Inclusion Criteria:  Patients with CBS Age range 18-89 Right-handed  Exclusion Criteria:  A history of migraines Have a scalp or skin condition (e.g., psoriasis or eczema) Have any metallic implants, including intracranial electrodes, surgical clips, shrapnel or a pacemaker Have had a head injury resulting in a loss of consciousness that has required further investigation Have diagnosed psychological or neurological disorders Have had a seizure Have had adverse effects to previous tDCS or other brain stimulation techniques (e.g., TMS) Pregnancy Inability or unwillingness to follow directions for study procedures