Project Summary (Supplement). This supplement aims to bring Dr. Marilyn Horta, who is from an underrepresented background in the sciences at our institution and in the US, to work under the parent grant R01AG072658. This project offers an ideal context for Dr. Horta's research and career development given her goals of becoming an independent, productive researcher in aging and decision neuroscience. Dr. Horta would have the opportunity to (i) expertise in the identification and optimization of neurocognitive processes of learning to trust and distrust in particularly vulnerable and currently understudied older adult populations (i.e., individuals with chronic pain; disadvantaged groups); (ii) skills in advanced statistical analysis of behavioral and neuroimaging data; and (iii) enhanced presentation and academic writing abilities. Dr. Horta will work closely with her mentoring team that spans across the three parent grant sites and includes balanced expertise in in cognitive and socioemotional experimental aging and neuroimaging analysis (Dr. Ebner), computational modeling of reinforcement and learning (Dr. Wilson), decision neuroscience (Dr. Lighthall), and clinical pain and aging (Dr. Fillingim). On her initiative, Dr. Horta has successfully obtained pilot funding to investigate decision making among older adults with chronic pain, a particularly vulnerable and currently understudied older adult group regarding trust-related decision making. Integrating her clinical expertise in chronic pain populations under the parent grant, Dr. Horta will significantly contribute to all three parent grant aims. In particular, she will advance Aim 1, which is to confirm age deficits in learning to trust in an adult lifespan sample and determine the extent to which social cues of trustworthiness bias trust-related decisions and learning in older adults, by differentiating chronic pain status among the parent grant sample; and with her newly learned skills in computational modeling under the supplement will be able to isolate specific learning biases (e.g., social cue, loss aversion, and recency) under consideration of chronic pain status. Further, Dr. Horta's training in advanced neuroimaging data analysis will directly contribute to Aim 2, which seeks to confirm altered neurocircuitry underlying age-associated learning deficits; again, extending this work to chronic pain. Finally, findings from the analyses under Aims 1 and 2 will directly inform Aim 3 toward identifying the best target for training the malleability of the neurocircuitry underlying trust-learning deficits in vulnerable older adults.