Inclusion Criteria- Clinically defined, unilateral, hemiparetic stroke with radiologic exclusion of other possible diagnosis
- Stroke onset at least 6 months before enrollment
- Present with Mild/Moderate to Severe arm dysfunction (based on Fugl-Meyer scores of 10 to 45)
- Be medically stable to participate in the study and not have contractures or other impairments that would interfere with the interventional training.
Exclusion Criteria- 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
- Visual loss such that the subject would not be able to see the test patterns on the robot computer monitor
- Botulinum toxin to study arm within four months of study enrollment or if received during the study period
- Unable to comply with requirements of the study
- Participants with a history of a seizure will not be precluded from the study, but will not be enrolled in the TMS portions
- Participants with electromagnetic exclusions (metal implants in the cranium, implanted electronic devices etc.) will not be precluded from the study but will be excluded from the MRI and TMS portions