Courtesy of the American Psychiatric Glossary, 7th Edition:
(GSR) The change in the electrical resistance of the skin following stimulation; an easily measured variable widely used in experimental studies.
The galvanic skin response, sometimes referred to as the electrodermal response (EDR), measures changes in the electrical conductivity of the skin, usually across fingers or the palm, resulting from increased sweat gland activity when presented with an emotionally arousing stimulus.
You’ll find GSR sensors in biofeedback equipment used to train people to relax; in polygraph equipment used to support interrogations; and in psychology experiments which deal with emotional state and arousal of the cerebral cortex.
