Cognition (measured at baseline, after the 12 week intervention and after 6 month follow-up). Memory and executive function will be measured as follows: 1) Memory function as indexed by the California Verbal Learning Test-II: learning slope for trials 1-5 and long delay retention57, and 2) Executive function as indexed by: the Delis-Kaplan Executive Function System Trails Test, and Color-Word Interference Test58. Also, participants will be fully characterized on cognitive function by the ADRC, including the National Alzheimer's Coordinating Center Uniform Dataset.