Functions and brain mechanisms of sleep

Functions and psyche mechanisms of stop forty winks, it is the deposit in which we spend patronisely of our lives yet so little is known about it. It has long interest psychologists and legion(predicate) commence sought to unravel its mysteries. Yet like entirely other behaviours forty winks merchantman be examined using the same biological, mental and environmental methods that argon so effective in other areas. Defined, eternal rest period is a natur e really(prenominal)y recurring introduce which is characterized by reduced or absent consciousness, relatively suspended sensorial activity, and inactivity of nearly all voluntary energys. yet this explains what is visible, over the years theorists tried to explain what is contingency biologically during rest period.Up until the 1950s exploreers seed that calm occurred overdue to an overtaxing of the headland, that the constant sensory stimulation that bombards the conceiver during the day renders it unable to chief(prenominal)tain a argus- kerneld level of brain activity. They to a fault believed that achieving this state was helped by the occurrence of the shadower and silence of night. Sleep at this time was in like manner viewed as a homogeneous state and as a result of this many researchers viewed it as relatively uninterest. This may be a reason why very little scientific vigilance was put on the topic for so long. In circumstance dream interpretation garnered far more attention at this time (Dement, 1998). This passive process theory was simply dropped when experimenters record eye bowel movement and muscle tension during sleep. This led to the groundbreaking uncovering that there were in incident two different classes of sleep, rapid eye movement (rapid eye movement) and non-rapid eye movement sleep(nonrapid eye movement sleep) (Watson, Breedlove Rosenweig, 2010).In this essay sleep, both rapid-eye movement and slow-wave, pull up stakes be explored. Also set out leave alone be the main functions of sleep and what whoremonger happen when a person is take of sleep. Finally the sleep disorder narcolepsy allow for be discussed as it is an a good deal misunders alsod disorder which destines the mal effects when take in over when to sleep is lost.Sleep can be divided into 5 power points, 4 of these details are during NREM with the final tier being REM sleep. These stages are measurable by the patterns of electrical activity in the brain. When awake the brain shows patterns of beta waves. These go through a high frequency and low amplitude. When in a state of relaxation the brain shows waves with lower frequencies, these are called alpha waves (Passer Smith, 2009)Stage 1 of NREM occurs just as the corpse drifts into sleep. At this stage the brain begins to demonstrate theta waves. These waves are slower a cod than those measured during a dull state and have irregular frequencies, the heart rate also slows and muscle tension is reduced. This stage normally lasts several minutes, giving way to stage 2. here(predicate) the brain shows short (1-2 seconds) periodic bursts of brain activity. These bursts are called sleep spindles. Interesting to note is that often peck deny that they were even hypnoid if they are awakened during either the first or second stage. As the body drifts even deeper into slumber stage 3 is reached, here delta waves are the most dominant. These are of an extremely low frequency and have full-size amplitude. Stage 4 is very similar to stage 3 and shows foster lowering of frequency and expansion of amplitude. Stages 3 and 4 are also fewtimes referred to as slow-wave sleep (SWS) by some researchers. After range this stage the body then cycles through the previous stages and generally aft(prenominal) 60-70 minutes of falling asleep the body has g mavin through a cycle of stages 1-2-3-4-3-2. It is at this point that brain activity changes alarmingly and a brand new and unique stage of sleep emer ges. This new stage is called rapid-eye movement (REM) sleep (Watson et al, 2010).This stage of sleep was discovered by Aserinky and Klietman in 1952 and is characterised by high brain arousal, rapid eye movement and frequent vivid dreaming. These researchers found that during this phase the sleeper showed bursts of muscular action which resulted in the persons eyes moving rapidly underneath the eye lid, this happened around all(prenominal) minute during REM sleep. People that were awakened during this stage frequently give out having a dream, this is even true of people who before claimed to have neer dreamed (Passer Smith, 2009). Brain activity increases to daytime levels and the body also becomes physiologically aroused, with more rapid breathing and a swifter heartbeat. Another characteristic of this stage of sleep is that the bodies of both men and women become aroused, regard s wakeful of dream content, with penile erections in men and vaginal lubrication in women. The b rain also can send signals to the muscles of the arms legs and torso which make them become very relaxed, they once in a while twitch but movement is not possible at this time. This is sometimes referred to as sleep paralysis.After an average of 90 minutes the body begins the cycle of stages anew, however with each recurrence REM sleep lasts longer, alimentation into the time previously spent in stage 3 (Passer Smith, 2009).The brain controls the passage of the body through sleep however no hit part of it is solely responsible for it. Various mechanisms in the brain control the different aspects of the sleeping body, areas on the base of the forebrain are attached with the act of falling asleep. Other sections in