A local court of Uttar Pradesh permitted Police to conduct polygraph test on five accused in Unnao case
What is a polygraph test?
- Also called Lie-Detection Test, it is a psycho-biological test to check the veracity of statements on computerized equipment known as a lie-detector or polygraph.
- The polygraph test is based on the theory that a person who is lying to a question will produce a physiological response that is different from those that arises in a normal course.
- Instruments such as cardiographs, pneumographs and sensitive electrodes are used to measure the changes in respiration, blood pressure and pulse.
- Based on the records of psychological response, the truthfulness or falsity is accessed.
Polygraph test measures the following autonomic nervous system activities in the form of graphs:
- Abdominal respiration
- Thoracic respiration
- Galvanic skin resistance (GSR)
- Blood pressure/pulse rate
- Muscular pressure
- Finger pulse
- Skin temperature