Psychophysiologic assessment of erectile response and its suppression as afunction of stimulus media and previous experience with plethysmography

The present study examined college men's (N = 35) differential ability to s uppress sexual arousal as a function of(a) stimulus media (audio-only vs. a udiovisual), (b) experience with the procedure, and (c) novelty of the stim ulus material. Further galvanic skin response (GSR) and finger pulse amplit ude (FPA) were examined as possible methods of detecting attempts to suppre ss sexual arousal. In general, participants were able to reduce substantial ly their plethysmographically-assessed erectile response, and these efforts were not significantly detectable through GSR or FPA measurement. Further neither experience nor stimulus novelty were found to have a significant ef fect on arousal or the ability to suppress it. Participants were, however l ess aroused in response to audio-only presentations than audiovisual presen tations once they were experienced with the procedure. This effect, in comb ination with participants' considerable ability to suppress, could result i n more false negative conclusions being drawn when audio-only versus audiov isual stimulation, is used in sex-offender plethysmography.