Detecting faked penile responses to erotic stimuli

Eighteen men were instructed to fake penile responses to discrete sexual stimuli presented auditorily or visually. The same stimuli were presented a second time following instruction on faking. Sexual responses were monitored using a penile plethysmograph (PPG). Further physiological response measures to detect faking attempts included the Galvanic Skin Response (GSR) and respiration (RESP). Faking attempts were found to be more successful to audio than visual stimuli, especially if the stimuli were relatively weaker. Arousal was much more difficult to fake than suppression. The more intense the efforts to fake, and especially following faking instructions, the more transparent the faking efforts. GSR and RESP added measurably to the detection of faked PPG responses which would have appeared otherwise to be genuine responses.