Narco Analysis Test:
A person is able to lie by using his imagination. In the Narco Analysis Test, the subject’s imagination is neutralised by making him semi-conscious. In this state, it becomes difficult for him to lie and his answers would be restricted to facts he is already aware of.
Experts inject a subject with Sodium Pentothal or Sodium Amytal. The dose is dependent on the person’s sex, age, health and physical condition. A wrong dose can result in a person going into a coma, or even death.
The subject is not in a position to speak up on his own but can answer specific but simple questions. The answers are believed to be spontaneous as a semi-conscious person is unable to manipulate the answers.
When the brain recognises a person or a sound, it generates a particular type of electric wave, which is called a P300.
Sensors are attached to the head of a person undergoing a P300 test and the subject is seated before a computer monitor. He is then shown certain images or made to hear certain sounds. The sensors monitor electrical activity in the brain and register P300 waves, which are generated only if the subject has some connection with the stimulus, in this case pictures or sounds.
The subject is not asked any question.
These test are used by investigators to cross check their findings, determine if a suspect is telling the truth or make him reveal facts pertaining to a case.