Why do we sleep?

It's 12 a.m., and you've been trying to achieve a new level in a game for hours on end, when your body begins to fatigue, feeling extremely tired. Have you ever wondered why we become exhausted and sleepy during the night but wide awake during daytime? What occurs to our bodies and why is it so important to us? This essay explores why we humans sleep.

Importance of sleep 

Primarily, sleep is essential for all living organisms, without sleep your brain cannot function properly. It could also dramatically lower your quality of life. Sleeping is a required process during which your body regulates its critical systems like respiration, immune system, growth and circulation (Dr.Binocs show, 2019). However, the most vital part of our body that alters while we sleep is our brain as a fifth of our body’s circulatory blood is sent to your brain as we snooze. It enables your body to repair and freshen up for the next coming day putting you in a bright good mood with many benefits along with that. For instance, It reduces stress, strengthens your memories, increases your creativity and lowers risks for serious health problems. According to a study from Harvard, “Many Costs of poor sleep goes unnoticed. Medical conditions, such as obesity, diabetes, and cardiovascular disease, develop over long periods of time and result from a number of factors, such as genetics, poor nutrition, and lack of exercise.” (Dr. Ann E Rogers, 2008) are consequences of inefficient sleep. Better sleep may help in feeling better both emotionally and physically in general as well. Furthermore, it helps us conserve energy since we use less during our sleep. Therefore, it is important to sleep.

Sleep stages 

Sleep feels similar to a pause button, you leap onto your bed, tighten your eyes and stop functioning. Though there are masses of things going on in our body. Sleep consists of 4 stages, awake, light, deep and REM sleep. The deepest of which is known as ‘slow-wave’ sleep and ‘rapid eye movement (REM)’. In the course of stage 1 is the transit of being awake to asleep. This period lasts several minutes when your breathing, heart rate and brain activity begins to slow. Subsequently changing into stage 2 as our heartbeat, breathing and muscles relax even more; our body temperature drops and eye movement stops. Chemicals block in senses making it difficult to be woken. Throughout stage 3 our breathing and heart rate slows the most out of all stages and our muscle entirely eases when our brain wave slows even more. This is when growth hormone is released. Moreover, during the last stage, REM sleep comprises about 90 minutes after falling asleep, it revitalises the memory and is when the duration of most dreams begin as a result of high brain activity. This allows your body and mind to rest and recharge which also links to how our memories are stored.

In addition, we all have an internal biological clock that regulates our 24 hour sleep-wake cycle that we call the circadian rhythm. This clock is influenced by environmental cues such as light. Till Roenneberg, a professor of chronobiology in Munich, held a bunker experiment in 1960 on humans to pinpoint the working of  our biological clock. His test subjects had to isolate themselves in a sealed bunker without knowing when it’s day or night, observing every moment and examining and handing them tasks such as writing down what they ate. Many of them were asked to press a buzzer of what they believed to be hourly intervals and again one minute after that. Many scientists who observed the experiment concluded that "We found out that people do indeed have a biological clock that follows a circadian rhythm. You can see it in action when you remove all information about the outside world. The clock starts to take on a life of its own, shaping its own day rather than leaving us in a state of chaos. Most people's clocks, however, don't run on a tight 24-hour schedule. It's more like 25." which follows their theory. The investigation demonstrates how each of us relies on our biological clock. But the experiment soon came to an end in 1980.  When there is light during the day, your brain releases a hormone called cortisol, which keeps you awake up and going. This links together, showing that we have our own conception of time. In contrast, when the night appears causing darkness, your brain triggers the release of melatonin - a hormone that makes you sleepy. It promotes consistent, quality sleep that is beneficial to your health.

Dreams 

Dreams are also one of the foremost reasons why we have to sleep. As I have mentioned, when we enter the rapid eye movement sleep (REM) we start to dream. Though many patients do not remember dreaming it is dominant to our physical health, mental health and emotional well-being. It plays a significant role on how our memory works, while we doze off our brain is sorting and storing information from the day. This process is particularly essential for creating long term memories and clears our unwanted  information as your brain consolidates all the information it’s picked up during the day and files it for later use. 

