EDA Positive Change: A Simple Algorithm for Electrodermal Activity to Measure General Audience Arousal During Media Exposure

Abstract

Skin conductance provides an inexpensive and nonreactive measure of electrodermal activity (EDA) that is widely used as an arousal indicator. When communication research employs real-world audiovisual stimuli, the measurement sensitivity of EDA-based data can become challenging. Measures that are commonly employed to correlate EDA with continuous stimuli (the tonic skin conductance level and the frequency of skin conductance responses) are replicable for stimuli of one minute or longer. This article discusses positive changes in EDA (EPC) as a measure that integrates the frequency of skin conductance responses with their amplitude while reducing processing complexity and error. The use of EDA data from 115 subjects demonstrates that EPC is a more accurate measure of stimulus-induced arousal than the response frequency, the conductance baseline, and average skin conductance. Assets and drawbacks are discussed in the context of theoretical and practical issues.