Alzheimer's disease-related changes occur in the brain more than 15 years before a person experiences the memory and personality changes associated with the disease. By studying the disease in its earliest stages, scientists hope to find treatments that can prevent or delay the onset of dementia and memory loss. Guest: Sterling Johnson, PhD, Clinical Neuropsychologist, Professor of Geriatrics, University of Wisconsin School of Medicine and Public Health, Associate Director of the Wisconsin Alzheimer's Disease Research Center, Principle Investigator of the Wisconsin Registry for Alzheimer's Prevention (WRAP) Study