The lie detector examines memory and records psychophysiological reactions when presented with relevant stimuli. The level of emotionality and the type of nervous system of the examinee do not affect the result because even in a highly emotional person, reactions indicative of deception will not be detected if there are no traces of the requested event in their memory. The overall level of truthful answers from an emotional person may be high, but their reactions do not contain informative signs of attempting to conceal or distort information provided during the polygraph examination.