Autonomic response to auditory, visual and imagined stimuli in a systematic desensitization context

Abstract

Forty subjects were randomly assigned to one of two procedures, a systematic desensitization analogue (SD) and a non-relaxation control (NRC). All subjects experienced a fear-provoking stimulus (albino rat) in three different forms: auditory (verbal description), visual (slides) and visual imagery. Autonomic nervous system responses to the stimuli were monitored. No differences between the SD and the NRC groups were found with respect to autonomic response (electrodermal) to the feared stimuli and with respect to decrement in autonomic response (electrodermal and cardiovascular) over trials. Imagined stimuli elicited greater electrodermal and cardiovascular response than did visual and auditory stimuli, but there were no consistent differences among stimulus modalities in degree of autonomic response decrement over trials. It was found, however, that imagined and visual stimuli resulted in statistically significant autonomic response decrements notably more often than auditory stimuli, but not more often than one another. The results led to the conclusion that, in terms of the autonomic components of the fear response, external visual stimuli could be justifiably used in place of visual imagery in systematic desensitization.