The Functions of Sleep
FUNCTIONS OF SLEEP:
Sleep has not one main function but many.
A most popular theory on why we sleep is the restorative theory of sleep:
Restorative Theory: the theory of sleep that states that we sleep in order to replenish the processes of our minds and bodies that are depleted during the coarse of everyday life.
Increases in low wave sleep correlate with increases in physical activity
During REM sleep, proteins and other cellular components are returned to body
But is the restorative theory valid?
"Second Wind Phenomenon," the fact that people's sleepiness disappears when they have not slept counters the restorative theory.
Studies have shown that napping or just resting in bed are equally capable of improving mood.
During Sleep: blood flow in the cerebral arteries is elevated, heart and respiration become irregular, brain activity is elevated in certain areas.
Another function of sleep is the Adaptive Non-responding Theory:
Adaptive Non-responding Theory: the evolutionary theory of sleep that suggests that sleep and inactivity at night have survival value.
Most recently (1988) Wilse Webb, one of the leading researchers on sleep for over 30 years has suggested a theory that combines the best explanatory features of the restorative and adaptive Non-responding theory.
Webb suggests that sleep is a function of sleep demand, circadian tendencies, & behaviors that promote or inhibit sleep.
BIOLOGICAL RHYTHMS AND ALERTNESS:
Our biological clocks allow us to keep time in a changing world.
Circadian Rhythm: internal biological rhyth...
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... (1) sleep attacks; (2) cataplexy-sudden loss of muscle tone; (3) sleep paralysis; & (4) auditory, visual, or tactile hallucinations.
SIDS (Sudden Infant Death Syndrome): during sleep, a sudden inexplicable death of an infant who has been in perfectly good health.
Sleep Apnea: a rare sleeping disorder in which the person stops breathing momentarily.
Characteristically sufferers of sleep apnea are male, overweight, have high blood pressure and will experience fatigue, morning headaches, sleepiness and loss of memory but mainly FEAR of death in the night.
Somnambulism: sleep walking occurring during stage 4 sleep that usually involves repetitive acts performed while asleep that are not recalled once the person wakes.
Sleep Talking: talking occurring stage 1 of sleep, when a person is "half asleep and half awake."
Sleep deprivation is a commonplace occurrence in modern culture. Every day there seems to be twice as much work and half as much time to complete it in. This results in either extended periods of wakefulness or a decrease in sleep over an extended period of time. While some people may like to believe that they can train their bodies to not require as much sleep as they once did this belief is false (1). Sleep is needed to regenerate certain parts of the body, especially the brain, so that it may continue to function optimally. After periods of extended wakefulness or reduced sleep neurons may begin to malfunction, visibly effecting a person's behavior. Some organs, such as muscles, are able to regenerate even when a person is not sleeping so long as they are resting. This could involve lying awake but relaxed within a quite environment. Even though cognitive functions might not seem necessary in this scenario the brain, especially the cerebral cortex, is not able to rest but rather remains semi-alert in a state of "quiet readiness" (2). Certain stages of sleep are needed for the regeneration of neurons within the cerebral cortex while other stages of sleep seem to be used for forming new memories and generating new synaptic connections. The effects of sleep deprivation on behavior have been tested with relation to the presence of activity in different sections of the cerebral cortex.
We live our entire life in two states, sleep and awake1. These two states are characterized by two distinct behaviors. For instance, the brain demonstrates a well-defined activity during non-REM sleep (nREM) that is different when we are awake. In the study of sleep by Huber et. al., the authors stated that sleep is in fact a global state2. It is unclear whether this statement means that sleep is a state of global behavioural inactivity or the state of the global nervous system. The notion that sleep is a global state of the nervous system served as basis for sleep researchers to search for a sleep switch. The discovery of the sleep switch, in return, provided evidence and enhanced the notion that sleep is a global state of the nervous system. The switch hypothesis developed from the fact that sleep can be initiated without fatigue and it is reversible1. It was hypothesized that there is something in the brain that has the ability to control the whole brain and initiate sleep. Studies have found a good candidate that demonstrated this ability3. They found a group of neurons in the Ventrolateral Preoptic (VLPO) nucleus. It was a good candidate because it was active during sleep, has neuronal output that can influence the wakefulness pathway, and lesion in the area followed reduce sleep3. The idea that there is something that can control the whole brain and result sleep state supports the idea that sleep is a global state of the nervous system.
Sleep is one of our basic needs to survive, however in the modern days sleep deprivation in increasing more and more each day, causing accidents and medical problems for the people and the community. This essay will look at the meaning of sleep and sleep deprivation and the basic perspectives on what motivates sleep and sleep deprivation with the five perspectives; evolutionary, psychodynamic, behaviourist, cognitive and the hierarchy of needs. This essay will also evaluate the best perspective to eliminate sleep deprivation with the cases studies discussing the general hypothesis of sleep and sleep deprivation.
Another theory for why we sleep is based on the belief that sleep in some way serves to restore what is lost in the body while we are awake. Sleep provides an opportunity for the body to repair itself. In recent years, these ideas have gained support from evidence collected in human and animal studies. One of these studies have shown that animals deprived entirely of sleep lose all immune function and die in just a matter of weeks. This is further supported by findings that many of the major restorative functions in the body like muscle growth and repair, as well as bone growth mostly happen during
Engage: Sleeping is an activity that everyone of us is very familiar with. However, sleep can be detrimental to certain types of people, and can limit their interactions with the world. Narcolepsy is a sleeping disorder, that puts people and the people around them be at risk of danger. I hope my speech will help you identify someone with narcolepsy.
