Editing Affective computing (section)

====Galvanic skin response====
{{Main|Galvanic skin response}}

Galvanic skin response (GSR) is an outdated term for a more general phenomenon known as [[Electrodermal activity]] or EDA.  EDA is a general phenomena whereby the skin's electrical properties change.  The skin is innervated by the [sympathetic nervous system], so measuring its resistance or conductance provides a way to quantify small changes in the sympathetic branch of the autonomic nervous system.  As the sweat glands are activated, even before the skin feels sweaty, the level of the EDA can be captured (usually using conductance) and used to discern small changes in autonomic arousal.  The more aroused a subject is, the greater the skin conductance tends to be.<ref name="Picard, Rosalind 1998"/>

Skin conductance is often measured using two small [[silver-silver chloride]] electrodes placed somewhere on the skin and applying a small voltage between them. To maximize comfort and reduce irritation the electrodes can be placed on the wrist, legs, or feet, which leaves the hands fully free for daily activity.