title: Comparison between the AC and DC measurement of electrodermal activity.
abstract: Recording electrodermal activity is a well-accepted physiological measurement for clinical approaches and research. Historically, applying a DC (direct current) signal to the skin to measure the conductance is the most common practice for exogenous recordings. However, this method can be subject to error due to electrode polarization even with "nonpolarizing" electrodes-a problem that can be eliminated with alternating current (AC) methodology. For that reason, Boucsein et al. () called for research demonstrating an AC method that is validated by comparison to standard DC methodology. Additionally, the complex structure of human skin has electrical properties that include both resistance and capacitance, and AC recording enables the measurement of skin susceptance (associated with current flow through capacitors). Finally, AC recording permits the simultaneous recording of the endogenous skin potential. In this paper, the results from a direct comparison between both methods are presented, which has not been reported previously. The results demonstrated excellent agreement between a 20 Hz AC method and a standard DC method, supporting the validity of the AC recording methodology employed. The results also showed that an applied voltage of 0.2 V is sufficient for DC recordings.
authors.affiliation: Department of Physics, University of Oslo, Oslo, Norway.
authors.forename: Oliver
authors.initials: O
authors.lastname: Pabst
authors.affiliation: Department of Clinical and Biomedical Engineering, Oslo University Hospital HF, Oslo, Norway.
authors.forename: Christian
authors.initials: C
authors.lastname: Tronstad
authors.affiliation: Department of Physics, University of Oslo, Oslo, Norway.|Department of Clinical and Biomedical Engineering, Oslo University Hospital HF, Oslo, Norway.
authors.forename: Sverre
authors.initials: S
authors.lastname: Grimnes
authors.affiliation: Department of Psychological & Brain Sciences, University of Iowa, Iowa City, Iowa, USA.
authors.forename: Don
authors.initials: D
authors.lastname: Fowles
authors.affiliation: Department of Physics, University of Oslo, Oslo, Norway.|Department of Clinical and Biomedical Engineering, Oslo University Hospital HF, Oslo, Norway.
authors.forename: Ørjan G
authors.initials: ØG
authors.lastname: Martinsen
mesh_terms: D000328:Adult; D025802:Electric Capacitance; D017097:Electric Impedance; D004566:Electrodes; D005260:Female; D005712:Galvanic Skin Response; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Bioimpedance; Electrodermal activity (EDA); Exogenous; Method comparison; Skin conductance; Skin potential