Research and theories of sleep
To talk about a concept, we must first be clear on its definition. Psychologists describe sleep as an altered state of consciousness. It is a resting state in which an individual becomes relatively quiescent and relatively unaware of the environment. During sleep, which is in part a period of rest and relaxation, most physiological functions such as body temperature, blood pressure, and rate of breathing and heartbeat decrease. The amount of sleep needed depends on both the individual and the environment. With the invention of the "Electroencephalogram" or an "EEG" as it is more commonly known has made it possible to monitor the brain's electrical activity. The EEG picks up and records electrical activity through electrodes attached to the scalp. The reading of a waking person is clearly different than that of a sleeping person. The EEG pattern of our brain during waking periods is very rapid, irregular and low on voltage. This means that many neurons are firing at different intervals and at different times, with different strengths too. This type of irregular electrical activity in the brain during wakefulness is called beta waves or beta activity. When we are relaxed, sitting in the sofa watching
Perhaps then it is the case that sleep has all these functions and more that we do not know about yet. The bottom line is that sleep is so essential that long periods of sleep depravation eventually results in stress-related deaths (this has happened with lab animals, and it is possible that the same can happen with us). Missing even one single night of sleep may affect our mental performance in decision-making on the next day. The conservation theory proposes that the main purpose of sleep is to conserve energy during times when (in animals) tasks like feeding and searching for a mate become impossible during the hours of darkness. Sleep therefore in humans represents a form of hibernation, and this follows from the fact that the body temperature, heart rate and therefore metabolism as well all decrease during sleep. It is also true that when food is in short supply that animals will send to sleep more. However, as with the example of lions before who eat very nutritious meals do tend to sleep for long periods, sometimes as much as 12-14 during the day. Sleep on the other hand is not a random process; instead, it is a very organized one. Through EEG readings Sleep has been separated into five stages. Stage 1-4 (non-REM sleep) followed finally by REM sleep. Once REM sleep is achieved, the cycle reverses itself and goes back though stages IV, III, II and again to III, IV and REM. Throughout the night, this cycle occurs at 90 to 100 minute intervals. Another theory - the Oculomotor System Maintenance theory suggests that REM's sleep function is solely to keep the eye muscles toned up, to do this, about once every 90 minutes during REM sleep are eyes are given some exercise to keep them in trim. However this of course does not even begin to explain why people who are deprived of sleep suffer such severe side affects.
Some common words found in the essay are:
Peter Tripp, Horne Minard, REM Throughout, Eye Movement, System Maintenance, Electroencephalogram EEG, Gardener Tripp, Sleep Stage, Gulevich Johnson, Theory Oswald, rem sleep, slow wave sleep, peter tripp, restoration theory, wave sleep, slow wave, stage 3, functions sleep, evolutionary theory, stage 4, electrical activity, physiological restoration theory, provide evidence physiological, evidence physiological restoration, sleep rem sleep,
Approximate Word count = 2750
Approximate Pages = 11 (250 words per page double spaced)
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