleep deprivation was the significant decrease in the ability to recall.

Discussion
Our study has shown that sleep deprivation affects alertness, moods, overall health, eating habits or food consumption, and memory. According to the National Sleep Foundation, there is no “magic number” for the number of hours of sleep required. The average amount of sleep that is needed is as such.

However, this is only a guideline. The required amount of sleep required varies across population, age, and ethnic groups as well as your lifestyle, stress level and the quality of sleep (National Sleep Foundation). To understand the importance of sleep, we need to look at how and why the lack of sleep affects us.

The most immediate effect of sleep deprivation is sleepiness. Sleep deprivation will impact reaction time by causing sleepiness, with sleep bursting in as micro sleeps creating a problem with the response but in general, increasing reaction time. (Idzikowski, n.d, parg. 7)

In addition, cognitive functions such as concentration, working memory and logic reasoning are also affected by sleep deprivation as the prefrontal cortex (PFC), where critical thinking and decision- making occurs, will result in low activity. Thus, a sleep-deprived person will be unable to perform well in tasks that require high level of thoughts and reasoning. (Czeisler, 2007)

Sleep deprivation affects performance as it increases risk taking behaviours as well as the difficulty of recalling things and generating new solutions. One would also be more suggestible to what others might be saying and as such easily influenced (Idzikowski, n.d, parg. 9).

The lack of sleep also enhances negative moods as it affects the medial-prefrontal cortex which in turn increases the processing in the amygdala. The medial-prefrontal cortex (MPFC); proposed to exert an inhibitory, top-down control of amygdala function, resulting in contextually appropriate emotional responses. The lack of sleep inappropriately modulates the human emotional brain response to negative aversive stimuli and as such, the increase of negative mood and lesser capability to regulate one’s anger. This explains the various emotions like irritability and hostility that is seen in a sleep-deprived person. (Seung-Schik Yoo, Ninad Gujar, Peter Hu, Ferenc A. Jolesz and Matthew P. Walker, 2007)

In addition, a person’s immune system is made up of several types of cells and proteins to keep illnesses at bay. Sleep deprivation suppresses this immune system function and as such, your body’s ability to respond to infections decreases. For example, T-cells will go down and inflammatory cytokines increase which would lead to a higher risk of a cold and having poor fever responses which increases the possibility of a fever. (Diwakar Balachandran, n.d) A person’s reaction to vaccines also decreases due to sleep deprivation as the immune responses is suppressed and less antibodies to certain vaccines is developed. As it takes the body a longer time to react to immunizations, a sleep-deprived person will be more likely to get sick. (John Park, n.d)

A sleep deprived person is more likely to have a higher average body mass index (BMI) due the affected hormones which controls factors like our appetite and energy metabolism. Insufficient sleep tips the balance of these hormones like an increase in cortisol. Insulin also increases after eating, which regulates glucose processing and promotes fat storage and higher levels are related to weight gain. Sleep deprivation is also related to lower levels of leptin, a hormone, which alerts the brain of enough food and higher levels of ghrelin, a biochemical that stimulates appetite. Therefore, it may result in food cravings which in such lead to weight gain (Mullington, n.d).

Studies have also found that the quantity and quality of sleep affects learning and memory. This is mainly because sleep plays a major role in memory consolidation, which is essential for acquiring new information, and a sleep-deprived person has a lack of ability to focus attention optimally. Memory consolidation takes place when we are asleep, and that is when memories are formed through strengthening of the neural connections. In addition, researchers suggest that during the different stages of sleep, there might be specific characteristics of brain waves which are linked to the formation of certain types of memory. When we are sleep-deprived, our focus, concentration and attentiveness level are reduced, making it difficult for us to receive information. With the lack of sleep, neurons are overworked to coordinate information accurately; hence we are unable to recall information that was previously learned. (Stickgold, 2007)

Conclusion
Think of your body as a car. No car can keep running without a tune-up or oil change. Without proper maintenance, your car may keep running, but not as smoothly as it will run with proper maintenance. You can think of sleep as your body’s daily tune-up. Without the sufficient amount of sleep, our bodies would not be able to function at its full capacity.

References
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