Discovery: Nature and function of sleep
QUE: Write about what psychologists have discovered about the nature and function of sleep and how these findings can be put into practical use.
Psychologists have done researches in the field of sleep.These findings intended to explain what sleep is and its function.In relation of the discoveries like electroencephalographs and electrocalograph s among others, psychologists were able to identify the four stages of sleep.Through such discoveries psychologists also managed to discover the functions of sleep to the human body as a whole, such include restoring body tissue,increases the immunity of the body among others.Therefore the various discoveries concerning the nature and function of sleep will be explained in this essay.
Sleep has been defined by many psychologists as a state of altered consciousness. Kasschau(2003) defines consciousness as a state of awareness.Sleep experiments were conducted in sleep laboratories and these experiments were aided by the development of electroencephalographs (EEGs). This technology helped psychologists to identify the stages of sleep. The EEGs examine the electrical activity of relatively large areas of the brain and related physical responses of the body. The brain waves are plotted on graph paper or on a computer screen. The pattern the brain waves produce gives researchers an image of the brain activity, when people are awake or asleep. Brain waves vary in height of the waves (amplitude) and the number of waves per second (frequency). These are usually categorized as alpha, delta or theta waves. Sleep is affected by biological rhythms or periodic physiological changes. Biological rhythms are regular, periodic changes in a body’s functioning. There are three types of biological rhythms, these include Circadian rhythms and this is when biological cycles occur about every twenty-four hours. Sleep follows a circadian rhythm. Hormone secretion, blood pressure, body temperature, and urine production also have circadian rhythms. a group of brain cells in the hypothalamus called the suprachiasmatic nucleus (SCN). The SCN works very much like an internal clock—signaling other brain areas when to be aroused (awake) to start the day and when to shut down (sleep) for the day. melatonin, the hormone secreted that facilitates sleep. Melatonin regulates one`s circadian rhythm and helps one get to sleep. The SCN rests in a part of the brain called the hypothalamus, just above the point where the optic nerves cross. Light that reaches photoreceptors in the retina (a tissue at the back of the eye) creates signals that travel along the optic nerve to the SCN. Signals from the SCN travel to several brain regions, including the pineal gland, which responds to light-induced signals by switching off production of the hormone melatonin. The body’s level of melatonin normally increases after darkness falls, making people feel drowsy.
There are also Infradian rhythms, Biological cycles that take longer than twenty-four hours. For example, women’s menstrual cycles occur about every twenty-eight days. Lastly there are Ultradian rhythms, Biological cycles that occur more than once a day. Sleep follows an ultradian rhythm of about ninety minutes as well as a circadian rhythm. Alertness and hormone levels also follow ultradian rhythms. Biological rhythms usually synchronize with environmental events such as changes in daylight. However, experiments have shown that many biological rhythms continue to have the same cycle even without cues from the environment. Such biological rhythms are endogenous, which means that they originate from inside the body rather than depend on outside cues.
To add on, when people are awake the brain emits beta waves. These are rapid with a high number per second of cycles, thus showing frequent impulses of electrical activity in the brain. When people are awake but relaxed the brain emits alpha waves which are somewhat slower and less frequent than beta waves. Apart from EEGs there are also electroculographs (EOGs) that record the eye movement and electrocardiographs (EKGs) that record heart activity. Thus in relation with the above mentioned one can note that the technological advancement equiped pshologists with the necessary tools to discover the nature of sleep
Psychologists have also discovered the two types of sleep, namely Rapid Eye Movement (REM) and Non Rapid Eye Movement (NREM). Under REM sleep people move eyes rapidly under the eyelids, whereas in NREM there is no movement under the eyelids. In these sleeps, bodies and brains experience different activities. Consequently, NREM has four stages and stage one is characterized by theta waves. During this stage brething rate and heart rate slow down, one may experience the sensation of falling or floating (hypnic myoclonia). Stage two is characterized by sleep spindles and last for about twenty minutes. Pastorino & Portillo (2011) defines spindlers as a pattern of slower theta waves sporadically disrupted by bursts of electrical activity. In addition Pastorino & Portillo go on to say during stage two breathing, muscle tension,heart rate,and body temperature continue to decrease. It is during this stage of sleep that people process both easy and complex skills learnt during the day.
Stages three and four of sleep are refered to as slow wave sleep Pastorino&Portillo(2011). In stage three people begin to show delta brain wave patterns. People enter the last stage of sleep when a constant pattern of delta waves emerges. Stage four is the deep sleep. The body is extremely relaxed, heart rate ,respiration,body temperature and blood flow to the brain. Besides these four basic stages of sleep, another, unique, stage of sleep exists, REM. This stage gets its name from the darting eye movements that accompany it (rapid eye movement), as indicated by the EOG. Interestingly, it is also characterized by a sudden and dramatic loss of
muscle tone, which is measured by the EMG. In fact, the skeletal muscles of a person during
REM sleep are effectively paralyzed. This stage is also, associated with a unique brain wave
pattern too, in that during REM sleep a sleeper`s brain waves demonstrate characteristics that are similar to waking sleep, a combination of alpha, beta, and desynchronous waves.
