Neurobiological mechanisms of daily life activity participation in older adults - Project Summary The proposed research will use behavioral, psychophysiological, neuroimaging, and naturalistic approaches to understand the mechanisms underlying daily life activity participation in older adults and its linkages to Alzheimer’s disease pathology. There is a strong foundation of research demonstrating reliable age-related decreases in many aspects of cognitive ability that are coupled with changes in the neuromodulatory systems that support these functions. Yet older adults also seem to experience clear shifts in motivational prioritization, encountering increased costs associated with engagement in cognitively effortful activities. Likewise, older adults report an overall decrease in participation in cognitively effortful activities in daily life. However, engagement in cognitively effortful activities has been associated with the maintenance of cognitive function and decreased risk of developing Alzheimer’s disease in older adulthood, underscoring the critical need to understand the relationship between motivation and changes to neuromodulatory systems in older adulthood, and how these might impact older adults’ daily life engagement in cognitively effortful activities, to be able to promote cognitive health in older adults. The current proposal provides a novel perspective on this issue, by employing a multilevel, multimodal framework to study the behavioral and neurobiological mechanisms underlying age-related shifts in the motivation to perform cognitively effortful activities, and to directly link these changes with daily life activity participation and Alzheimer’s disease pathology. The project directly tests the hypothesis of age-related motivational reprioritization and its relationship to activity participation by using the combination of ecological momentary assessment (EMA) and passive sensing approaches involving repeated sampling of older adult daily life activity participation. Further, these rich naturalistic observations of daily life activities are coupled with PET imaging measures of catecholamine synthesis (i.e., dopamine, norepinephrine) and behavioral and psychophysiological measures of cognitive effort in older adults to test for the relationships between cognitive effort-related motivation, neuromodulation, and daily life activities in older adults. Finally, the project will feature the first-ever assessment of the relationship between in vivo markers of Alzheimer’s disease pathology and daily life activity participation in older adults, using state-of-the-art tau PET and intensively sampled daily life activity participation assessed with both EMA and cutting-edge passive sensing methods. A key component of the project is its exploration of mobile technologies as a means to monitor older adult activity participation during daily life, and their potential utility as a tool to enhance cognitive engagement. As such, the proposed work represents an essential first step in developing both behavioral and biological targets for motivational interventions that promote the maintenance of cognitive health and resilience to pathology in older adulthood.
