1	Phallometry in Research and Clinical Diagnosis Ray Blanchard, PhD Head, Clinical Sexology Services Law & Mental Health Program Centre for Addiction and Mental Health Department of Psychiatry University of Toronto
2	Lunchtime Lecture Presented to the Department of Psychology, Northwestern University, Evanston, Illinois, USA May 2007
3	DEFINITION AND PURPOSE OF PHALLOMETRY Psychophysiological procedure for assessing erotic interests in males Test stimuli—potentially erotic objects or activities Measured response—penile tumescence Interpretation of results—degree of penile tumescence reflects subject’s relative attraction to tested stimuli Organ of primary interest
4	ORGAN OF PRIMARY INTEREST
5	PHALLOMETRY VS. BRAIN IMAGING Cheaper Immediate interpretation Clean signal Diagnostic accuracy established
6	OVERVIEW OF PRESENTATION Physical measurement of penile tumescence Stimulus modalities and materials Clinical applications Research applications
7	MEASUREMENT OF PENILE TUMESCENCE Circumference (mercury-in-rubber strain gauge) Volume (true plethysmography) Comparison of methods
8	STRAIN GAUGE
9	STRAIN GAUGE PLACEMENT
10	APPARATUS FOR VOLUME MEASUREMENT (PLETHYSMOGRAPHY) Used in CAMH lab Not commercially available About 10,000 patients assessed at CAMH since 1968
11	CYLINDER SCHEMATIC
12	CUFF
13	INFLATED CUFF
14	CYLINDER OVER CUFF
15	COMPARISON OF VOLUMETRIC AND CIRCUMFERENTIAL METHODS
16	SIMULTANEOUS RECORDING OF PENILE VOLUME AND CIRCUMFERENCE
17	INTRA-SUBJECT CORRELATIONS BETWEEN VOLUMETRIC AND CIRCUMFERENTIAL RESULTS AS A FUNCTION OF MAXIMUM CIRCUMFERENCE INCREASE
18	CONCLUSIONS Penile circumference may actually decrease when penis first starts filling with blood Circumferential and volumetric methods show excellent agreement above 10% of full erection Volumetric method is superior at lower levels of arousal
19	STIMULUS MODALITIES AND MATERIALS Not standardized across laboratories Depends on parameter assessed, i.e., preferred object (males vs. females, adults vs. children) or preferred activity (consensual sex, sadism, masochism, etc.) Still photographs Pre-recorded audio narratives Videotapes or DVDs Combination of modalities
20	SAMPLE STIMULUS MATERIALS Audiotaped narrative “You are watching a late movie on TV with your neighbours’ 12-year-old daughter. You have your arm around her shoulders, and your fingers brush against her chest. You realize that her breasts have begun to develop.…”
21	THREE-SCREEN SET-UP
22	CLINICAL APPLICATIONS PHALLOMETRIC ASSESSMENT OF AN INDIVIDUAL PATIENT
23	PRESENTATION Young adult male outpatient No criminal charges Somewhat inconsistent historian Presenting complaint, erotic attraction to boys around 11 years of age Reported no attraction to females of any age
24	OUTPUT 1
25	OUTPUT 2
26	OUTPUT 3
27	OUTPUT 4
28	PATIENT’S IPSATIZED AND AVERAGED RESPONSES TO SEVEN STIMULUS CATEGORIES
29	CONCLUSION Although patient reported no attraction to females of any age, he did respond substantially to prepubescent girls No detectable response to adult men or adult women
30	SENSITIVITY AND SPECIFICITY OF THE PHALLOMETRIC TEST FOR PEDOPHILIA IN NON-ADMITTING SEX OFFENDERS Accuracy of assessment Sensitivity—percentage of pedophilic men who are correctly diagnosed as pedophilic Specificity—percentage of nonpedophilic men who are correctly diagnosed as nonpedophilic Clinical challenge of nonadmitters Blanchard et al. (2001). Psychological Assessment, 13, 118-126.
31	SUBJECTS 82 offenders against adult women 172 offenders against unrelated children 70 offenders against children/stepchildren All professed greatest sexual attraction to females age 17 or older
32	SUBDIVISION OF SUBJECTS BY SEXUAL HISTORY Offenders against children subdivided by number of victims (1, 2, ≥3) Offenders against women subdivided by number of victims + consenting adult partners (1-5, 6-23, ≥24) Reason for subdivision—need for ”gold standard”
33	RESULTS
34	RESULTS
35	CONCLUSIONS Sensitivity of phallometric testing for pedophilia is about 60% when specificity is about 95% Similar results were obtained by other researchers
36	RESEARCH APPLICATIONS WHAT DISPOSES MEN WHO PREFER ADULT WOMEN TO APPROACH LITTLE GIRLS?
37	PREVALENCE OF PEDOPHILIA IN SINGLE-VICTIM OFFENDERS Perhaps 50% Motivation of non-pedophiles? Examined with unpublished data analyzed specifically for this luncheon talk
38	SELECTION OF “PURE” GYNEPHILES Consenting patients with complete data = 2,229 Maximum self-reported attraction to females age 17 or older No or lesser self-reported attraction to females 15–16 No self-reported attraction to females under 14 No self-reported attraction to males of any age
39	SELECTION OF “PURE” GYNEPHILES (CONT.) No sexual offenses against females under 17 No sexual offenses against males of any age No child pornography use No consenting adult male partners Greatest phallometric response to adult females Pure gynephiles = 214
40	PENILE REPONSE TO MALE AND FEMALE ADULTS AND CHILDREN
41	RESULTS AND CONCLUSIONS T-tests for pairs showed that responses to prepubescent girls were significantly greater than responses to neutral stimuli, but responses to males did not differ from responses to neutral stimuli This ad hoc study confirms Freund et al. (1972). The female child as a surrogate object. Archives of Sexual Behavior, 2, 119–133 Men whose primary sexual interest is in adult women tend to produce slight but detectable penile responses to moving or still photographs of nude prepubescent girls
42	RESEARCH EXAMPLE #2: PHALLOMETRIC CLASSIFICATION AS INDEPENDENT VARIABLE Blanchard et al. (2007). IQ, handedness, and pedophilia in adult male patients stratified by referral source. Sexual Abuse, 19, 285–309 Pedophiles: Phallometric response to prepubescents (of either sex) greater than their responses to pubescents or adults (N = 106) Hebephiles: Phallometric response to pubescents greater than their responses to prepubescents or adults (N = 340) Teleiophiles: Phallometric response to adults greater than their responses to pubescents or prepubescents (N = 386)
43	ESTIMATED FULL SCALE IQ AS A FUNCTION OF PHALLOMETRIC DIAGNOSIS
44	PERCENTAGE OF NON-RIGHT-HANDED MEN AS A FUNCTION OF PHALLOMETRIC DIAGNOSIS