The Somatic Marker Hypothesis and Sexual Decision Making: Understanding the Role of Iowa Gambling Task Performance and Daily Sexual Arousal on the Sexual Behavior of Gay and Bisexual Men.

Background: The sexual decision-making literature suggests that sexual arousal and behavior are associated. The somatic marker hypothesis suggests that individual neuropsychological differences in decision making, as measured by the Iowa Gambling Task (IGT), may moderate these associations; however, this hypothesis has yet to be tested with event-level sexual behavior data.

Purpose: We hypothesized that (a) daily sexual arousal would be positively associated with likelihood of engaging in sex and condomless anal sex (CAS) and (b) IGT scores would moderate these associations such that the associations would be stronger among those with higher IGT scores.

Methods: We used daily diary data from 334 highly sexually active gay and bisexual men to examine the main and interaction effects of sexual arousal and IGT scores on sexual engagement and CAS.

Results: As hypothesized, daily sexual arousal was positively associated with greater odds of both sexual engagement and CAS with casual male partners. Individual-level IGT performance significantly moderated the day-level association between arousal and sexual engagement, which was stronger for men with higher IGT scores. There was no main effect of IGT scores on either sexual behavior outcome, nor did it moderate the association between arousal and CAS.

Conclusions: These findings highlight the influence of sexual arousal on sexual engagement, which differed by IGT scores; the effect of arousal on CAS was much less variable and may not be moderated by neurocognitive factors. This study supports the importance of exploring integrated behavioral/biomedical interventions to improve individual decision making to prevent HIV infection.