Electrodermal activity (EDA) is a measurement of the electrical conductance of the skin, which reflects the activity of the sweat glands and sympathetic nervous system. It is commonly used as a physiological marker of emotional arousal and stress. EDA can be measured using electrodes placed on the skin surface, typically on the fingers or palms. Changes in EDA are believed to be associated with emotional responses, cognitive processes, and autonomic nervous system activity. Researchers use EDA to study a variety of topics, including emotion regulation, stress response, and mental health.