Lie detector (polygraph) how it works

[Yelena]

[MEDIA = youtube] 9ryCo41X1wk [/MEDIA] The lie detector (polygraph) is the latest computer to which sensors, a sensor unit, and a video camera are connected. The whole range of devices fits easily in a small bag. Previously, a polygraph was examined by military and criminals. At the present time, such a test can be done by everyone. This occurs when applying for a job, in government bodies during promotion, in legal proceedings and in other areas and organizations. How does this device work? Sensors measure the speed and depth of breathing. A skin-galvanic sensor, dressed on a ring finger, monitors perspiration, on other fingers, devices record a pulse, photocells monitor the state of blood vessels. Pressure tracks the cuffs, dressed on the arm, when a person is lying, he jumps. The subject sits on two sensors that record his motor activity. So many devices are hard to resist. The test person answers questions, the specialist receives information on how the body responds to a deliberate lie. When the patient is lying, the respiratory rate and sweating do not change, but the vessels are strongly compressed, breathing becomes rare and superficial. After the polygraph knows all the individual reactions of a person, testing begins. Questions are asked each 3 times, between them there is a pause of 20-30 seconds. By gestures, facial expressions, a specialist can also catch a hoax, for the reliability of the process, they record it on a video camera, so that they can be watched frame by frame. Analysis of the data is performed after three hours of testing. Only an experienced operator can describe the real situation. Such specialists have been trained for more than one year, and the probability of a miss is almost zero.