The neurophysiology of sexual desire, with particular reference to paedophilia.

Bancroft has proposed a central arousability system as an androgen-sensitive neurophysiological substrate of sexual desire. The present paper describes the author's explorations of a brain-wave measure, the contingent negative variation (CNV), as a putative index of sexual desire under conditions of sexually-relevant stimulation in paedophilic child sex offenders and in non-offender control men. As a group, the former showed undifferentiated CNV responses to adult and child stimuli, unlike non-paedophilic child sex offenders and controls, who showed larger CNVs to adult than to child stimuli. These results suggest that CNV may be usefully developed as an adjunct to penile plethysmographic (PPG) assessment of deviant sexual interests in offenders. Some possible directions for future research are indicated.