How does a Polygraph Test Happen?

Polygraph tests are not things to make fun of. Lie detector testing is the process of verifying the truthfulness of statements made by persons of interest. These statements are often part of an investigation and it is important that lie detector tests establish the truth behind them. Device Components A typical polygraph test machine has three major components, namely the blood pressure cuff, the pneumographs, and the galvanometers. Blood pressure cuffs are attached around the upper arm of an examinee. It covers the branchial artery and provides a continuous tracing of the person’s cardiovascular activity such as his heart rate, blood pressure, and blood volume. Pneumographs are the two rubber tubes fastened around the person’s chest and abdominal areas. These tubes are used to monitor his respiratory activity during the test. Galvanometers are the two protruding electrodes attached to the client’s fingers. These components are used to obtain a reading

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All About the Polygraph Exams

Polygraph tests are vital to various departments and institutions because of their capability to prove the innocence – or guilt –of an individual. The results may not be acceptable evidence in court, but they can turn tables and influence people. It captures various physiological activities such as the following: Blood Pressure The heart rate or the blood pressure is measured through a cardio-sphygmograph cuff on the upper arm of the examinee. A length of rubber tubing is attached to the cuff and runs to the polygraph machine. If a digital polygraph is used, the signals obtained are converted to electrical signals. Respiratory Rate Two air-filled rubber tubes, called pneumographs, are placed around the examinee’s chest and abdomen. Displacement of air takes place inside the tubes as muscles of chest or abdomen expand. Electro-dermal Activity This measures the amount of sweat that appears on your fingertips. Science shows that the fingertips

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Uses and Benefits of Lie Detector Tests

Lie detector tests are often portrayed in film and television as a method by which truth is extracted from the person taking the witness stand. In these shows, the wires attached to the perpetrator’s body is also connected to a machine, which etches a couple of lines onto a piece of paper. A qualified professional would then determine whether the person is telling the truth or not. To the untrained individual, it all seems like a figment of one’s imagination. However, there is a science to it. Psychology reveals that a person experiences physiological responses that varies depending on the situation he’s in. Experts believed that when a person tells a lie, he experiences internal changes, which is often unseen by the naked eye. Thus, they have devised a method which is able to determine whether a person is experiencing these internal responses. They were able to come up with

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All about Lie Detector Tests

The polygraph test, also known as lie detector test, is a method by which a person’s physiological indices are measured and recorded while being asked a series of questions. These indices include, but are not limited to, blood pressure, pulse, respiration, and skin conductivity. A person is believed to have varying physiological responses depending on his thoughts. This is where lie detector tests are anchored. It is believed that these responses will be able to reflect the truth or falsity of a person’s statement. Brief History Humanity’s quest for wanting to know the truth dates back to the Middle Ages. Back then, torture was used to elicit information from a person’s lips. Luckily, these are no longer sanctioned in these modern times. Fast forward to 1895, a device invented by Cesare Lombroso was used to aid police cases in determining a person’s blood pressure. Later on in 1904, Vittorio Benussi

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Uncovering the Truth about Lie Detector Tests

In a dark room with several lights glowing, there sat a tall, lanky guy. There were several wires hooked to him while two men in uniform hawked around him. ‘Did you steal the money inside the vault?’ sternly asked the taller guy in uniform. The tall, lanky guy sweated like a pig as he whimpered and said no. The other guy nodded his head as he looked at a machine scribbling lines and letters on paper. This is how a polygraph test is usually depicted in movies and crime dramas. But this dark room scenario is far from reality. A lie detector test is done in a clean and well-lit room. The polygraph technician is seated in a table facing the machine and a computer. The apparatus is hooked on to the examinee. The examiner politely asks the questions. As depicted in the scenes above, a polygraph is an apparatus

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A Closer Look at the Lie Detector Test

Who hasn’t watched a crime movie or drama without seeing a polygraph? The lie detector test and the polygraph machine have become all too familiar in today’s pop culture. They are no longer just used in criminal investigations but also in movies, dramas, and even game shows. A lie detector test, also known as a polygraph, is a device used to measure, detect, and record physiological indicators such as skin conductivity, pressure, respiration, and pulse while a person is subjected to several questions prepared beforehand. It was invented by a University of California-Berkeley medical student John Augustus Larson and a Berkley police officer in 1921. The Scientific Basis for Polygraph According to a research conducted by Raymond Nelson in 2015, there is evidence to prove the validity of polygraph tests in terms of screening and diagnostic contexts. Nelson furthermore asserted that polygraph tests combine physiological responses and response differences depending

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How reliable are the lie detectors?

That question is almost inevitable while one writes about polygraphs. While some claimed that a certain percentage of those who failed the lie detection test actually confessed to those crimes subsequently, statistics have shown that their use can be relied on. Lie detectors have proved to be about 80 to 99% effective according to recent studies. Owing to the consistency in the results, they have proved to be reliable and that can be validated. Since they are based on the fact that the stress levels in an individual escalate when they are giving lies, critics argue that one may be coached on how to overcome these stress levels. But let’s face it; you cannot control your brain activity in such moments, can you? That’s just human nature! Just like one doctor cannot look at the x-ray and see a problem, while a more experienced one will see, so it goes

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