Voluntary Sleep Deprivation: A Self Induced Cognitive Impairment

Introduction

It might interest you to know that humans spend one third of their lives sleeping. But in today's world, it's quite easier for a cattle to pass through a needle than for an average human to prioritize a good night sleep. Unfortunately, voluntary sleep deprivation is an offense committed by both the learned and the unlearned. 'Voluntary' in this context means that the individual involved intentionally stays awake despite feeling drowsy.

However, though career driven personalities, students, and administrators have tangible reasons (such as important business deals, all-night study sessions, etc) for depriving themselves of quality sleep. The fact is that, these reasons are not capable of excepting one from the impending consequences of sleep deprivation.

Is that project worth your sleep?

Personally, I believe that humans are rational beings and must always weigh options. Based on several scientific researches, though sleep deprivation does not cause direct death (in humans), nevertheless, the effects could help fasten the process.

According to the National Sleep Foundation (NSF), sleep, along with diet and exercise constitute the very foundation of good health. Inasmuch as this may sound like a lazy man's post (I'm lazy sha), however, it is pertinent to say that sleep is as important as food to man.

Just like several parts of the body are affected during starvation, sleep deprivation also hampers most of the biochemical and physiological processes that takes place in the body.

Most people believe that the only effect of sleep deprivation is basically daytime fatigue. However, this physical outcome is just a tip of the iceberg. Numerous cellular reactions and processes are affected by a single sleepless night resulting in really catastrophic outcome.

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Effect on the Brain

When considering the proper functioning of the human body, the brain is always the central unit. Once anything tampers with the brain, integration and coordination of information functions are similarly affected.

The region of the brain called the prefrontal cortex that is responsible for memory and reasoning is seriously affected after a sleepless night. This is the reason why sleep deprived persons take extra time to complete a simple task. Hence, suggesting a decrease in brain activity.

Aside from decreased in brain activity, sleep deprivation disconnects the prefrontal cortex from the amygdala. It is worthy of note that the amygdala is the emotional control centre, and by staying connected with the prefrontal cortex, emotional responses can be regulated. However, once sleep deprivation triggers disconnection of these two brain areas, what happen is irrational emotional responses. Individuals are seen overreacting to very minor issues or situations.

The next area of the brain affected by sleep deprivation is the hippocampus. It is the brain region responsible for storage of new memories. Just a single sleepless night drastically decreases the ability of hippocampus in memorizing new information. Hence, one must sleep so that old memories can be transferred to other parts of the brain.

According to Centre for Disease Control (CDC) the scary way sleep deprivation affects the brain is that brain neurons are dampened. This means that instead for the brain cells to carry out rapid reactions, they are weak and slow. In this case, certain portions of the brain are asleep while others are awake. Most of the accidents occur as a result of the inability of the brain neurons to function properly.

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A, Represents a normal sleep histogram with time spent in Stages N1, N2, and N3 and increasing REM (R) sleep through the night. B, Represents an abnormal sleep histogram with sleep primarily restricted to Stage N1 and scattered irregular periods of REM sleep.

Effect on The Eyes

Since most people actually do not get enough sleep these days, then I also need to educate you on the predicament you're putting your eyes through.

Staying awake all night long most times may be seen as a feat worthy of celebration, especially in situations where the tasks at hand were successfully completed. However, since all natural phenomenon have principles governing them; not sleeping when one should inevitably interfere with the biochemistry of sleep. Hence, since sight is a function of the eye, it is directly affected in the process.

The Biochemistry of Sleep

The human eye is triggered basically by respond to external light. This is why people find it much easier to stay awake in the day than in the night. According to Kristin Harper in the article "The Science of Sleep", the human body release chemicals in a 24-hour cycle, nudging the body to do certain activities at different times. One of the most important chemicals released is melatonin.

From research, the release of the hormone melatonin from the pineal gland is found to be the reason why people feel sleepy. The most important thing about melatonin secretion is that it is controlled by the level of light signals reaching the area of the brain called suprachiasmatic nucleus.

In the day, light signals from the retina are passed to the suprachiasmatic nucleus. Once the suprachiasmatic nucleus is activated by the light, it stops the pineal gland from releasing melatonin. This is why people are able to stay awake in the day. Nevertheless, towards the evening when darkness sets in, the suprachiasmatic nucleus is gradually deactivated leading to release of melatonin. The amount of melatonin secretion increases depending on intensity of the darkness. This really explain why people get more drowsy late at night.

How is melatonin synthesized?

Actually what happens is that the pineal gland absorbs tryptophan from the bloodstream. Tryptophan is one of the α-amino acids used in making proteins. Tryptophan is grouped under essential amino acids, meaning that it can only be derived from diets.

Melatonin is thereby synthesized from this particular amino acid in a 4-step reaction:

The first step is the conversion of tryptophan to 5-hydroxytryptophan by the enzyme tryptophan hydroxylase.

The second step is the conversion of 5-hydroxytryptophan to serotonin by the enzyme aromatic amino acid decarboxylase.

The third step is the conversion of serotonin to N-acetylserotonin by the enzyme serotonin-N-acetyltransferase (SNAT)

The fourth step is the conversion of N-acetylserotonin to melatonin by the enzyme hydroxyindole-O methyltransferase

Though all the reaction steps are crucial, however, the third step is the most important step when considering the biochemistry of sleep. In the day, light inhibits the enzyme serotonin-N-acetylyransferase (SNAT). Once SNAT is inhibited, melatonin can not be synthesized, hence individuals are able to stay awake. However, SNAT is very active in the dark leading to production of melatonin that makes one feel drowsy.

Effect of Sleep Deprivation on The Eye Sight

As earlier stated, melatonin synthesis determining enzyme (SNAT) can only be active in the dark. It is worthy of note that artificial light in the night alters the normal functioning of this enzyme thereby making individuals to be able to stay awake.

The presence of light leads to the enzyme degradation and inactivation. This explains why people are able to stay awake at night while watching TV, chatting with phone, working on computers, etc. Inasmuch as it feels great to be able to stay awake all night. The action of the enzyme SNAT is altered in the process.

According to the Centre for disease control (CDC), an healthy sleep range is between 7-9 hours. Sleeping less than 5 hours will keep the enzyme SNAT active the next day, leading to secretion of melatonin. This is why people feel drowsy in the day.

Aside from finding it difficult to keep the eyes open the next day, sleep deprivation causes eye spasms, a condition that results in twitching of the eye. In rare cases, sleep deprivation over a long period could lead to loss of vision due to inflammation of the blood vessels in the eye (disease condition known as anterior ischemic optic neuropathy).

Summary

From research statistics, aside from alcoholism, the increase rate of accident is as a result of the inability of sleep deprived drivers to stay awake while driving. Just as sleep deprivation effects are very fatal to the brain; individuals practicing voluntary sleep deprivation are indirectly destroying their sight and also endangering their lives.

In my next post, we'll be considering the effects of voluntary sleep deprivation on metabolism of food. To all of you that read to this point, thank you. I hope you found this enlightening?. Till next time. Sleep well, stay healthy.

The idea of sleeping extra hours on weekends as replacement for the lost sleep during the busy working days is completely illogical because, daily sleep deprivation also have its resultant daily negative effects on the human brain. Unfortunately, these effects can be very fatal in most cases.

Reference

Sleep Physiology