This is a sub-project of a larger NIDRR Grant. One promising form of robotic training that leverages the power of neuro-plasticity is error augmentation. In this paradigm the computer singles out and magnifies a stroke survivor's movement errors from a desired trajectory, thus forcing the subjects to strengthen their control. Using the VRROOM, a state-of-the-art system which uses haptics (robotic forces) and graphics (visual display) interfaces, a subject's desired trajectory can be determined and the movement errors can be amplified in real-time with dramatic results. This project evaluates a practical approach of error augmentation, using therapist-driven trajectories. The investigators intend to determine clinical efficacy of several types of therapist-assisted error augmentation on retraining the nervous system in functional activities. The investigators will test two experimental treatments in a crossover design. The investigators hypothesize that combined haptic and visual error augmentation will lead to the best functional recovery.