Relationship between trust in neighbors and regional brain volumes in a population-based study

Trust is a fundamental part of human interpersonal relationships, and among other complex factors it is shown to be linked with demographic characteristics and specific regions of the brain. The authors utilized a large, community-based database gathered from the Dallas Heart Study to determine specific brain regions associated with an individual's trust in neighbors. A trust questionnaire was taken and regional brain volumes were determined from structural magnetic resonance imaging. Two analyses using logistic regressions in a training set and validation set were performed to investigate the association between measures of trust and bilateral brain region volumes and thickness. A total of 1527 participants were included in the final analysis. Right caudal anterior cingulate cortex thickness and left caudate volume were inversely correlated with neighbor trust, while left amygdala volume was positively correlated with neighbor trust. Greater age and higher level of education were positively correlated with neighbor trust. African Americans showed less neighbor trust than Caucasians and Hispanics. Anterior cingulate cortex, caudate, and amygdala are all integral parts of the salience network; thus, results of this study suggest that the salience network, the brain network responsible for functions such as communication and social behavior, may play a role in the formation of interpersonal trust.