Sleep deprivation is a common occurrence in modern culture. Every day there seems to be twice as much work and half as much time to complete it in. This results in either extended periods of wakefulness or a decrease in sleep over an extended period of time. While some people may like to believe that they can train their bodies to not require as much sleep as they need, this belief is false. Sleep, by definition, is the natural periodic suspension of voluntary bodily functions and complete or partial suspension of consciousness, during which the powers of the body are restored (Ratcliff & Van Dongen, 2009). Only in the last century have the psychological and scientific areas of study began to investigate and explore the nature, purpose, and properties of sleep. The purpose of this essay is to analyze the value and effect of sleep deprivation on cognition. The majority of articles describe partial sleep deprivation as having negative effects on cognitive, behavioural, physiological, and emotional measures. From this information, it is derived that various cognitive abilities will affect productivity and performance. Therefore, it is hypothesized that sleep deprivation affects cognitive, behavioural, physiological and psychological measures because it increases and worsens stress, impairs cognitive function and emotional stability.…