Strength/duration relationships for electrocutaneous sensitivity: Stimulation by capacitive discharges

Abstract

Methods of stimulating the skin by capacitive electrical discharges are described and properties of the stimulus waveforms are discussed. A neural excitation model is invoked to account for electrocutaneous sensitivity. The model gives a good account of threshold data from several experiments in which the methods of stimulation are compared. Sensitivity is shown to be charge-dependent for stimuli that are brief relative to the exponential time constant of the neural membrane model. Systematic departures from charge-dependence occur when the stimulus discharge time constant is made to exceed a depolarization time constant: these departures follow a strength]duration relationship predicted by the model. © 1984 Psychonomic Society, Inc.