SUMMARY/ABSTRACT: Project 1 MindCrowd: Precision Aging Cognitive Assessment Through a Web-based Network The overarching goal of the Precision Aging Network (PAN) is to close the gap between cognitive healthspan and human lifespan. We propose that this goal will be best achieved through the use of precision medicine-based approaches to help address individualized susceptibilities to age-related cognitive decline (ARCI) as well as to Alzheimer’s disease (AD) and AD-related dementias (ADRDs). A critical waypoint on the path to this precision approach is the study of a large, diverse cohort of normally aging adults to help us better characterize the multitude of factors – demographic, health, medical, lifestyle, and molecular – that may be predictive of altered risk for ARCI, AD, and ADRD. To achieve this, the PAN has established four Projects that will recruit and study such a cohort, thereby initiating these next steps toward an eventual “Precision Aging” approach. Project 1 plays a critical role in this venture via the continued recruitment and expansion of a large, diverse internet-based cohort. Additionally, Project 1 will empower the selective recruitment of specific participants for in-depth face-to-face characterization by Project 2 as well as contribute to the novel biomarker discoveries in Project 3, and the predictive model development approaches in Project 4. Project 1 will expand our existing internet-based MindCrowd study as follows; (a) increase the enrollment of understudied demographics including Hispanic/Latino and non-Hispanic Black participants, (b) enlarge the web-based test battery to cover additional domains of cognitive functions, and (c) conduct on-going two-year longitudinal assessments using the expanded test battery. The study site (located at www.mindcrowd.org), in operation since January 2013, has already recruited over 213,000 individuals from across the country. The cognitive tasks are available through the study site in both Spanish and English, and all future tasks – developed in collaboration with the Cognitive Assessment and Neuroimaging (CAN) Core E – will be developed as bi-lingual versions as well. We have successfully demonstrated an ability to collect additional self-report survey data as well as blood biospecimens and molecular genetic data from these individuals, even though few participants from this web-based cohort have been seen in-person. Together this demonstrates the importance and feasibility of using the internet to achieve the goal of studying large and diverse samples to power the development of a precision medicine clinical approach. Acquiring the proposed large, diverse cross-sectional and longitudinal data sets will enable us to answer the central research questions proposed by the PAN. Additionally, the data obtained by the PAN will be openly available via regular releases during the granting period in order to be fully available to the national research community studying cognitive aging, AD,...