The Galvanic Skin Response (GSR, also electrodermal activity EDA) indicates the electrical conductivity of the skin. Due to the increased perspiration of the skin the skin resistance decreases with increasing emotional activity. The skin conductivity was therefore often used in the past as a simple measure in lie detection tests. Unfortunately the skin conductivity is not directly related to the degree of emotional arousal but follows a more complex mathematical curve in response to a stimulus. Thus measured over time it first must be converted by a complex pre-processing before it is helpful for further quantitative analysis.

Significance for the emotional intensity: high
Informative value on the kind of emotion: low
Informative value on the mental workload: low
Effort: easy to measure via two electrodes, for example on the palm