The government has no proposal to seek a review of a Supreme Court judgment banning forced narco-analysis, polygraph and brain-mapping tests on accused or suspects, the Lok Sabha was informed Wednesday.
Replying to a question, Home Minister P. Chidambaram said that there is no proposal to seek a review of the judgment that narco-analysis, polygraph and brain-mapping tests cannot be conducted on anyone, either an accused or a suspect, without his or her consent.
Narco-analysis is an invasive test and should not be administered while polygraph, by and large, is a non-invasive test, Chidambaram told the house.
‘Personally speaking polygraph by and large is a non-invasive test but narco-analysis is an invasive test and it should not be administered, in my opinion,’ he said.
The apex court ruling May 5 said no accused can be forced to undergo these tests as this would violate his or her rights under Article 20(3) of the constitution that says no accused can be compelled to be a witness against himself.
Narco-analysis, polygraph and brain-mapping tests are often used to help investigations into crimes. All three are different from each other but are all aimed at collecting information.
Narco-analysis is a controlled administration of intravenous hypnotic medications called truth drugs on a suspect to procure vital information.
A polygraph, popularly known as a lie-detector, measures and records physiological indices such as blood pressure, pulse, respiration and breathing rhythms and skin conductivity while a suspect is quizzed.
Deceptive answers are said to produce physiological responses that can be differentiated from those associated with non-deceptive answers.
Brain-mapping is a comprehensive analysis of brainwave frequency bandwidths. In this, forensic experts apply unique neuroscience techniques to find if a suspect’s brain recognises things from a crime scene that an innocent person’s brain will have no knowledge of.
In brain-mapping, sensors are attached to the suspect’s head and he or she is made to sit in front of a computer screen. The suspect is then made to see images or hear sounds.
The sensors monitor electrical activity in the brain and register certain waves which are generated only if the suspect has any connection with the stimulus (image or sound).