This study will look at the effects of a painless, non-invasive form of brain stimulation, called transcranial direct current stimulation, or tDCS. tDCS is thought to increase the brain's ability to change. Participants will be assigned to one of four groups by chance. Three groups will receive tDCS at a level expected to increase the brain's ability to change, and will vary by the areas of the brain that are stimulated. The fourth group will receive tDCS at a level not thought to affect the brain's ability to change. All participants will receive intensive therapy of their impaired arm and hand, focusing on exercises that will improve their ability to function in daily life.
Individuals who experienced a stroke over one year ago will be randomly assigned to receive 1 of 4 different conditions of brain stimulation. All individuals will receive therapy of the hand and arm following the stimulation. This study will try to determine which brain stimulation condition leads to the greatest improvement in hand and arm function.