Polygraph

Device purported to detect lies

A polygraph, often incorrectly referred to as a lie detector, is a device that measures and records several clinical biomarkers, such as blood pressure, pulse, respiratory rate, and skin conductivity, and it is used while a person answers a series of questions to purportedly detect lies. Polygraphic assessments rely on the discredited assumption that some physiological mechanisms or functional state, and their variations thereof, could reliably account for psychophysiological phenomena supposedly invoked by (the act of) lying, though polygraphy is considered pseudoscience by the scientific community. The belief underpinning the use of the polygraph is that deceptive answers will produce physiological responses that can be differentiated from those associated with non-deceptive answers; however, there are no specific physiological reactions associated with lying, making it difficult to identify factors that separate those who are lying from those who are telling the truth.

From Wikipedia, under CC BY-SA. More on occurri.