Most importantly to psychologists, this is the stage of sleep most associated with dreaming. REM sleep stimulates the brain regions used in learning. This may be important for normal brain development during infancy, which would explain why infants spend much more time in REM sleep than adults. When a sleeper in a research lab begins to exhibit the physiological indices of REM sleep, and they are awakened, the great majority of the time they will report that they were having a vivid, story-like, dream. During other stages, on the other hand, they normally do not report dreaming. Interestingly enough, it was not until 1953, that Dement and Kleitman discovered that the fact that this unique stage of sleep was associated with dreaming. This was very exciting and profound to the researchers, since dreams were so important a subject in the study of psychology. Therefore one can note the nature of sleep through the explanations above.
In addition to the nature of sleep is the functions of sleep such include restoring body tissue. Sleep allows the immune system and organs to replenish lost reserves of energy and to repair any cellular damage. Deep sleep coincides with the release of growth hormone in children and young adults. Many of the body’s cells also show increased production and reduced breakdown of proteins during deep sleep. Since proteins are the building blocks needed for cell growth and for repair of damage from factors like stress and ultraviolet rays. The body also prepares itself for the next day and ensures the health of the body. Sleep also activates a growth hormone which facilitates physical growth during infancy,childhood and the teen years ( Gais, Hullemann, Hallschmid& Born 2006). Genital arousal happens during REM. In women, the clitoris becomes swollen with blood, and vaginal lubrication increases. Whilst in men, the penis becomes erect. This indicates that sleep is essential for hormonal growth. Other scholars like Murphy&Delanty(2007),Orginska &Pokorski(2006) argue that lack of adequate sleep can also affects energy levels often making us feel drowsy and fatigued. It become clear with the above mentioned that sleep is a necessity in people`s lives.
Moreover,sleep plays a pivotal function of increasing immunity to diseases. During sleep, the production of immune cells that fight off infection increases. Beardsley(1996); Born,Lange,Hansen,Molle&Fehm(1997) say therefore your immune system is stronger when you receive the appropriate amount of sleep. This is evident in sick people, one can notr that sick people are encouraged to sleep when they are ill so that the body can boost up the immune system. As a result lack of sleep makes people vunarable to diseases. Thus sleeping functions as immunity of the body
Furthermore,sleeping is also responsible for making one mind stay alert. When people do not get enough sleep they are more likely to be inattentive and easily destructed (Jennings,Monk&Mollen,2006). Sterade & McCarley (1990) suggest that sleep makes the body more sensitive to neropinephrine. This is noted when people do get enough sleep they tend to be in a position of not being able to pay attention to their surroundings. They also feel tired and lazy sis then proves that sleep has a remarkable function in the human body and should be part of every human`s daily activities.
Moreso, sleep serves the function of learning and memory. When people sleep emotional experiences as well as information that one has received and rehearsed are most likely to be remembered. Sleep allows people to better store what material was actually processed during studying. Sleep`s connection to memory processing as argued by EllenBogen,Hu Payne, Titone& Walker(2007) also explain why problem solving seems to improve after a night`s sleep. This is evident when school students wake up to read because the mind would have been rested and cleared. Therefore the function fo sleep becomes evident when one takes into consideration the afore mentioned.
Apart from the above mentioned, sleep also enhances people`s mood. Sleep activates many chemicals that influence emotions and mood. Consequently if one is deprived of sleep, one is more likely to be irritable,cranky and unhappy,in addition to being tired (Durmer & Dinges,2005). The signs can be noted in children adolescents and young adults, perhaps because as people get older they get better at regulating emotions such that they may be less affected by lack of sleep.
On the other hand these discoveries can be put in practice by explain sleeping problems Many people with total blindness experience life-long sleeping problems because their retinas are unable to detect light. These people have a kind of permanent jet lag and periodic insomnia because their circadian rhythms follow their innate cycle rather than a 24-hour one. Daily supplements of melatonin may improve night-time sleep for such patients. However, since the high doses of melatonin found in most supplements can build up in the body, long-term use of this substance may create new problems. Because the potential side effects of melatonin supplements are still largely unknown, most experts discourage melatonin use by the general public.
In summation,one can say that sleep is a necessity not a luxury for it keeps the body healthy,keeps it alert among others. All these were discovered through the EEGs, EKGs and EOGs that psychologists used in finding out the nature of sleep as well as the nature of sleep.
REFERENCES
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Gais, S., Hullemann, P., Hallschmid, M., & Born, J. (2006).Psychoneuroendocrinology
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