The candidate is a postdoctoral fellow at Mayo Clinic Jacksonville with diverse training and research experience in neuropsychology. The candidate's career goal is to become an independent investigator in the area of cognitive aging, mild cognitive impairment (MCI) and dementia, with a particular focus on minority populations. The proposed multidisciplinary training program will provide the candidate with a mentored research experience in MCI and dementia within the framework of the Mayo Alzheimer's Disease Research Center, and structured didactic training in epidemiology and longitudinal research methods. The proposed study endeavors to address a critical gap in our current understanding of the transition between normal aging and early dementia. African Americans demonstrate elevated rates of numerous biomedical and psychosocial risk factors for dementia, and thus constitute a particularly vulnerable demographic group for disease onset. Indeed, epidemiological evidence suggests that the incidence, prevalence, and lifetime risk of Alzheimer's disease (AD) among African American elders may be twice that of Caucasians. Therefore, the characterization of MCI within this demographic group is of paramount importance. Recent consensus has highlighted the heterogeneous nature of MCI, and it is now clear that at least three clinical subtypes may represent distinct diagnostic and etiological entities (i.e., amnestic MCI;multiple domain MCI with or without memory impairment;single domain MCI). The proposed study is a population-based, cross-sectional investigation of the relationship between health, genetic, and psychosocial factors, and MCI heterogeneity in African Americans aged 65 and older. Specifically, the proposed study aims to: 1) estimate the proportion of MCI clinical subtypes in African Americans aged 65 and older, and 2) investigate the independent and multivariate relationship between health, genetic, and psychosocial factors and MCI subtypes in this demographic group. The geographic target area for this study will consist of 15 contiguous census tracts in Duval County (Jacksonville, Florida), in which at least 80% of individuals of age 65 and older are African American. Ultimately, the proposed research program will address a major public health disparity concern, namely, the increased incidence of AD in the African American population and its prevention via the early and reliable identification of individuals with MCI.