A continuous measure of phasic electrodermal activity

TLDR

Electrodermal activity consists of overlapping skin conductance responses, making classic trough‑to‑peak analysis difficult. The authors propose a deconvolution method that separates skin conductance data into continuous tonic and phasic components. The deconvolution yields a phasic signal with a zero baseline and compact impulses (<2 s) for overlapping responses, and its time integration serves as a simple indicator of event‑related sympathetic activity. The method’s quality and advantages over prior decomposition techniques are demonstrated in experiments with short interstimulus intervals and in simulation studies, highlighting its improved performance.

Abstract

Electrodermal activity is characterized by the superposition of what appear to be single distinct skin conductance responses (SCRs). Classic trough-to-peak analysis of these responses is impeded by their apparent superposition. A deconvolution approach is proposed, which separates SC data into continuous signals of tonic and phasic activity. The resulting phasic activity shows a zero baseline, and overlapping SCRs are represented by predominantly distinct, compact impulses showing an average duration of less than 2 s. A time integration of the continuous measure of phasic activity is proposed as a straightforward indicator of event-related sympathetic activity. The quality and benefit of the proposed measure is demonstrated in an experiment with short interstimulus intervals as well as by means of a simulation study. The advances compared to previous decomposition methods are discussed.