Researchers studied a population of young adult women at risk of sexually transmitted infections (STIs) and HIV. They hypothesized that women with higher positive affective bias to sexual stimuli would report higher sexual risk behaviors.1
The opposite proved to be true. The higher-risk group showed significantly less activation in the mesolimbic brain regions and lower affective bias scores to sexual cues, compared with the low-risk group.1
Investigators showed women sexual cues selected from the International Affective Picture System as well as additional sexual cues chosen to reflect the diversity of the study group. The sexual cues included pictures of naked men and romantic situations, says Paul Regier, PhD, post-doctoral researcher in the department of psychiatry at the University of Pennsylvania Perelman School of Medicine.
“The pictures were shown for about half a second — brief, but not so brief that you don’t see what it is,” Regier explains. “Our hypothesis was that those engaging in riskier types of behaviors, more sexual risk behavior, would have higher reward response to those cues. We call it a mesolimbic brain response.”
The idea was that sexual cues would be a goal mechanism, eliciting pleasure, says Anne Teitelman, PhD, FNP-BC, FAANP, family nurse practitioner and associate professor in the department of family and community health at the University of Pennsylvania.
High Risk Showed Low Response
The researchers found women with higher-risk behaviors did not respond favorably to the sexual cues. “To make sense of it, a lot of literature was done in males,” Regier says. “In males, they showed a higher brain response to these cues in those who were engaging in higher-risk behaviors.”
But women showed the opposite effect. The women who reported their partners wore condoms 100% of the time had a higher brain response to the sexual cues when compared with the women whose partners did not wear condoms within the past three months, he explains.
“It’s possible that women feel more weight of the responsibility because they face the consequences of pregnancy that men don’t face,” Teitelman explains. “If they get STIs, they suffer more consequences, like pelvic inflammatory disease, and they face more stigma than do men.”
Women who feel protected by men wearing condoms might feel safer and more able to enjoy sex without worrying, Teitelman adds.
“One could say that women find men sexier if they were to use a condom,” she says. “We can’t prove that in this study, but that’s a potential implication because the women who were more excited by these pictures were the women whose partners used condoms more.”
Intimate Partner Violence Likely
The group most engaged in risky sexual behavior also was most likely to experience intimate partner violence, Regier says. They also are more likely to have a history of STIs. “But we don’t know that for sure,” Teitelman says.
The message for reproductive health clinicians is that women who engage in the riskiest sexual behavior of not using condoms might benefit from pre-exposure prophylaxis (PrEP) to prevent HIV infection, Teitelman notes.
“We can do more now to prevent HIV, using a woman-controlled method that is not just condoms,” she explains. “For those women who are unable to use condoms, PrEP might be a good alternative.”
- Regier PS, Teitelman AM, Jagannathan K, et al. Women at greater sexual risk for STIs/HIV have a lower mesolimbic and affective bias response to sexual stimuli. Front Behav Neurosci 2020;13:1-11.