lie detector


lie detector
a polygraph used to determine changes in certain body activities, as blood pressure, pulse, breathing, and perspiration, the results of which may be interpreted to indicate the truth or falsity of a person's answers under questioning.
[1905-10, Amer.]

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Instrument for recording physiological phenomena (including blood pressure, pulse rate, and respiration) of a human subject as he or she answers questions asked by an operator.

These data (recorded as graphs) are used as the basis for judging whether the subject is lying. The phenomena usually chosen for recording are those not easily controlled voluntarily. The types of questions asked, their wording, and the mode of presentation have a tremendous effect on the results and their reliability. Used in police interrogation and investigation since 1924, the lie detector is still controversial among psychologists and not always accepted as evidence in courts.

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also called  Polygraph,  

      instrument for recording physiological phenomena such as blood pressure, pulse rate, and respiration of a human subject as he answers questions put to him by an operator; these data are then used as the basis for making a judgment as to whether or not the subject is lying. Used in police interrogation and investigation since 1924, the lie detector is still controversial among psychologists and not always judicially acceptable.

      Physiological phenomena usually chosen for recording are those not greatly subject to voluntary control. A pneumograph tube is fastened around the subject's chest, and a blood pressure–pulse cuff is strapped around the arm. Pens record impulses on moving graph paper driven by a small electric motor.

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Universalium. 2010.

Look at other dictionaries:

  • lie detector — lie detectors N COUNT: oft N n A lie detector is an electronic machine used mainly by the police to find out whether a suspect is telling the truth. ...the results of a lie detector test which he said proved his client s innocence. Syn: polygraph …   English dictionary

  • lie detector — detector / lai di tektə/, it. / lai de tɛktɔr/ locuz. ingl. (propr. rivelatore di bugie ), usata in ital. come s.m. [strumento che registra le modificazioni del respiro, del polso e della pressione arteriosa allo scopo di obiettivare le reazioni… …   Enciclopedia Italiana

  • lie detector — lie de·tec·tor n: an instrument for detecting physiological evidence of the tension that accompanies lying compare polygraph Merriam Webster’s Dictionary of Law. Merriam Webster. 1996 …   Law dictionary

  • lie detector — lie de·tec·tor loc.s.m.inv. ES ingl. {{wmetafile0}} macchina della verità {{line}} {{/line}} DATA: 1950. ETIMO: ingl. lie detector propr. rivelatore di bugie …   Dizionario italiano

  • lie detector — lie de.tector n a piece of equipment used especially by the police to check whether someone is lying, by measuring sudden changes in their heart rate ▪ He was asked to take a lie detector test …   Dictionary of contemporary English

  • lie detector — ► NOUN ▪ an instrument for determining whether a person is telling the truth by testing for physiological changes considered to be associated with lying …   English terms dictionary

  • lie detector — ☆ lie detector n. a polygraph used on persons suspected of lying: it records certain bodily changes assumed to occur when the subject lies in answering questions …   English World dictionary

  • lie detector — UK / US noun [countable] Word forms lie detector : singular lie detector plural lie detectors a piece of equipment used for checking whether someone is telling the truth …   English dictionary

  • lie detector — SYN: polygraph (2). * * * lie detector lī di .tek tər n a polygraph for detecting physiological evidence (as change in heart rate) of the tension that accompanies lying * * * polygraph …   Medical dictionary

  • lie detector — noun Lie detector is used before these nouns: ↑test …   Collocations dictionary


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