Many biological processes - processes that are required for an organism to live - happen during sleep. Nerve cells communicate and reorganise, thus supporting healthy brain function. The body restores energy, repairs cells and releases molecules such as hormones and proteins. Hence, this implies that, if we did not get enough sleep we wouldn’t be able to recall certain information. Paul J. a psychologist who has studied sleep at Northwestern says that “Rather than learning something new in your sleep, we’re talking about enhancing an existing memory by re-activating information recently acquired.” For instance, if we’re learning a new foreign language during the day and trying to reactivate those memories during sleep, perhaps you might enrich your learning. This indicates that memory is actually strengthened for something you’ve already learned and forges new thought connections. 

But what about people who are struggling to sleep? The majority of adults need 7-9 hours of sleep per night to complete their duty optimally, just as it needs air and water to function at its best - to heal your body and restore its chemical balance and help memory retention. Yet most adults nowadays are coping with 6-7 hours of sleep which can have many long-term and short-term detrimental effects on their body. For this reason, many teenagers and adults suffer through sleep deprivation and disorders caused by consistent lack of sleep that reduces their quality and length of sleep. M Bentivoglio & G Grassi Zucconi (1997) asserts that “Marie de Manacéine, who studied sleep-deprived puppies kept in constant activity. She reported in 1894 that the complete absence of sleep was fatal in a few days, pointing out that the most severe lesions occurred in the brain.” From this experiment of Marie, they observed the degenerative changes in the dog's brain and studied insomnia and sleep deprivation further on and the similarities puppies have with us humans. This suggests, regularly getting less than 7 hours of sleep can have long-term health consequences that greatly affect your entire body. A review of studies found that sleeping too little at night increases the risk of early death. It can originate from health problems or too much stress and anxiety. Stimulants such as caffeine can indeed lead to night time insomnia and make sleep deprivation worse by making it difficult to fall asleep at night (AASM, 2018). Your central nervous system is your body's principal information highway. Sleep is crucial for your body to function correctly, but severe insomnia can cause disruptions in the way your body sends and processes information. Sleep deprivation exhausts your brain, making it unable to perform its duties efficiently. It may also be more difficult for you to concentrate or learn new information. Your body's signals may also be delayed, decreasing your coordination and raising your chances of an accident. 

On top of that, sleep deprivation has a severe impact on your mental and emotional state. You might feel more impatient with mood swings. It can also stifle creativity and decision-making processes. If this continues for a long period of time, you might start having hallucinations, which are when you see or hear things that aren't really there. 

Peter’s Tripp experiment

A sleep experiment has been set way back in 1959 when Peter Tripp - one of the most famous radio presenters during the 1950s - came up with a unique way to raise money for a children's foundation. Tripp decided to sit inside a glass booth in Times Square and broadcast his radio show for 201 hours straight. Many doctors and scientists, along with the curious general public observe him in his giant goldfish bowl. During the broadcast he appeared to be in good spirits. Nevertheless, by day 3, Tripp was cursing people around him and began hallucinating. He thought there were spiders in his shoes, for instance, and removed them to check. The observing scientists noted that his brainwave appeared to mirror what would usually be the 90 minute REM sleep cycle - the sleep stage when dreaming typically occurs (Ethan G, 2021). Consequently, during those specific periods he was seeing dream imagery whilst awake. He later then slept for 13 hours, after which he reported that he had recovered well despite struggling to hold onto reality. Tripp's family disagreed on Peter’s recovery though, claiming that he was a changed man who was still dealing with consequences of his experience and effects of the experiment. Shortly afterwards, he got divorced, lost his job and potentially became a travelling salesman. Many experiments have been conducted after that: The Chinese tortured their prisoners by not allowing them to sleep. All in all, this demonstrates that no sleep could lead to many major effects on your body both physically and emotionally so it is dominant to obtain enough sleep.  

MRI scans 

Some scientists use a non-invasive imaging technology such as the ‘dream machine’ or the Magnetic Resonance Imaging (MRI) to detect and measure brain activity while humans are sleeping.

This technology in short is used to scan through our body to investigate anatomy and function of the body in both health and disease without the use of damaging ionising radiation. How MRI works is that it excites and detects changes in protons found in the water that makes up living tissues. They take pictures of the inside of the body and analyse the information given. The scan takes between 15 to 90 minutes. In other words, if you have to determine whether you have cancer or not, and if so, you would have to measure how big it is and whether it has spread. When you lie under the powerful scanner magnets, the protons in your body line up the same direction, in the same course of action that a magnet can stick onto things. Short bursts of waves are then sent to certain areas of the body, knocking protons out of alignment.  It is often used for treatment monitoring, disease detection and diagnosis. Beyond that, researchers in Japan used MRI scans to reveal the images that patients were seeing as they entered into an early stage of sleep. They claimed in the Journal Science that they could accomplish it with 60% accuracy (Morelle B, 2013). When investigating, scientists also discovered that our stages of consciousness changes significantly during stages of deep sleep (REM sleep) and turns out our brains are more active than we thought. My point is, sleeping is essential but vivid nightmares can impact your daily life - a person's ability to fall asleep may be hampered by frequent nightmares, which can ultimately lead to tiredness during the day. Dreaming can also affect a person's ability to process other people's positive emotions, resulting in a higher level of social competence. 

