Social reward and nonsocial reward processing across the adult lifespan: An interim multi-echo fMRI and diffusion...

Social relationships change across the lifespan as social networks narrow and motivational priorities shift. These changes may affect, or reflect, differences in how older adults make decisions related to processing social and non-social rewards. While we have shown initial evidence that older adults have a blunted response to some features of social reward, further work in larger samples is needed to replicate our results and probe the extent to which age-related differences translate to real world consequences, such as financial exploitation. To address this gap, we are conducting a 5-year study funded by the National Institute on Aging (NIH R01-AG067011). Over the course of the funding period (2021-2026), this study seeks to: 1) characterize neural responses to social rewards across adulthood; 2) relate those responses to risk for financial exploitation and sociodemographic factors tied to risk; and 3) examine changes in risk for financial exploitation over time in healthy and vulnerable groups of older adults. This paper describes the preliminary release of data for the larger study. Adults (N = 114; 40 male / 70 female / 4 other or non-binary; 21-80 years of age M = 42.78, SD = 17.13) were recruited from the community to undergo multi-echo fMRI while completing tasks that measure brain function during social reward and decision making. Tasks probe neural response to social reward (e.g., peer vs. monetary feedback) and social context and closeness (e.g., sharing a monetary reward with a friend compared to a stranger). Neural response to social decision making is probed via economic trust and ultimatum games. Functional data are complimented by a T1 weighted anatomical scan and multi-shell diffusion-weighted imaging (DWI) to enable tractography and assess neurite orientation dispersion and density. Overall, this dataset has extensive potential for re-use, including leveraging multimodal neuroimaging data, within subject measures of fMRI data from different tasks - data features that are rarely seen in an adult lifespan dataset. Finally, the functional data will allow for developmentally sensitive cross-sectional analyses of differences in brain response to nuanced differences in reward contexts and outcomes (e.g., monetary vs. social; sharing winnings with a friend vs. stranger; stranger vs. computer).