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Discuss two theories of sleep.

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Introduction

Discuss two theories of sleep. One theory of sleep is that it is needed for physical and psychological restoration and repair. Oswald 1966 said that sleep was needed for the restoration of cells and to restore energy levels. If Oswald's theory were true then you would expect sleep deprivation to have serious consequences, as the body would be unable to repair its self. You would also expect more sleep to be needed if more physical energy had been used. Oswald's study is supported by Rechtschaffen study on rat, as all the rats died after 33 days of sleep deprivation. Jouvet's study also supports this theory as the cats died when deprived of REM sleep. Although there is also evidence that goes against Oswald's theory, for example Randy Gardener went for 264 hours with out sleep, he suffered very few side effects and only needed an extra 7 hours of sleep to recover from his sleep deprivation. ...read more.

Middle

Although protein synthesis is said to take place during SWS and REM sleep protein is need and protein only lasts around 4 hours in the body. Sleep is also said to help physical restoration Hartmann 1973 found that people generally needed to sleep more during times of stress. It is also found that insomniacs tend to be very anxious, however it cannot be said that insomnia causes the anxiousness or the anxiousness causes the insomnia. Another theory of sleep is the evolutionary theory. This is based on the idea that all animals sleep, but they sleep different amounts and at different times, and go into different stages of sleep. The reason for this is said to be because sleep has evolved to fit the ecological niche to which the animal belongs. Meddis 1979 said that sleep has evolved to keep animals safe from predators, and to suit their needs and method of finding food. ...read more.

Conclusion

is used to keep the brain warm, as reptiles are cold blooded they don't need to do this so they have evolved to not dream. This theory does not explain why some animals don't fit the pattern, for example the giant sloth is large a slow yet sleeps for 20 hours a day. This theory also doesn't explain why humans still require so much sleep when it would clearly be and advantage to humans to evolve to need less sleep. There has not been much research to back up this theory as it is hard to back up any evolutionary theory, although it is not too far fetched to believe that animals evolving in this way, was to protect them from pray and to conserve energy. Horne 1988 suggested that different animals may have different uses for sleep and that there may not be a universal function of sleep that fits all animals. Faye Johnson 13.6 ...read more.

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