I think polygraph does work, I mean, the method. When a person lies, or when someone is sensitive about any topic, for example, talking about his love in front of several people, their physiological indices such as respiration or heart beat or pulse etc shows activity. There is also scientific evidence about activity in the brain when a ‘sensitive’ topic is discussed about the person in question. Therefore, I think that during polygraph, a person’s physiological indices can definitely be measured and recorded.