. >> after suffering a stroke five years ago, 62-year-old darryl holmes lost the ability to do things that he used to take for granted. >> i couldn't turn pages in a book, i didn't have that kind of manual control. i couldn't tie my tie or shoelaces. >> but last year, the retired army veteran and urban planner, was selected to take part in a study in washington d.c., in chicago. researchers used an external brain stimulation technique, using waves to a part of the brain that's often impaired by strokes, where fine motor skills are controlled. >> when i navigate to the right spot, it's a concentration of jurons. and when we saw his fingers move, we were over an area that had a high concentration of connections down to our fingers. it's the area of the brain that would light up if i were to play the piano, so using the stimulator drives the motion. >> after a stroke, the healthy parts of the brain become increasingly active as they try to compensate for the injury. it quiets and calms those overactive areas, giving the damaged parts of the brain a chance to recover. >> only 50% of peopl

. >> reporter: after suffering a stroke five years ago darryl holmes lost the ability to do what he took for granted. >> i couldn't do tasks like turning becames in a book -- pages in a booklet i didn't have that control. i couldn't tie a tie. >> the urban planner was elected to take part in a pioneering study at the rehabilitation institute of chicago. researchers used a brain wave technique. voluntary movement and fine movement are controlled, and they navigate to the right spot and a concentration of newerons are projected to the muscles and hands. we were over an area with a high concentration of connections to the finger. the area of the brain that would light up if i play the piano or use the area myself. >> after a stroke it is active as they tried to compensate for the injury. aiming for the waves quiet and calms those areas, giving the damned areas of the brain a chaps to recover. >> 50% of people after a stroke get hand function back. most do not have good hand function. >> used in combination with stroke therapies, 80% of the participants regained use of hands and arms. >> 800