The goal of this Phase I trial is to determine the rehabilitative effects gained through the use of a novel computer generated virtual scenario (VS), alone and with a protocol of constraint-induced therapy (CIT), for stroke rehabilitation. Efficacious results of a therapeutic protocol of VS and/or VS enhanced CIT (VS-CIT) could positively impact the lives of stroke survivors through enhanced recovery. The technology we seek to verify through this Phase I STTR proposal could be applied to products directed toward the rehabilitation of stroke victims and perhaps lessen the over 51 billion dollar estimated annual burden from stroke-related disability. Future goals involve determining whether the technology could be developed into products to be used by individuals with disabilities of different causes and types. This STTR proposal has 3 specific aims (SA): 1) Determine if there is a therapeutic effect of VS and/or VS-CIT. 2) Establish the feasibility of a Phase II randomized clinical trial (RCT) to evaluate the efficacy of VS alone and a combined VS-CIT protocol. 3) Fine tune the experimental design and intervention procedures for VS and VS-CIT in a Phase II RCT. These will be achieved as follows: SA 1) We will assess change in performance of a) reaching and grasping actions, b) upper extremity impairment, c) function, and d) disability, resulting from VS and VS-CIT sessions (three weeks ea.) in persons who have sustained a stroke and using an a) index of reach-grasp dexterity with behavioral kinematics recently developed in the Winstein lab, b) a standardized clinical test of impairment (Fugl-Meyer), c) function (Functional Test of the Hemiparetic Upper Extremity), and d) disability (Stroke Impact Scale), respectively. SA 2) Develop practical requirements of the VS technology for a Phase II clinical trial. SA 3) Assess patient satisfaction with the program of VS and VS-CIT and evaluate self-efficacy of arm use with a validated questionnaire. Phase II will establish a broader application in the clinical environment, incorporate patient perspectives, and longer-term outcomes.