Contents:
- Medical Video: Polygraph Expert Shows How to Beat a Lie Detector Test
- What is a lie detector?
- How do lie detectors work?
- Then is it effective for the lie detector test results?
Medical Video: Polygraph Expert Shows How to Beat a Lie Detector Test
In the realm of law, investigators often use lie detectors to reveal the real truth. Sometimes, if someone applies for a particular job profession, a lie detector is also needed when the interview takes place. Approximately, how do lie detectors work? And is it effective to find the truth?
What is a lie detector?
Lie detector is a polygraph machine designed with special sensors to detect lies in humans. This tool was originally discovered in early 1902. Along with the development of the times, lie detectors already have many versions that are more modern and more sophisticated.
The lie detector basically works by recording and recording a person's reaction in the form of magnetic waves when he is given a number of questions on an ongoing basis. You will be placed with a number of sensors during the process to detect your vital organs, such as heart rate, breathing, and skin.
Psychological reactions that arise when you say something, whatever it is, will unwittingly affect the workings of the organs. Through sensors attached to your body, investigators can find out whether there are abnormal changes in the three body functions above. The results are then directly printed on a graphic paper. Examination through lie detector generally lasts more than 1.5 hours.
How do lie detectors work?
When you do a test with a lie detector, there are 4 to 6 sensors that will be connected to the body. There are also other digital sensors that are connected throughout the body to find out whether there are psychological changes when someone is lying or just telling the truth. The following is how the lie detector works to detect lies.
First, you are required to sit on a special bench in a certain room. Then, the polygraph machine sensors will be affixed to your body. There are 3 cable sensors commonly used in detecting lies.
- The pneumograph sensor, the point is to detect the beating of the breath that is affixed to the chest and abdomen. This sensor works when there are contractions in the muscles and air in the body.
- Blood Pressure Cuff Sensor, its function is to detect changes in blood pressure and heart rate. This cable sensor is attached to your arm. The way it works is detected by the sound of a heartbeat or blood flow.
- Sensor skin resistance, to see and detect sweat in the hand. This sensor cable is generally also attached to the fingers, so you know how much sweat comes out when you are cornered and lying
Second, the examiner will ask you questions about a topic, issue or case that wants to know the truth. Then, they will read the chart and find out if there is an abnormal reaction or graph that is up and down. After the graph results are read by the examiner, the results of the graph will be used as a determinant, whether you are lying or honest.
Then is it effective for the lie detector test results?
Inspection through lie detector is generally accurate up to 90 percent. But this does not necessarily apply to all cases. Because, this tool only monitors and shows psychological changes when you say something. Physical signs and "strange" signs that often indicate that people are lying, such as stuttering, sweating, or unfocused eye movements are not always indicative of lies. These characteristics may indicate that you are nervous, stressed, or feel uncomfortable in certain conditions. In this case, it becomes the "object" of research. In general, every person has a diverse style of speech, not to mention taking into account the shrewdness of people to cover up lies.
Detecting lies is not an easy task, and even tends not to be done with the naked eye. Lie detector toothere is still controversy among psychologists, because there is no standard of lies that can be measured through physical or non-physical tools.
