PROJECT SUMMARY Social wellbeing and cognitive health are two pillars of successful aging, and they are interrelated. Three decades of research have consistently shown that social isolation is associated with declines in cognitive functioning. Although existing literature has explored the individual-level risk and protective factors, researchers' attention has been less paid to the extent to which physical and social characteristics of the living environment affect social isolation and cognitive health. The Ecological Theory of Aging (ETA) posits environmental factors have significant influences on health and social wellbeing. Negative physical characteristics of the environment were hypothesized to be related to increased social isolation and cognitive decline longitudinally. An increasing amount of research investigated the association between ICT use and social isolation, yet whether ICT use would interact with the effect of environmental factors on the risk of social isolation has not yet been empirically tested. Besides, the influence of ICT use on cognitive health has not been well understood. Promoting social interaction using technology-based approaches have the potential to alleviate social isolation among older people and prevent cognitive decline. The proposed dissertation work (F99) will examine the effect of physical and social environments of living on social isolation and cognitive health. The effects of ICT use will be investigated within living contexts. Multi-level modeling and structural equation modeling methods will be employed to conduct secondary data analysis using data from the National Health & Aging Trend Study (NHATS) wave 5 to 9. The postdoctoral stage (K00) is guided by the overarching aim of building knowledge on the behavioral and contextual pathways that could explain the association between social isolation and cognitive decline and developing a community-based behavioral health intervention. At the K00 phase, the PI will increase understanding of the social isolation and cognitive health research landscape by conducting a systematic review. Longitudinal data from the ongoing Internet-based Conversational Engagement Clinical Trial (I-CONECT) will be analyzed to examine the association between social isolation and change in neuropsychological outcomes. The PI will utilize the longitudinal data collected with the Collaborative Aging Research Using Technology (CART) platform to investigate the relationships between daily activities, social engagement, and the cognitive health of older participants. Knowledge to be built at F99 and K00 stages will be synthesized to inform the participatory co-design of a technology-facilitated intervention program for social isolation and cognitive decline. The proposed research will produce knowledge on the influence of environmental factors on social isolation and cognitive health, and achieve the PI’s long-term professional goal of developing behavioral health intervention to address social isolation and prevent the onset of Alzheimer's Disease and Related Dementias.

PROJECT NARRATIVE The proposed dissertation work will contribute to the fundamental knowledge with longitudinal empirical evidence on the influence of physical, social environmental factors on social isolation and cognitive health, and contextualized the role of technology use. The postdoctoral research will build knowledge on the behavioral and contextual pathways that could explain the association between social isolation and cognitive decline in later life. Knowledge to be built in the predoctoral and postdoctoral stages will be synthesized to inform the development of a technology-facilitated community-based intervention program to reduce social isolation and prevent cognitive decline among older adults.