Galvanic skin response (GSR), also known as electrodermal activity (EDA), is a physiological process in which the electrical conductivity of the skin varies due to sweat gland activity. This activity is closely linked to the autonomic nervous system, which responds to emotional states, stress, arousal or cognitive load. During strong emotional reactions or stress, sweat production increases, which leads to increased electrical conductivity of the skin.

In marketing, GSR is used as a method for measuring consumer reactions to various stimuli, such as advertising, product packaging or brand messages. The idea is that an increased GSR indicates positive or negative emotional reactions and engagement. Analysing GSR can help marketers to better understand how customers react to certain marketing elements and how they can optimise their strategies to achieve a stronger emotional connection and ultimately more sales.