What is holography test ? .
A polygraph, commonly known as lie detector, is a device used to detect lies by measuring several physiological variables of the person being questioned. While taking a polygraph test, a person gets four to SIX sensors attached to his/her body. The poly- graph machine 'records multiple (hence “poly”) signals from the sensors on a single strip of moving paper (“graph”). The sensors usually record the person’s blood pressure, heart rate, respiration and ' perspiration rate While he is asked a series of questions. The main principle behind this test is based on the ancient hypothesis of nervousness while telling a lie.
