Inclusion Criteria:  Age between 18-64. Relapsing remitting multiple sclerosis Been newly prescribed a new disease modifying medication for MS (either Zeposia or other high dose oral efficacy medication) or healthy volunteer who can speak English fluently.  Exclusion Criteria:  History of head injury, stroke, seizures, or any other significant neurological event other than MS Flare up of MS symptoms within the past month. History of significant psychiatric illness (for example, bipolar disorder, schizophrenia, or psychosis) or a current diagnosis of Major Depressive Disorder. Pacemaker or other implanted electrical device, brain stimulator, aneurysm clip (metal clips on the wall of a large artery), metallic prostheses (including metal pins and rods, heart valves, and internal hearing aids [cochlear implants]), permanent eyeliner, implanted delivery pumps, or shrapnel fragments. left handed. Not able to have an MRI