During this paper I plan to shed some light on that and other topics such as what it really is, what goes on during sleep, the effects on the brain, importance of the duration of sleeping periods, and the importance of sleeping positions. I plan to show the importance of sleep and the many effects it can have on our lives.
The study of sleep is called Polysomnography, and it is rather hard to collect data because when the data can be collected most people are asleep meaning the scientists have to stay awake. The study of sleep is mostly used to diagnose sleep disorders but along with that scientists have made many discoveries. As stated in The Oxford Companion to the Mind sleep specifically is “a healthy state of inertia and unresponsiveness that is recurrently imposed by unknown mechanisms within the nervous system.” (Gregory). As it says there are unknown mechanisms that cause us to go into a state of unconsciousness. While in this state our body goes through many processes and there are even two different types of sleep.
The first type of sleep that takes up 80% of our nightly rest is orthodox sleep or NREM(Non-Random Eye Movement) and the other is called paradoxical sleep or REM(Random Eye Movement) with about 20% of time sleeping (Gregory). Within the NREM cycle there are four more stages slowly progressing into deeper sleep but recently scientists have grouped the third and fourth stages together seeing as there is not much difference between the two. Within those four stages of sleep there are many processes and changes that happen to the body. During the first stage or N1 is when sleep is the lightest and one passes from awake to asleep. During the second stage or N2 the body temperature begins to drop. Most of the changes occur during the former third and fourth stages or N3. Blood pressure drops and the muscles are the most relaxed during the deepest and most restorative part of the sleep cycle (What Happens). Although some know the REM cycle as deep sleep it is really not deeper than the other type of sleep. While in paradoxical sleep or REM the body tends to relax more and the brain receives more blood flow. This is usually when the brain is more active and when dreams tend to happen. While dreams can happen during the four stages of NREM they are usually less vivid and shorter. The reason why our dreams may seem so real to us is because the two parts of our brain that have the most activity during REM sleep are the parietal lobe which is in charge of visual imagery and the amygdala and paralimbic cortex which have to deal with emotional processing (Purves). These two combined cause us to believe what we are seeing is real and when we wake up we try and relate it to our lives because of the emotional connection. In the following diagram of a sleeping male over an eight hour period it shows more accurately the changes in different bodily functions when passing through the different stages of sleep.(see fig. 1)
EOG (Electrooculography) in the graph represents eye movement. As you can see during REM, or Rapid Eye Movement, the eyes tend to move more than during the other cycles. EMG (Electromyography) refers to general muscle movement. Along with these processes, the diagram shows changes in heart rate, respiration and even penile erection. As you can see from the graph, the longer an individual has been asleep, the longer the duration of their REM stages will be. Although REM sleep causes more activity within the body-spiking body movement before and after the REM period-during REM the body is mostly inactive .
Although we do not completely understand why we sleep besides the fact that we get tired, sleep for our body is very necessary. This time when our muscles can relax and repair from all of the activities during the day. Many of the benefits come from the hormones released as we sleep, one of which is a hormone that promotes growth throughout the body. Sleep can also help us with weight gain “by helping to regulate levels of the hormones ghrelin and leptin, which play a role in our feelings of hunger and fullness. So when we’re sleep deprived, we may feel the need to eat more, which can lead to weight gain(What Happens).” It has many effects on our daily life and can even help with memory recall. In a study done by Steffen Gais, Brian Lucas, and Jan Born from the Department of Neuroendocrinology at the University of Lübeck in Lübeck, Germany they tested various high school students ability to memorize German vocabulary with no previous knowledge. In the article they go on to describe how they carried out the experiment:
Subjects learned on each occasion one of four 24-pair English–German vocabulary lists, presented on a sheet of paper with a time limit of 10 min to learn the whole list. Lists consisted of 10 dissimilar and five cognate nouns and five verbs. In addition, two pairs of nouns in the beginning and in the end of each list were excluded from later analysis to rule out recency and primacy effects. Learning took place either at 8 a.m. or at 8 p.m. Immediately after learning, recall was tested to see how many words were initially retained. Recall was tested again after 24 h or 36 h at 8 a.m. or 8 p.m. The recall test was in written format, with the English words given in a different order than during the original presentation. Recall was measured as the number of correctly remembered words; forgetting is given as the average individual percent change in recall performance across the retention interval.(Gais, Steffen, et al)
They also tested for sleep deprivation after the learning period and found that “Subjects remembered clearly more of the learned vocabulary when they had slept during the night following learning than when they had stayed awake(Gais, Steffen, et al).” They concluded that a learning period followed by sleep can have a positive effect on declarative memory. This means that if you want to remember something you need to learn its best to do it within the few hours before you go to bed. They also noted that there was no difference in the intervals between testing the memory. They tested at 24 hours and 48 hours and found almost the same results meaning that retention is the same when the material is studied before going to bed. Overall good sleep results in better memory, an improved immune system, and rebuilds our cells helping us to live longer.
