Introduction Polygraph (lie detector Tool) works in an Interview
I caught, so to speak a lie detector said that if people demonstrated Testing is a lie. While the mouth can lie, but the rate of breathing, sweating, heart rate, blood pressure can not fool the lie detector (polygraph).
The lie detector is not easy. Although there are some signs when someone is lying. But with a lie detector or polygraph, an expert is not going to lie to avoid. How does the instrument?
Each person has lied different style. Many reasons are presented when lying, but generally a person lying as a defense mechanism to avoid problems.
A tool specially created to detect lies was eventually created. The instrument was given the name of polygraph first created by James Mackenzie in 1902. Then in 1921, created the modern version of John Larson, who was once a student at the University of California.
Polygraph widely used by police or the FBI for interrogation and investigation of a case. However, this tool is still reaping the controversy, especially among psychologists. They say there is no specific rule that can detect lies.
Lie Detector is a way of working with the entire record and record at the same time the body's response when asked a question. In short, when someone is lying, saying the issue will result in psychological reactions in the body of work that affect organs like the heart, skin, and others.
Through sensors connected to the body part or organ, changes in organ function diketahuilah graph, including graphs of respiration, heart rate, blood pressure, sweating and others. Polygraph tests are generally for 2 hours with accuracy levels up to 90 percent.
A package consists of the tool monitors the polygraph and other digital sensor that is connected to all parts of the body to determine the changes or fluctuations psikologia when someone tells the truth or lie. Here's the procedure works:
1. Someone will be tested by polygraph sitting on the bench. Inside the interrogation room, there were only two people, the examiner (Examiner psychophysiologist) and the test.
2. Some of the sensors connected to cable for polygraph equipment installed in the body of someone who will be tested. Sensors are included as follows:
Pneumograph to detect respiration rate, placed on the chest and abdomen, to work when there is a contraction in the muscles and the air in the tube.
Blood pressure cuff to detect changes in blood pressure and heart rate, which is attached to the upper arm, working with the sound coming from the heart rate or blood flow.
The galvanic skin resistance (GSR) to detect the sweat, especially in the area of the hands, attached to the fingers, works by detecting the amount of sweat that comes out when under stress and lying.
3. Examiners then give someone some questions about a topic, issue or event.
4. Examiners will read the letter and see if there is an abnormal reaction or fluctuate.
5. The fluctuations are readable by the polygraph instrument determines whether a person is lying or dishonest.
Polygraph is used for state security agencies, criminal investigations, the selection process and also a bank employee. Currently, according to Dr. Frank Horvath, a professor of criminology at Michigan State University, there are around 3,000 examiners (Forensic psychophysiologist) in the United States, and 2,000 of them are members of the American Polygraph Association. They are trained in special schools have been accredited by the American Association of Police polygraph.
Although called polygraph lie detector, but actually means it can not detect lies. "It was just the monitor and react to the psychological changes in people who say dishonest. We can not know what it is like a lie," said Dr. Bob Lee, (polygraph polygraph test) and also the executive director Axciton Systems, a manufacturer of polygraph.
