Clinical Research Directory

Inclusion Criteria: * Age between 18-64 * Diagnosed with Relapsing-Remitting Multiple Sclerosis or a healthy volunteer * If diagnosed with MS: has been newly prescribed Tysabri, but has not yet started taking the medication * Can read and 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