The polygraph has been around since the early 1920's. Critics of the polygraph like to argue issues such as accuracy and admissibility; however, nearly a century later the polygraph is still in use amongst government agencies all over the world. The polygraph measures physiological changes that occur in the human body when stimulus is introduced in the form of a question. The polygraph constantly measures these physiological changes that occur during an examination. Utilizing the autonomic nervous system, these changes can often be significant in determining the veracity of an examinees statements.