These phenomena were further studied by numerous other researchers during the 19th and 20th centuries. In 1881, Hermann repeated this voluntary movement experiment, noting that areas with stronger sweating response showed a higher magnitude electrical current, providing a link between sweat glands and electrodermal phenomena. DuBois-Reymond observed a current flowing from a resting limb to a limb contracted by the participant, and attributed this to muscular action potentials. This is an important consideration as EDA responses are often but one of many psychophysical phenomena occurring in response to activation of the autonomic nervous system.ĮDA measurement has a long history, dating back to experiments conducted by DuBois-Reymond in Germany in the mid-1800s, in which individuals placed hands or feet into a zinc sulphate (ZnSO 4) solution. EDA signals tend to spike when a person is startled, stressed, or experiencing anxiety.ĮDA measurements are often combined with other physiological measurements such as blood pressure, heart rate, and respiration rate. It should be noted that there is is not absolute agreement on exactly what EDA measures psychophysiologically, and it is best to consider EDA measurements as indicators of general arousal, rather than indications of specific emotional states. EDA is commonly used in psychophysiological studies to measure activations of the sympathetic nervous system, emotional arousal, and cognitive phenomena such as stress and cognitive load. It has the advantages of being convenient and economical, and can be applied in both laboratory and real-world settings. The signal is sensitive to changes in mental state and cognitive processes. This article will favour the use of the term EDA.ĮDA is an easy-to-measure and generally reliable measurement commonly used in psychophysiological studies.
EDA is now the standard umbrella term for what has historically been known as galvanic skin response (GSR), electrodermal response (EDR), psychogalvanic reflex (PGR), skin conductance response (SCR), sympathetic skin response (SSR), skin conductance level (SCL), and skin conductance (SC). Electrodermal activity (EDA) is a type of biosignal (electrical signal produced in the body) which refers to the variable electrical characteristics of the skin.