To achieve these goals, we will recruit 40 individuals over the age of 65 to participate in the study. Each participant will undergo baseline cognitive assessment. Based on the assessment results, he / she will be allocated to the HA block or the MCI block. Within each block, participants will be randomized to a treatment group or a placebo control group. The treatment group will undergo 10 sessions of the mSMT, while the placebo control group will undergo 10 sessions of memory exercises. We have used this placebo condition in multiple randomized clinical trials in the past, with success. Repeat assessments will then occur within one week of completing treatment, 6 months after completing treatment, one year after completing treatment and 2 years after completing treatment. Each assessment will evaluate new learning and memory abilities as well as multiple other aspects of cognitive functioning through a neuropsychological assessment (NP). Participants will also complete an assessment of global functioning (AGF) which evaluates cognitive functioning in daily life. In addition, we will collect neuroimaging data on a subsample of participants willing and able to complete imaging procedures