the brain active during sleep are certain areas in the brain stem which regulates REM sleep. Here neurons are contained which activate the other brain systems which are mandatory during REM such as those for the rapid-eye movement and muscular paralysis. Memories are ac cessed during REM sleep and this is also governed by these areas in the brain stem. This affects what is see during dreams(Watson et al, 2010).Having explored the biology pot sleep it is now worth looking at the benefits of sleep, both physiological and psychological. There are two major branches of thinking which explore the call into question of why do we sleep? These are the restoration representatives and the evolutionary/circadian models (Passer Smith, 2009).According to the evolutionary models sleep recharges run-down bodies, it allows us to recover from bodily and mental fatigue. This is largely supported by research in sleep deprivation. A good example of integrity of these studies is the world record start by Randy Gardener in 1964. He stayed awake for 11 days as part of a school science sensible project and he allowed sleep researchers to analyze him during this period. Over the first some days he was irritable, forgetful and nauseous, by the fifth day he began to experience periods of disorientation and had mild hallucinations and by the end he experienced slurred speech and finger tremors (Gulevich, Dement Johnson, 1966). This research clearly shows physiological and psychological problems that arise from sleep deprivation. However it has been proven that less sleep is needed as you age with older adults living healthy lives on only 5 or 6 hours sleep. In fact there is one example of a 70 year old woman who could rifle on 1 hour of sleep a night. Many researchers also believe that a cellular waste chemical called adenosine has a component part in the restorative functions of sleep. Adenosine is produced as cells produce energy. At high levels adenosine inhibits brain functionality and levels of it decrease during deep sleep (Passer Smith, 2009).Evolutionary/Circadian models state that the main function of sleep is prolonging a species survival relative to its environmental demands. It backs up its evidence based on the fact that preh istorically our ancestors had very little to gain by being active at night as nourishment gathering etc was much more easily accomplished in the day. The model puts forward the idea that over the course of the evolution of a species a circadian sleep is developed. This is a wake pattern that becomes heredity due to certain factors such as its status in the predator exploit relationship and its food requirements. Also researchers backing this model believe that sleep also evolved as a way of conserving energy, putting forward the fact that we use up to 25% less energy when asleep (Watson et al, 2010).A controversial theory on a benefit of sleep is one that links it to memory consolidation. The purpose of REM sleep remains uncharted and some have put forward the idea that it is a whoreson that the brain uses to consolidate memories, a process in which the brain transfers schooling to the long term memory. This consolidation hypothesis is however contradicted by the fact that stud ies show that even when a person has little or no REM sleep due to a side effect of anti-depressant drugs they show no impairment of long term memory capacity. This has led some to state that REM sleep is necessary on a purely biological level. These theorists believe that the body uses REM sleep primarily to bear the brain from long periods of low arousal as they believe this could have damaging effects. The true purpose of REM sleep is still debated (Watson et al, 2010).An interesting study by Paller and Voss provided evidence that suggests that when memories are accessed during dreaming they can be subtly altered by the dream. This has is to do with memory consolidation. There study showed that the brain does use dreams, at least on a refined scale, to aid in memory consolidation as has been previously known. However that the brain can alter these dreams is intriguing to say the least (Paller Voss, 2004).Whereas it has been discussed how too little sleep can impair the body, here, the sleep disorder narcolepsy will be explored, showing how a inability to stay awake can also cause problems to an individuals lifestyle. About 1 out of every 2000 people suffer from narcolepsy, those living with the disorder have to deal with daily bouts of drowsiness and uncontrollable sleep attacks where they can go into sudden sleep for less than a minute to a whole hour. Often these sleep attacks are accompanied by sleep paralysis or hypnagoic hallucinations. Some researchers believe that narcolepsy is a disorder involving an intrusion by REM sleep into open-eyed life. It is believed that narcolepsy is cause because of a chemical imbalance in the hypothalamus. There is no cure but some ant-depressant drugs appear to be effective in reducing episodes, this could be due to their suppression of REM sleep.In conclusion, research around sleep has come a long way since its modest beginnings. We now know far more about the biology behindhand sleep and yet much of it, includi ng REM sleep still confounds many researchers.This essay has also outlined the many benefits that sleep has, both physiological and psychological and has shown the difficulties that arise from a lack of it and has shed some light on the obscure and misunderstood sleep disorder narcolepsy. It is hoped that research will continue on in the future and hopefully the mysteries surrounding the state which we spend almost a third of our life in will be unravelled.