Galvanic Skin Response (GSR) refers to the change in electrical conductivity of the skin, which varies with moisture levels. This response is often measured using electrodes placed on the skin, typically on the fingers or palms. When a person experiences emotional arousal, such as stress or excitement, their sweat glands become more active, leading to increased skin conductivity. GSR is commonly used in psychological research and lie detection, as it can indicate emotional responses that may not be consciously recognized. Devices that measure GSR are often part of polygraph tests, which assess physiological changes associated with truthfulness or deception.