Polygraph

Polygraph is an electronic instrument used to administer a lie detector test. A polygraph detects and records changes in a person's pulse, blood pressure, breathing rates, and skin conductivity while a person answers a series of questions.

The efficacy of polygraphs is debated in the scientific community. Supporters of Polygraph claim an 85 - 95% accuracy rate. Critics say there is not enough scientific evidence to say whether it detects lies or not.