PROJECT SUMMARY Approximately 16 million Americans serve as family caregivers for a person with Alzheimer's disease and related dementias and this care can take a physical and emotional toll. Understudied is how this informal care can affect caregiver cognitive health and associated daily sleep and activities, all of which are modifiable health behaviors. Engaging in personally meaningful, and cognitively stimulating activities can benefit cognitive and sleep health among dementia care dyads. Despite the importance of activity engagement for cognitive functioning and sleep quality, existing assessment of activities and outcomes is often self-reported asynchronously at global levels. Contemporaneous assessment of activities, sleep, and cognitive health and well-being would significantly advance research in this area by 1) conducting objective assessments on daily sleep and activities within a dyadic context, 2) determining how the social context of caregivers' assistance for the individuals with dementia's activity engagement moderates the associations between cognitive health and well-being, and daily sleep and activities, and 3) determining how a chronic stress biomarker, hair cortisol concentration, mediates the activities- and sleep-cognition associations in naturalistic settings. The proposed mentored career development award combines a rigorous program of research, mentorship, and didactics to facilitate the candidate's growth toward an overall career goal of becoming an independent investigator focused on informing the design of interventions for aging caregiving dyads with complex care needs including dementia to improve both partners' well- being. The training aims will assist the candidate in acquiring: 1) grounded knowledge of clinical care and educational needs among care dyads relating to neurocognitive assessment, functioning, and understanding the clinical aspects of dementia, 2) specialized skills in the assessment, analysis, and interpretation of daily sleep and activity measures and the biological measure of chronic stress that link to the dementia care situation and specifically to caregiver cognitive health and well-being, and 3) expertise in the application of intensive repeated measures designs that will generate novel insights on proximal risk and protective factors for poor caregiver outcomes within the dyadic context. The training aims seek to further develop the candidate's expertise as an interdisciplinary researcher in the area of later-life dementia family caregiving and align closely with the research aims to: 1) quantify caregiver daily sleep characteristics with actigraphy and determine their associations with caregiver cognitive functioning and well-being; 2) quantify caregiver daily activity characteristics with accelerometry and determine their associations with caregiver cognitive functioning and well-being; and 3) To characterize how caregiver assistance for PLwD's activity engagement moderates, and how hair cortisol concentration mediates associations of sleep➔cognition and activities➔cognition. An integrated, biopsychosocial approach to identifying protective factors that promote resilience and reduce harmful risk factors will inform the development of future targeted caregiver interventions in the dyadic context for a highly vulnerable aging population.

PROJECT NARRATIVE This project addresses three key limitations in the field of dementia family caregiving research, by focusing on caregiver cognitive health outcomes, quantifying two daily health behaviors of sleep and activities, considering caregivers' assistance to engage individuals with dementia in daily activities and the dyadic context of caregiving, and a chronic stress biomarker when examining the hypothesized associations. The project will generate critical information on how caregiver cognitive health is associated with daily sleep and activities within the dyadic context, elucidating the social context and biological mechanisms that relate to varying caregiver outcomes.