<unk>  is a common measure of autonomic nervous system<unk> , with a long history of being used in psychological research. Hugo D. Critchley, Chair of Psychiatry at the Brighton and Sussex Medical School states, "EDA is a sensitive psychophysiological index of changes in autonomic sympathetic arousal that are integrated with emotional and cognitive states." Many biofeedback therapy devices utilize<unk>  as an indicator of the user's stress response with the goal of helping the user to control anxiety.<unk>  is used to assess an individual's neurological status without using traditional, but uncomfortable and expensive, EEG-based monitoring. It has also been used as a proxy of psychological stress.<unk>  has also been studied as a method of pain assessment in premature born infants. Often,<unk>  monitoring is combined with the recording of heart rate, respiratory rate, and blood pressure, because they are all autonomically dependent variables.<unk>  measurement is one component of modern polygraph devices, which are often used as lie detectors. The E-meter used by the Church of Scientology as part of its practice of "auditing" and "security checking", is a custom<unk>  measurement device.
Electrodermal activity
Basal body temperature
Muscle tone
Heart rate variability
Myogenic tone
Vagal tone
Optokinetic response
Basal metabolic rate