All participants will undergo a set of baseline cognitive exams/tests, which will take approximately two hours. Participants will be randomly placed in either the experimental group or the control group. The experimental group will undergo approximately 40 hours of training on the Brain Fitness Program over an eight week period. The control group will be contacted once a week for eight weeks about their cognitively stimulating activities (i.e. reading, working on the computer, and puzzles). At approximately the thirteenth week participants from both groups will undergo post-baseline cognitive exams/tests. This evaluation will take approximately two hours. In addition there is an optional neuroimaging study which participants may elect to participate in. Participants who agree to take part in the neuroimaging portion of the study will undergo a baseline MRI scan. At approximately 13 weeks later participants will undergo a post-baseline MRI scan. Both scans will take approximately one hour.