Sleep study

The other sleeping test that patients could use to identify possible disruptions in the pattern of their sleep is Polysomnography monitors -  also called a sleep study, is a comprehensive test used to diagnose sleep disorders. For this examination, you will go to a sleep lab that is set up for overnight stays (usually in a hospital or sleep centre). While you sleep, an EEG (headset to detect electrical brain waves through electrodes arranged along the patient's scalp) monitors your sleep stages and the cycles of REM (rapid eye movement) and non REM (non rapid eye movement) sleep you go through during the night. They generally record your breathing rate, airflow, brainwaves, body position, oxygen levels in your blood, limb movement  and heart rate as well as eye snoring and other noise you may make as you sleep during the study. In addition to helping diagnose sleep disorders, polysomnography may be used to help initiate or adjust your treatment plan if you have already been diagnosed with a sleep disorder. On top of that, polysomnography is occasionally done during the day to accommodate shift workers who mainly sleep during the day. Most people believe that participating in this sleep test is worth the cost and is a non-invasive, painless test ranging from $943 to $2798. though there are side effects. The most common side effect is skin irritation caused by the attached sensors used to your skin. It is recommended to people who have struggles with sleeping and is one of the sleeping experiments invented. This could perhaps be caused by lack of sleep, irregular sleep schedules, physical illness and stress, to emphasise, this could possibly link to why some patients started having health issues such as insomnia and sleep deprivation. 

Conclusion

We can therefore see that sleep is essential for all organisms and can significantly benefit your physical, mental and emotional health and state. To further restore all the information you’ve gained and store it for future use; giving your body a well-deserved rest to heal itself and clears out any unwanted memories or toxic waste - conserving and strengthening our memories as it enters the rapid eye movement (REM sleep). With an adequate amount of sleep per week can exceptionally decrease the risk of memory loss and short life deficiency as well as disorders and afflictions. Scientists demonstrated the effects of patients who do not acquire enough sleep and observed effects it had on the patient's body and how their body reacts to it. Concluding that lack of sleep can trigger mania in people and start to hallucinate. Moreover, people who struggle to sleep due to inconsistent sleep schedules etc. can investigate using the MRI technology which is often used for detecting diseases and measures your brain activity while we sleep. Scientists have discovered a way to “read” dreams and reveal images people were seeing with 60% accuracy taking around 15 to 90 minutes. This test is similar to a sleep lab although the costs and methods are different. It is used to identify any disrupted patterns and what is happening in your body while you sleep. This conveys how important it is to receive enough sleep day by day to keep a healthy and balanced lifestyle. To sum up, it gives your body time to repair and restore to function, conserve energy and decrease the risk of metabolism. Besides coinciding memories and enhancing immunity for you to stay fit and active along with brain flexibility - the brain's ability to adapt to any new changes.

References 

AASM Sleep education 2018, Sleep and Caffeine, Sleepeducation, viewed 9 March 2022 <https://sleepeducation.org/sleep-caffeine/> 

BBC News 2013, Scientists ‘reads dreams’ using Brain scans, BBC News, viewed 9 March 2022, <https://www.bbc.com/news/science-environment-22031074#:~:text=Scientists%20have%20found%20a%20way,do%20this%20with%2060%25%20accuracy. > 

Dr. Binocs, 2019, Why do we sleep? Youtube, viewed 3rd of March 2022, <​​https://youtu.be/CoCL0IB4u4g> 

No sleepless nights 2021, 10 Sleep Deprivation Experiments, No sleep less night, viewed 9 March 2022, <https://www.nosleeplessnights.com/sleep-deprivation-experiments/> 

PubMed.gov 1997, The pioneering experimental studies on sleep deprivation, PubMed, viewed 9 March 2022, <https://pubmed.ncbi.nlm.nih.gov/9322273/>