In this study the investigators aim to investigate the effects of two different types of non-invasive brain stimulation techniques -- repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) on motor function in stroke. This is a cross-over study where subjects will receive 5 sessions of stimulation (each separated by 1 week) -- with either active tDCS and sham rTMS, sham tDCS and active rTMS or both sham tDCS and rTMS.

Inclusion criteria:

(1) All subjects must be between the ages of 18-90.

Exclusion criteria:

1. History of Major depression, as defined by Beck Depression scale 30;

2. Any substantial decrease in alertness, language comprehension, or attention that might interfere with understanding instructions for motor testing;

3. Contraindications to TMS

   • history of seizures
   • unexplained loss of consciousness
   • metal in the head
   • frequent or severe headaches or neck pain
   • implanted brain medical devices.

4. Contraindications to tDCS

   • metal in the head
   • implanted brain medical devices

5. Advanced liver, kidney, cardiac, or pulmonary disease;

6. A terminal medical diagnosis consistent with survival < 1 year;

7. Coexistent major neurological or psychiatric disease (to decrease number of confounders);

8. A history of significant alcohol or drug abuse in the prior 6 months;

9. Subjects may not be actively enrolled in a separate intervention study targeting stroke recovery and any other clinical trials;

10. Subjects with global aphasia and deficits of comprehension

11. Pregnancy. Female subjects of child bearing potential will be asked to take a pregnancy test. If the pregnancy test is positive, the subject may not enroll in the study.

12. Use of neuropsychotropic medications [healthy subjects only]

Additional inclusion criteria for stroke subjects:

1. First-time clinical ischemic or hemorrhagic cerebrovascular events - evidenced by a radiological (or physician's) report
2. Weakness, defined as score of less than 55 (out of 66) on arm motor Fugl-Meyer (FM) scale
3. Stroke onset >6 months prior to study enrollment .

Additional exclusion criteria for stroke subjects:

1. Subjects may not have already received TMS and/or tDCS stimulation for stroke;
2. History of epilepsy before stroke or episodes of seizures within the last six months;