Evaluate the characteristics of sleep and consider what evidence there is for an understanding of why we sleep. Up until the 1950's the majority of researchers believed that 'sleep' was a resting state that was the exact opposite of being awake. It was not until 1953 that work by Kleitman and Aserinsky produced evidence that this was indeed not the case. Berger (1920) was the first researcher to use an electroencephalogram (EEG) to examine electrical brain activity …showed first 75 words of 1661 total…

…showed last 75 words of 1661 total…the majority of mammals. Even though there is not concluding evidence for the function of sleep there is evidence that shows that cognitive ability is kept at its best by maintaining 'normal' sleep patterns. References  Andreassi. J.L. (1989) Pshychophysiology: Human Behavior and Phisiological Response. Earlbrum: Hove.  Carlson, N.R. (1994) Physiology of behaviour. Allyn &Bacon: Boston.  Kimble, D.P. (1992). Biological Psychology. Harcourt Brace Jovanovich: Fort Worth.  Wickens, A. (2000). Foundations of Boipsychology. Prentice Hall: Harlow, England