The Effect of Stimulus Significance on Skin Conductance Recovery

The relationship between skin conductance (SC) recovery time and stimulus meaning was investigated. Previous research has shown that a strong relationship between prestimulus electrodermal activity (prior activity) and recovery time makes it necessary to control prior activity before the relationship of recovery time and stimulus meaning can be evaluated properly. In this study prior activity was controlled by experimental design. We examined the effects of stimulus meaning on skin conductance recovery time and amplitude in 55 teenage and young adult subjects in a continuous performance paradigm. Tones were presented monaurally to left and right ears. Subjects were required to make a pedal press after any tone in the left or right ear that followed a right‐ear tone. Recovery time was computed for left‐ear and right‐ear tones not requiring a press because they had been preceded by a left‐ear tone. SC recovery was longer for signal (right‐ear) than for nonsignal (left‐ear) tones with the effects of prior SC activity and amplitude removed. These findings replicate those of a pilot study (Janes, 1982). We conclude that stimulus significance can affect SC recovery time and that in this paradigm differences in prior SC activity cannot account for the recovery time differences observed.