Brain Connections for Arm Movement After Stroke

Inclusion Criteria: Inclusion Criteria (control participants): * Be 45-90 years of age * Have adequate language and neurocognitive function to participate in training and testing * Be medically stable to participate in the study * Be English speaking Inclusion Criteria (participants with stroke): * Be 45-90 years of age * Clinically defined, unilateral, hemiparetic stroke with radiologic exclusion of other possible diagnosis * Stroke onset at least 6 months before enrollment * Subcortical stroke (ex: internal capsule, deep white matter of posterior frontal lobe) * Present with mild to moderate arm dysfunction * Be medically stable to participate in the study * Be English speaking Exclusion Criteria: (for both groups) * Unable to give informed consent * Have a serious complicating medical illness that would preclude participation * Contractures or orthopedic problems limiting range of joint motion in the potential study arm or other impairments that would interfere with the study activities * Visual loss such that the subject would not be able to see the test patterns on the robot computer monitor * Unable to comply with requirements of the study * Enrollment in another greater-than-minimal risk study * Presence of medical condition or implant that prevents safe administration of TMS or MRI * Pregnancy