The ohmic perturbation duration, an original temporal index to quantify electrodermal responses

Behav Brain Res. 1995 Feb;67(1):103-7. doi: 10.1016/0166-4328(94)00148-9.


The reactivity of the autonomic nervous system was (D.C.) recorded using six parameters simultaneously. Such a device permitted to describe a new index of skin resistance response (SRR). The ohmic perturbation duration (O.P.D. index) was defined as the period during which the subject is effectively responding to the stimulation. O.P.D. index was easily quantified because the specific part of the response, showing many fluctuations at a low resistance level, can be distinguished from the recovery part without fluctuations or with smaller microevents of different kinds. Moreover, the slope of this fluctuation is identical to that observed just before the stimulation. The comparison between the values of the O.P.D. index and classically used SRR durations enabled us to calculate the identity percentages from five other neurovegetative parameters. Results showed high values for the skin potential (91%) and skin blood flow (82.5%). These values were smaller as far as skin superficial temperature (50.5%), heart (40.8%) and respiratory (46.5%) variations were concerned. Nonetheless these last three percentages were still higher than those usually obtained with the values of the correlation coefficients from different, simultaneously recorded parameters. O.P.D. index comparison with four other classical used temporal indices (recovery time, 1/3, 1/2 and 2/3 of the recovery time) show a high significant concordance in O.P.D. index opposed to aleatory one obtained with these four other durations. Thus, the O.P.D. index could be an appropriate measure of electrodermal response (EDA) allowing any stimulus to be temporarily quantified towards sympathetic activation induced response.

MeSH terms

  • Adult
  • Autonomic Nervous System / physiology*
  • Emotions
  • Evoked Potentials
  • Galvanic Skin Response*
  • Humans
  • Skin Physiological Phenomena*