Now I started this paper saying we Spend almost 1/3 of our lives sleeping now the question is is all that time really necessary to get the same results? Or on the other hand is there such things as too much sleep? First off lack of sleep causes many problems and after passing sixty hours without sleep it is very hard to stay awake and the person will have microsleeps where they remain awake but unconscious. But once you have passed 240 hours the mind adapts into a more dulled state with slowed reflexes (Gregory). In an experiment with over 10,000 people globally that was published by five scientists (Conor J Wild, Emily S Nichols, Michael E Battista, Bobby Stojanoski, Adrian M Owen) they tested to see the effects of amount of sleep on general brain performance in various tests. They concluded that “cognitive performance, measured using a set of 12 well-established tests, is impaired in people who reported typically sleeping less, or more, than 7–8 hours per night (Wild, Conor J, et al).” They went as far as to find that even one night of good sleep can greatly improve performance in those who usually do not get the suggested 7-8 hours a night. For those without the problem of not sleeping enough and sleep more than the 7-8 hours drawbacks were also found such as “impairments in their overall cognition, and in their reasoning and verbal abilities (Wild, Conor J, et al).”
Now as you can in this diagram(see fig. 2) there are many long term as well as short term effects that result from sleep disruption. Sleep disruption can be caused by many factors such as “consuming excessive amounts of caffeine, attending university, excessive noise, excessive light, anxiety, worry, insomnia, obstructive sleep apnea, pain or diabetes”(Medic, Goran Eh, et al). All of these among others can have lasting effects as seen in the diagram that it may start out as stress but then turn into obesity, cancer, and even death. These stats are the ones that have the most influence on someone when deciding if it is worth it to stay up a few extra hours say to finish a project or assignment or on the other hand to make a habit of sleeping in everyday getting more than necessary. The time we sleep is very important as you can see and over time will define many aspects of our health and even possibly our life expectancy.
Are you a belly sleeper? A back sleeper? Or maybe even in fetal position? We all sleep differently but is there a bad way to sleep? Or a way that is most beneficial? In an article posted by the National Sleep Foundation on Sleep.org it says that the healthiest but also one of the least common ways to sleep is on your back. This method of sleeping “allows your head, neck, and spine to rest in a neutral position. This means that there’s no extra pressure on those areas, so you’re less likely to experience pain (Sleep Position).” The only drawbacks for sleeping on your back are that you are more prone to have acid reflux and snoring can be worse. After sleeping on your back comes sleeping on your side with your legs relatively straight. This provides relief for back and neck pain and prevents acid reflux cause your esophagus is higher than your stomach. The one downside that you may not think of is wrinkles. They are caused by your face being pressed up against a pillow. Next is the fetal position but only if it is relaxed. Laying with your knees tight up to your chest and your chin down will cause tightness and rougher sleep. This position is also very beneficial if you are pregnant. Laying on the left side will relieve pressure from the liver in pregnant women. Finally coming in last is sleeping on your belly. This one is the worst for you seeing that it’s hard for your spine to be in a relaxed or neutral position. The only good benefit from this is that it’s good for those who have snoring problems. Out of the many different ways there are many different levels of comfort for individuals. It depends on one to make the changes for the benefit of his/her back or snoring problems seeing as those are the two most prominent causes from the different positions.
In this paper, I have discussed various factors that affect sleep; such as, the amount of time and the position in which one sleeps, and the resulting “good” or “ bad” sleep quality. Because we literally spend 1/3 of our lives unconscious, these are factors that are essential to understand. The time we spend sleeping truly is precious and will have drastic effects that span across a lifetime.
Works Cited
- “Figure 28.6” NCBI, Accessed 26 February 2020, www.ncbi.nlm.nih.gov/books/NBK10996/.
- “Figure 1” NCBI, Accessed 26 February 2020, www.ncbi.nlm.nih.gov/pmc/articles/PMC5449130/
- Gais, Steffen, et al. “Sleep after Learning Aids Memory Recall.” Learning & Memory, Cold Spring Harbor Lab, 28 Mar. 2006, learnmem.cshlp.org/content/13/3/259.full.pdf html.
- Gregory, Richard. The Oxford Companion to the Mind. 2nd ed., Oxford University Press, 2005.
- Medic, Goran Eh, et al. “Short- and Long-Term Health Consequences of Sleep Disruption.” Nature and Science of Sleep, Dove Medical Press, 19 May 2017, www.ncbi.nlm.nih.gov/pmc/articles/PMC5449130/.
- Purves, Dale. “Stages of Sleep.” Neuroscience. 2nd Edition., U.S. National Library of Medicine, 1 Jan. 1970, www.ncbi.nlm.nih.gov/books/NBK10996/.
- “What Happens When You Sleep?” National Sleep Foundation, 2020, www.sleepfoundation.org/articles/what-happens-when-you-sleep.
- “Which Sleep Position Is the Best?” Sleep.org, National Sleep Foundation, 2020, www.sleep.org/articles/best-sleep-position/.
- Wild, Conor J, et al. “Dissociable Effects of Self-Reported Daily Sleep Duration on High-Level Cognitive Abilities.” OUP Academic, Oxford University Press, 13 Sept. 2018, academic.oup.com/sleep/article/41/12/zsy182/5096067.
