Polygraph

A polygraph (commonly and inaccurately referred to as a "lie detector") is a device which measures and records several physiological variables such as blood pressure, heart rate, respiration and skin conductivity while a series of questions are being asked, in an attempt to detect lies. The above measurements are posited to be indicators of anxiety that accompanies the telling of lies. Thus, measured anxiety is equated with telling untruths. However, if the subject exhibits anxiety for other reasons, a measured response can result in unreliable conclusions.
A polygraph test is also known as a psychophysiological detection of deception (PDD) examination. The original polygraph was invented by John A. Larson. 
== Appearances ==
== References ==
* passed a polygraph test in 1990 when confessing to thirteen murders, even though there had been sixteen. ( "Paper Hearts")
== External links ==
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Category:Technology