I am an epidemiologist with a substantive research interest in cognitive aging, dementia, delirium, and aging and mental health. I trained in Psychiatric Epidemiology at the Johns Hopkins University School of Hygiene and Public Health, Department of Mental Hygiene. I am currently a Professor in the Department of Psychiatry and Human Behavior (DPHB) and in the Department of Neurology at Brown University. I conduct research in the epidemiology of cognitive aging, cognitive or brain reserve, and social and environmental influences on cognitive function. I also serve as director of the Quantitative Science Program at Brown, DPHB. My main methodologic research is directed at the application of psychometric and latent variable models such as item response theory and structural equation models in the area of cognitive reserve, cognitive aging, dementia, and delirium. I serve as biostatistics editor for Alzheimer's & Dementia, the Journal of Applied Gerontology, assistant editor for biostatistics at the Journal of the American Geriatrics Society, and senior associate editor for A&D: Diagnosis, Assessment and Disease Monitoring.