Frequently Asked Questions
What does a polygraph record?
A polygraph test records physiological responses whilst the examinee answers a series of questions.
Polygraph techniques are derived directly from basic scientific principles and research in psychology and human psychophysiology. Physiological measurement techniques for the detection of deception have been developed and subjected to scientific evaluation for almost 100 years.
The most commonly used polygraph tests are based on widely accepted scientific principles. It is well established that certain stimuli, such as questions to which a person is lying during a polygraph test, produce involuntary changes that are controlled by the autonomic (sympathetic & parasympathetic) nervous system. These reactions include increased skin conductance (palmar sweating), increased blood pressure and decreased respiratory activity.