Are You Safe or Should I Go? How Perceived Trustworthiness and Probability of a Sexual Transmittable Infection Impact Activation of the Salience Network

Functional imaging studies indicate that both the assessment of a person as untrustworthy and the assumption that a person has a sexually transmitted infection are associated with activation in regions of the salience network. However, studies are missing that combine these aspects and investigate the perceived trustworthiness of individuals previously assessed with high or low probability of a sexually transmitted infection. During fMRI measurements, 25 participants viewed photographs of people preclassified as having high or low HIV probability and judged their trustworthiness. In a postrating, stimuli were rated for trustworthiness, attractiveness, and HIV probability. Persons preclassified as HIV- in contrast to those preclassified as HIV+ were rated more trustworthy and with lower HIV probability. Activation in medial orbitofrontal cortex was higher for those rated and preclassified as HIV- than HIV+. Based on the individual ratings, but not the preclassification, there was significantly higher activation in the insula, amygdala, anterior cingulate cortex, and nucleus accumbens in response to untrustworthy than to trustworthy faces. Activation of the salience network occurred when a person was judged as untrustworthy, but not according to a preclassification. Activation in the medial orbitofrontal cortex, a structure associated with reward, was enhanced when a person was perceived as trustworthy and also when a person was preclassified with low HIV probability. Our findings suggest that trustworthiness and HIV- perception have consistency across samples, while the perception of risk and associated activation of the salience network has restricted cross-sample consistency.