Dr. Smith is focused on understanding how exercise and physical activity affect human brain function and mental health. Dr. Smith's investigations use magnetic resonance imaging (MRI) and neuropsychological testing to examine brain function in people at risk for Alzheimer's disease. Dr. Smith, his team of investigators, and collaborators are interested in the potential efficacy for exercise to affect brain function, physical function, and memory in healthy older adults at genetic risk for Alzheimer's disease, as well as in patients diagnosed with Mild Cognitive Impairment (MCI). The ultimate goal is to provide evidence for exercise to delay conversion to Alzheimer's disease and protect against age-related cognitive decline. In addition, Dr. Smith examines how acute and chronic exercise or physical activity may alter emotional reactivity, attention allocation, and cognitive function among healthy adults and patients with anxiety and/or depressive mood disorders.