Polygraph test or the lie detector is widely used in the legal proceedings. It is a helpful device in knowing whether the person is telling the truth or not. It is a very simple and basic device that determines about the person through various health symptoms whether he/she is lying or not.
The polygraph machine monitors the levels of several bodily functions such as pulse rate, heart activities, blood pressure and perspiration.
The person judging the tests looks at the test results that are provided by the subject as well as examines the bodily functions to the determine if the subject is engage in any deceptive behaviors.
The machine is actually an analog machine that starts scribbling the lines like a graph automatically when the one of it is attached to the subject.
There is no doubt about it that the lie detector is an amazing device to detect the wrong behavior of the subject through its bodily symptoms. It is a fact that very few people can control their psychological functions. The polygraph test runs some tests that are designed in a way to measure the reactions of the person whether he/she is telling a lie.
On the other hand, there are people who feel stressed under the concealed condition such as interrogations, legal proceedings etc. There is no reliable way to determine the subject’s stress generated by the lie detector tests and the stress generated by the particular lie. Site here http://www.lie-detector.info provides some useful information on lie detector and tests that are done to know the truth.
In the absence of the confession, the lie detector can easily determine if the person is lying. Even the innocent people feel stressed when they are cross-examined, but there are ways to determine this problem. The questions asked to the subject are immaculately calibrated. The operator gets around to the questions and with the series of replies it makes the task easier for them to determine.