Recently, the CBI conducted a polygraph test on the main suspect in the Kolkata doctor rape-murder case, to evaluate his credibility during the ongoing investigation.
Polygraph Test
Definition: A polygraph, or lie detector test, is a procedure that measures and records several physiological indicators, including blood pressure, pulse, respiration, and skin conductivity, while a person answers a series of questions.
Basis of the Test: The test operates on the assumption that physiological responses during lying differ from those when a person is telling the truth.
Evaluation of Responses: These are assigned numerical values to determine whether the person is being truthful, deceptive, or uncertain.
Historical Context: The concept of a polygraph-like test was first used in the 19th century by Italian criminologist Cesare Lombroso, who measured changes in blood pressure during interrogations.
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