Early Markers of Cognitive Change and Alzheimer s Disease

Background: \- The Baltimore Longitudinal Study of Aging (BLSA) is a long-term study of human aging. To see how the brain changes with age, researchers will study BLSA participants who are at least 60 years old. In particular, researchers are looking for early markers of possible Alzheimer's disease and other conditions that cause memory loss. To do so, they will give tests of memory and brain function, and stay in close contact with participants. Objectives: \- To study cognitive changes that occur in normal aging and in people who develop memory problems. Eligibility: \- Individuals at least 60 years of age who are participating in the BLSA. Design: * There are three parts to this study. These study procedures will be done under the usual BLSA guidelines. * Participants will take paper and pencil tests. The tests measure skills such as language, attention, memory, and problem solving. They will also ask questions about emotions and feelings. * Participants will give the name and phone number of a person who knows them well and sees them often. Researchers will ask this person to fill out questionnaires on the effects of aging on the participant. These questions will monitor the participant's memory and ability to function independently. * Participants will have regular phone calls between study visits. These calls will help to keep their information up to date. * Participants will continue on this study for as long as they are able to participate.