The goal of this Pathway to Independence Award is to expand the base of knowledge, methodological expertise, and theoretical development skills of the candidate as he transitions from a post-doctoral trainee to an independent scientist focused on the decision neuroscience of aging. A wealth of behavioral research on the psychology of aging reveals change over the life span in both cognition and motivation. Many prominent theories of cognitive aging are centered on changes in neuromodulation, focusing specifically on the neurotransmitter dopamine (DA). However, DA is not only implicated in variability in cognitive function, but also plays an important role in motivation. Yet, the relation between age-related changes in DA functioning and motivational factors has received little study. The goal of the initial K99 mentored phase is to begin to examine interactions between motivation and cognition across adulthood, increase the candidate's base of knowledge of the dopamine system, gain experience with computational modeling, and expand the candidate's expertise with multiple imaging measures. To achieve these goals, the candidate will conduct a collaborative multimodal imaging project focused on clarifying the link between DA functioning and self regulation (R21-DA033611). The project will include behavioral and fMRI measures of inhibitory control as well as PET measures of receptor availability across the brain in a group of healthy adults. All participants will complete two behavioral tasks that capture distinct aspects of motivated cognitive control and engage distinct, albeit overlapping neural networks. The candidate will begin to extend this line of work as well as his previous work on age differences in decision making into a cross-sectional study of age differences in motivated cognition and decision making in this K99 phase. The proposed R00 project will examine relationships between motivated cognitive control and decision making across adulthood (ages 20-80). In addition to a PET scan, subjects will complete behavioral tasks while undergoing fMRI that assess reward processing and inhibitory control. Participants will also complete a full battery of cognitive and motivational individual difference measures, incentive-compatible behavioral economics tasks, as well as a subset of the Health and Retirement Study (HRS) survey. This project will also serve as a foundational study for the development of a longitudinal multi-modal imaging protocol. Together, the mentored and independent phases of this project will provide a framework toward developing a more integrative and comprehensive theory of human aging that incorporates neuroscientific theories of the role of DA function for cognition and motivation with psychological theories of aging. A long-term goal of the candidate's career is to develop a computationally-informed and neurobiologically-specific theory of motivated cognition across adult development and aging. Support through this mechanism will greatly increase the likelihood of the candidate's obtaining an R01 to support a longitudinal multimodal imaging study at an earlier career stage than otherwise possible.
Relevance The proposal aims to characterize changes in motivation and cognition over the adult life span using behavioral and multimodal neuroimaging techniques. This work will form the basis of a translational research program on age-related change in reward processing and cognitive control, and has the potential to eventually facilitate identification of specific markers for suboptimal decision making in older adults and inform the design of appropriate interventions. The long-term goal of this line of research is to improve the financial and emotional health of older adults by improving decision making at the individual level.
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|Dang, Linh C; Samanez-Larkin, Gregory R; Castrellon, Jaime J et al. (2016) Associations between dopamine D2 receptor availability and BMI depend on age. Neuroimage 138:176-83|
|Josef, Anika K; Richter, David; Samanez-Larkin, Gregory R et al. (2016) Stability and change in risk-taking propensity across the adult life span. J Pers Soc Psychol 111:430-50|
|Samanez-Larkin, Gregory R; Knutson, Brian (2015) Decision making in the ageing brain: changes in affective and motivational circuits. Nat Rev Neurosci 16:278-89|