Inclusion Criteria- experienced unilateral hemispheric ischemic or hemorrhagic stroke at least 3 months but no more than 7 years prior
- exhibit voluntarily shoulder flexion of the affected arm ≥30° with simultaneous elbow extension ≥20°. The investigators reason that persons at this motor ability level have residual arm activation and enough ability to engage in treatment-related reaching movements elicited by the computer games
- baseline FMA-UE score of at least 19 points but no more than 52 points (out of 60 points) based on previously published research by this study's investigators in which categories were defined based on post-stroke UE motor impairment
- passive range of motion in affected shoulder, elbow and wrist within 20 degrees of normal values
- 21-90 years of age
- a caregiver or friend who is willing to assist with the set up and operation of the computer game throughout the 6 week intervention.
Exclusion Criteria- lesion in brainstem or cerebellum because lesions in these locations my interfere with the visual-perceptual and cognitive skills needed for motor re-learning as is expected to occur as a result of the intervention
- presence of other neurological disease that may impair motor skills (e.g., Parkinson's Disease)
- pain in the affected arm that interferes with reaching movements
- significant cognitive impairment, defined as Montreal Cognitive Assessment score < 22
- orthopedic condition or impaired corrected vision that alters the kinematics of reaching
- unable to travel to the UE Motor Function Laboratory in Charleston, South Carolina 4 times (pre-, mid- post- and retention testing).