Age-Related Differences in Ventral Striatal and Default Mode Network Function During Reciprocated Trust

Description: Our social relationships change as we grow older. Despite the ubiquity of these changes, little is known about how they impact neural and behavioral responses to financial decisions involving other people. We examined this problem in the context of a trust game played with three partners varying in social closeness (friend, stranger, computer) while participants underwent fMRI. We found that, relative to younger adults, older adults demonstrated both blunted striatal activation and enhanced DMN-TPJ connectivity during experiences of reciprocated trust from friends relative to strangers and computers. These results suggest that older adults demonstrate altered neural representations of social closeness within financial exchanges involving trust, which may expose them to increased risk for financial exploitation perpetrated by strangers. ADDITIONAL INFO AND NAMING CONVENTIONS: In this study, we tested two imaging-related pre-registered hypotheses, which are explained in our manuscript: H2.1: We expected enhanced reward-related responses within the striatum when experiencing reciprocity from a close friend relative to other partners; however, we expected this effect would be stronger in younger adults. H2.2: We expected age-related differences in striatal responses to reciprocity with different partners to be tied to increased connectivity between with the default-mode network (DMN). Images that are related to these hypotheses include "H2.1" or "H2.2" in the name, and images linked to specific figures in the paper include the figure number. Aside from one image that did not have suprathesholded results (id: 512030), all images include both a thresholded (with thresh at the end of the name) and unthresholded image. ABBREVIATIONS: Friend (F), Stranger (S), Computer (C), Reciprocate (Rec), Defect (Def), psychophysiological interaction analyses (PPI), network PPI (nPPI).