Half of the participants will be randomized to tDCS group, while the other half will be randomized to receive sham tDCS. Active vs. sham treatment will be randomly using computer generated lists. Subjects and researcher-administrators of tDCS and testers or evaluators will be blind to treatment.The main cognitive outcome measure, the MCCB, will be administered at baseline and 1 day after the last tDCS session.Participants will be scanned once prior to tDCS sessions, and within one day after the 10th tDCS sessions using our Siemens 3T Verio MRI scanner.