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Polygraph, the honesty test
Akhbar Satar | 17 Feb 2017 00:30
Akhbar Satar is a criminologist and certified fraud examiner. Comments: editor@focusmalaysia.my
THE polygraph or lie detector works by detecting changes in a person’s bodily functions. Emotional stress can stimulate blood pressure, pulse rate, respiratory system and skin when a person lies under questioning. The test is done in three phases. During the first phase, an examinee is informed of his/her rights, and if he/she agrees signs a consent form. The examiner then discusses with the examinee specific issues which are the subject matter of the questions that will be asked during the test. Once both parties agree, the questions will be formulated during this stage. The examiner will also assess the subject’s emotional and physiological suitability to take the test. During the second phase, the polygraph instrument is connected to the computer, while several wires are connected to various parts of the subject’s body, including fingers, chest and arm The examiner administers at least three separate tests, each lasting less than five minutes where a subject’s physiological data or responses are recorded onto the polygraph charts as the subject answers a set of questions reviewed earlier. Based on psycho-physiological principle, when the examinee hears a question which he or she intends to lie, the brain interprets and triggers automatic and uncontrollable physiological changes by the polygraph.

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