Sixty-two normal controls will be included; controls will be screened in the NINDS Movement Disorders Outpatient Clinic. After screening and consenting, controls will have neurological and physical examinations. Controls with chronic illnesses, taking any medication that affects the CNS will be excluded. Female subjects of child bearing potential will have a pregnancy test and an interview prior to the study to ensure that pregnant subjects will not participate in the study. They will be asked to abstain from alcohol for one week before the study. More controls will be needed in order to ensure that the sequence is working prior to the acquisition of data, since the sequence has only been used in the 1.5T MRI scanner and we will be using the 3T.