INTRODUCTION

1. EFFECTS OF ACUTE ETHANOL CONSUMPTION ON SEXUAL AROUSAL AND SEXUAL RISK TAKING Merritt, N. R. P. 1, Janssen, E., 1,2, Cohen, J., 3 , Finn, P. 1 1Department of Psychology, Indiana University, Bloomington; 2 Kinsey Institute for Research in Sex, Gender, and Reproduction; 3 Department of Counseling and Educational Psychology, Indiana University, Bloomington Interestingly, the number of sexual partners in the computer task did not have a clear effect, with 10 partners leading to the lowest risk intent scores. ABSTRACT This psychophysiological study explored the effects of alcohol on sexual response and sexual risk taking. We failed to replicate previous findings on the effects of alcohol on genital and subjective sexual arousal in men and women. Also, while we did not find support for the ‘alcohol myopia’ theory, we did find preliminary support for the ‘disinhibition hypothesis’ of alcohol’s effect on sexual risk taking, using a novel, policy-capturing computer task. Effect of alcohol on sexual intercourse intent We found a significant main effect of gender (F(1,78)=18.64, p<.01) and an interaction of condition by gender (F(5,390)=3.68, G-G<.05). Follow-up analyses showed that, for men, intent ratings after the second and third film were higher than those after the first film, with the ratings being highest after the third film. For women, the intent ratings were not significantly different. We also found a significant interaction of condition by session (F(4,312)=3.14, G-G<.05). Follow-up analyses indicated that ratings after the third film were significantly higher than those after the first film, but only in the alcohol condition. To test the alcohol myopia hypothesis, we computed beta weights for attractiveness (an impelling cue; based on the subject’s own ratings) and partner number (supposedly an inhibitory cue) at baseline in the computer task. A difference score was calculated to reflect whether the impelling or the inhibiting cues contributed more to their (initial) intent scores. This score, however, did not predict subsequent intent scores. This suggests that the disinhibition hypothesis may account better for the effects of alcohol than the alcohol myopia hypothesis. INTRODUCTION Despite the common perception that alcohol increases sexual risk taking, the available evidence is inconclusive. Some studies even have found that alcohol decreases sexual risk taking. Disinhibition theory (MacDonald et al, 2000) predicts that alcohol will increase sexual risk taking. Steele and Josephs (1990), however, have suggested that ‘alcohol myopia’ may better explain the relationship between alcohol and sexual risk taking. Their alcohol myopia theory proposes that alcohol, because it decreases the number of stimuli one can consider when making decisions, will increase one’s initial propensity to take or avoid risks. This is the first laboratory investigation using an alcohol challenge to test the alcohol myopia theory. In addition, this study attempts to replicate previous findings on the effects of alcohol on sexual response (e.g., Farkas and Rosen, 1976, Briddell and Wilson, 1976; Wilson and Lawson, 1978). RESULTS Effects of alcohol on physiological sexual arousal Using a repeated-measures ANOVA and difference scores from the initial baseline, we found a main effect for film on genital responses in men and women. Women responded more strongly to the second than to to the first erotic film (F(1,40)=7.8, G-G<.01) and men responded less strongly to the third film as compared to the first and second (F(1,38)=15.2, G-G<.01; F(1,38)=10.9, G-G<.01). However, we found no significant main or interaction effects of session (alcohol or juice). Effects of alcohol on subjective sexual arousal Overall, the later films were rated as being more arousing than the earlier films (linear contrast; F(2,144)=6.548, G-G<.05). Again, no effects of session (alcohol or juice) were found. There was a trend for men to, as compared to women, rate the films as being more sexually arousing. METHODS Forty-four female (N=22) and male (N=22) heterosexual participants (mean age = 24) attended two experimental sessions. Both sessions involved viewing 3 erotic videos, separated by neutral videos, and consuming drinks prior to the last two videos. In one session, the drink was cranberry juice. In the other session, the drink was vodka and cranberry juice, to take the participant’s blood alcohol to .025 for the second film and .08 for the third film. Physiological responses were recorded with the Rigiscan in men, and with the vaginal photoplethysmograph (VPA) in women. Before and after the erotic videos, participants completed a computer task and a brief questionnaire. The computer task presented pictures of opposite-sex persons and a description of this person’s number of past sexual partners (0,1,3,10, or 30). Participants indicated for each slide, on a scale of 1 to 9, how likely they were to have sexual intercourse with the depicted person . CONCLUSIONS We failed to replicate several previous findings on basic physiological and subjective sexual arousal responses to alcohol. Using a novel, policy-capturing computer task we did not find support for the alcohol myopia model. However, we did find some support for the disinhibition model. Supported by the Society for the Scientific Study of Sexuality and NIH grants P50 AA07611 and R01 DA14119