The long-term goal of our research is to improve health and well being in daily life, especially in older age. We aim to identify psychological and neurobiological strengths at all stages of adulthood that can be used to enhance everyday decision making. Our earlier work was heavily focused on financial decision making. We are continuing to study financial choice but we are also expanding our work to examine daily decisions to engage in physical activity or make food choices.
Our research is at the intersection of several subfields within psychology, neuroscience, and economics including human development, affective science, health psychology, cognitive neuroscience, behavioral economics, and experimental finance. We use a combination of behavioral and neuroimaging techniques ranging from detailed measurement of functional brain activity (fMRI) and neuroreceptors (PET) in the laboratory to experience sampling in everyday life. Our behavioral lab and offices are located in the Duke Center for Cognitive Neuroscience and we conduct our neuroimaging research at the Duke Brain Imaging and Analysis Center.
Affect and Motivation
Much of the work in our lab examines how changes in goals across adulthood influence affective and motivational function. In early work we demonstrated that basic reward processing and frontostriatal brain function remains intact well into old age. These findings were replicated multiple times by our group and others. In recent work, we've shown that age differences in motivational goals influence social and health-related decision making. For example, age differences in tolerance of time delays, reward uncertainty, and effort demands vary depending on whether the available rewards are monetary, social, or health-related. Older adults want social and health rewards now and with certainty. We are currently using this information about how goal priorities may shift preferences to enhance interventions aimed at increasing physical and cognitive health and well being in older age (see Translation section below).
Learning and Decision Making
A major goal of our research is to improve models of the psychology and neurobiology of aging. The psychology of aging has revealed that some functions improve with age while others decline. For example, older adults have an experience advantage over younger people but are disadvantaged by increasing limitations in fluid cognition. We examine the implications of these changes for decision making in old age. Much of this work has focused on the role of learning ability for making financial decisions. In this line of studies we use recent, novel learning as an model of fluid cognition and accumulated knowledge (crystalized learning) as a model of experience. This set of studies on learning and decision making aims to make contributions not only to models of cognition and aging but to our understanding of fluid and crystalized intelligence more generally.
The neuromodulator dopamine is implicated not only in variability in cognitive function but also plays an important role in motivation. In a meta-analysis of 30 years of human neuroimaging (PET/SPECT) research, we quantified declines in the dopamine system (receptors, transported, synthesis) across adulthood as 3.7–14.0% per decade. In contrast to steep declines in receptors and transporters, there was no significant effect of age on DA synthesis capacity. This cumulative aggregation of decades of research identified presynaptic mechanisms that may partially account for previously unexplained phenomena whereby older adults appear to use dopaminergic resources effectively. The relation between age-related declines in dopamine function and motivational factors have received little study. In several projects in progress, we are exploring these interactions using multimodal neuroimaging protocols that include comprehensive behavioral individual difference measures as well as fMRI and PET imaging of dopamine receptors. We are interested in how pharmacological interventions can enhance cognition, and how behavioral interventions can enhance neurochemical function. For example, in a recent study we showed that the age-related losses in dopamine receptor availability described above are minimized in moderately physically active middle-aged and older adults.
Translation from the Lab to Everyday Life
We do basic science that has translational potential. We study behaviors in the lab that we believe are directly related to real-world behavior. We have documented that performance on many laboratory tasks is related to real-world financial behavior. Together with collaborators at the Stanford Center on Longevity we are developing methods to facilitate collaboration between traditional academic labs and private sector partners with the goal of accelerating the translation and application of research findings. We, and many others, have documented the neuroprotective effects of physical activity in older age. There are several new studies in the lab focused on using what we've learned about motivation and aging to identify optimal incentives to increase physical activity, especially in middle-aged and older adulthood. These studies involve neuromarketing-like experiments to test the effectiveness of health messages, development of personalized electronic messaging to enhance motivation, and daily monitoring of physical activity in everyday life.