Computerized Tests of Cognitive Decline in Presymptomatic Alzheimer's Disease

The investigators will study performance on computerized cognitive tasks in healthy participants of different ages to gather normative data for newly developed computerized cognitive tests. These tests are designed to permit the early detection of individuals at risk of age-related cognitive decline.

In Group A, the investigators will evaluate the performance of healthy older participants (N = 300, age range 60 to 89 years) for three days at enrollment and then at 6-month intervals for three years thereafter. The goal is to characterize changes in performance to aging and task experience in a group of older subjects. In Group B, the investigators will compare the performance of normal participants (N = 100, age range 18 to 89) on computerized and manually administered cognitive tasks. In Group C, the investigators will gather normative data from participants across the age range (N = 100, ages 18 to 89) for three days at enrollment, to better characterize test-retest reliability scores on Day 1 tasks. In Group D, the investigators will evaluate the performance of healthy older participants (N = 1200, age range 60 to 89 years) for three days at enrollment and then at 6-month intervals for three years thereafter. In the aim of better understanding health disparities in cognitive testing, this group will be divided into four cohorts: 300 African American participants; 300 Asian American participants; 300 Latino English-speaking participants; and 300 Latino Spanish-speaking participants, who will complete a Spanish translation of our computerized cognitive tests.