The differentiation of emotions by means of psychophysiological measures has been only moderately successful so far. A major reason for this dilemma may be the lack of appropriate neurophysiological modeling for the various autonomic nervous system based measures being used in emotion research. The aim of the present article is to provide such a neurophysiological background for electrodermal activity which has been frequently used as an indicator of emotional processes. First, the literature is reviewd with respect to the usability of electrodermal measures as an indicators of emotion. second, the neurophysilogical sources of electrodermal phenomena in general are described. Electrodermal activity has different origins in the central nervous system, a limbic-hypothalamic source that dominates during negative emotions as opposed to a premotor and basal ganglia source being predominantly active during positive emotions. Panksepp's model of four basic emotive systems is adopted for demonstrating subcortical structures and pathways possibly involved in the elicitation of both kinds of electrodermal activity in comparison with cardiovascular in dicators of emotional processes.