In an attempt to demystify the subject it should be made clear that there is no known instrument which can actually detect lies.
If the label “lie detector” must be used, it is best attached to the examiner who interprets the physiological by-products of a tested person’s emotional responses, and by using various techniques in conducting the polygraph examination, is able to offer an opinion of truth or deception.
The test itself is a series of questions asked of the subject and the simultaneous recording by the polygraph instrument of the subject’s bodily changes in response to these questions.
The polygraph examination is best described as a scientific diagnosis of the psychological, physical and emotional changes triggered when a subject is examined.