Many studies of the role of sleep are partial or total sleep deprivation studies which support Oswold’s restoration theory. One of these supporting studies was Dement’s. He deprived participants of REM sleep and consequently found that they increased their number of attempted REM stages from 12 to 26 over 4-7 nights. During their first uninterrupted night, participants increased their REM sleep by 10% which is known as REM rebound. This suggests the importance of REM and the possibility that the purpose of sleep is to get into REM sleep. The participants reported anxiety, irritability and difficulty concentrating which shows that REM sleep is needed to avoid these affects and enable brain recovery which corresponds with Oswold’s theory. Even so, Dement’s study has low ecological validity, it has low population validity because there were only 8 participants and they were a self-selected sample. Participants would probably have shown demand characteristics because the experiment took place in a lab. It also has low mundane realism because people would not usually sleep in a lab and be interrupted repeatedly.
Sleeping is something that is an essential part of human nature and is a must in order for one to be a functional human being. Sleep is an idea that is accompanied by many wives’ tales, including the ideas that one needs seven to eight hours of sleep each night and alcohol helps one fall asleep and sleep more soundly. One myth about sleep is that during sleeping, one is in a state of nothingness. In truth, however, it has been discovered that during sleep the brain is active, variations in heartbeat and breathing occur, and the eyes and ears are active throughout the time of sleep. These activities during a person’s sleep are important because they help that person be more aware, awake, and alert during consciousness. If all of these important activities occur during sleep, why is it that people are so willing to short themselves of this vital activity? Although much about sleep still remains a mystery, research and experiments continue to show how important sleep is to each and every person. Throughout this paper, I will discuss sleep and the effects that it has on performance and health, especially in college students. A college student’s sleeping pattern is a reliable indicator to their level of performance in the classroom and other school-affiliated activities, as a lack of sleep leads to decreased performance. Sleep is directly related the level of performance and health in an individual; the more rested a person is, the better that person will perform and feel (Dryer, 2006).
Parasomnia refers to a wide variety of disruptive, sleep-related events or, "disorders of arousal." These behaviors and experiences occur usually while sleeping, and most are often infrequent and mild. They may however happen often enough to become so bothersome that medical attention should be sought out. "Parasomnias are disorders characterized by abnormal behavior or physiological events occurring in association with sleep stages, or sleep-wake transitions."(DSM pg. 435)
Each night, the average person spends approximately 7-9 hours giving their bodies a restful vacation in the land of dreams. Considering this, we spend 1/3 (or 25 years) of our entire lives engaging in this idle activity. Although these numbers can appear as a waste of time in our every day lives, sleeping and/or napping is the energy that helps fuel our bodies to function correctly. Sleep is a necessary function in our every day routine in order to make our brains function at the most efficient level. As we sleep, the brain helps us to recuperate and regain strength by “restoring and repairing the brain tissue” (Myers, 2010, p 99). Without this reviving process, we would all eventually deteriorate. By impairing the sleep deprived mentally and physically, it can potentially cause serious harm. We must fade our conscious mind, and let our mind relax within subconscious state.
The phenomenon of sleep paralysis can be a frightening experience: many who suffer can feel tremendous anxiety and fear, even though occurrences are considered as harmless as a bad dream. The disorder does not discriminate on the basis of race or gender, but age sometimes is a factor. Treatment for sleep paralysis is limited; in general, doctors treat the disorders linked to sleep paralysis such as sleep apnea or narcolepsy. Sleep paralysis continues to be one of the many mysteries of the human brain, which science will continue to investigate.
Sleep disorders are an underestimated public health concern considering that fifty to seventy million Americans are affected. Technological advances in the field of sleep have facilitated various theories to explain the need for and the purpose of sleep. Scientist have uncovered many types of sleep disorders such as insomnia, sleep apnea, and narcolepsy. Sleep disorders affect men ,women, children, the elderly, and the obese in different ways. Factors such as the number of children and the effects of menopause have been studied to determine their effects on sleep. Various treatments have been utilized ranging from non-pharmacologic to pharmacologic methods. Scientist have pinpointed areas of the brain that are involved in sleep deprivation and hormones that ultimately affect sleep.
Kelly, W. E., Kelly, K. E., & Clanton, R. C. (2001). The relationship between sleep
Central idea : Sleep is vital to our health and well-being throughout our life, therefore, in order to protect our mental and physical health, quality of life, and safety, we must get an enough quality sleep at the right times.
Stage N 1 is sometimes referred to as somnolence or drowsy sleep, can be identified by sudden twitches, jerks, and loses some muscle tone. Some experience hallucinations during this stage and have little conscious awareness of the external environment. This stage can be identified on an EEG with the displays of theta raves. Stage N 2 can be seen by muscular activity measured by EMG decreases, and the EEG displaying sleep spindle and k complex. During this stage conscious awareness of environment disappears, occupying 45–55% of total sleep in adults. Stage N 3 can be filled with parasomnias like night terrors and sleepwalking, this stage can be seen on an EEG the delta waves will be slightly smaller those in Stage N 4. Rapid eye movement sleep, or REM sleep a rapid low-voltag...
Important public policy issues have arisen in our modern 24-hour society, where it is crucial to weigh the value of sleep versus wakefulness. Scientific knowledge about sleep is currently insufficient to resolve the political and academic debates raging about how much and when people should sleep. These issues affect almost everybody, from the shift worker to the international traveler, from the physician to the policy maker, from the anthropologist to the student preparing for an exam.