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
However the research is inconclusive and still continues. For instance, he began to mistake objects for people. Horne and Minard also provide evidence against the physiological restoration theory by showing that participants who were engaged in various physical activities, although went to sleep faster; they found no increase in the amount of time actually spent asleep. They naturally occur at a rate of one per minute. Some researchers believe that sleep spindles and K complexes help us disconnect from the outside world (noises, etc). 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). It was noted that Randy Gardener recovered almost 70% of stage 4 sleep and 50% of REM sleep, which suggests that these stages of sleep are of special importance. 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. In laboratory experiments, it has been shown that rats will spend longer in the REM stage of sleep after having been trained in a maze. He also felt that some people were labelling him as stupid because of his impaired cognitive abilities. These two waves (alpha and beta) represent the irregular firing pattern of large areas of the brain. However this of course does not even begin to explain why people who are deprived of sleep suffer such severe side affects. Through EEG readings Sleep has been separated into five stages. Support for this theory comes from Kales et al 1974, who showed that insomniacs suffer far more psychological problems than healthy people. without any mental arousal, the EEG records a waveform called alpha waves or alpha activity, slower than beta waves.
Common topics in this essay:
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Horne Minard,
REM Throughout,
Eye Movement,
System Maintenance,
Electroencephalogram EEG,
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Sleep Stage,
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rem sleep,
slow wave sleep,
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restoration theory,
wave sleep,
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stage 3,
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evolutionary theory,
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evidence physiological restoration,
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Acceptance Essays
