“A polygraph machine doesn’t detect lies. It detects physiological changes that occur in a person’s body in response to a stimulus, the stimulus being a question posed by the polygraph examiner. Whether or not the anxiety associated with those changes is indicative of deception is an open question that must be answered by the analytical and human interaction skills of the polygraph examiner. The pens on a polygraph chart record four physiological responses to the stimulus. There are two respiratory tracings, one cardiovascular activity tracing, and one galvanic skin response tracing, which records changes in skin moisture.”