Abstract: My research interests focus on rehabilitation engineering and include motor control/learning of healthy subjects as well as patients. During my talk I will introduce some key aspects of my research topics, especially concerning rehabilitation devices for stroke patients and the neural basis of musician’s dystonia. Sensory disturbance is common following stroke, and sensory loss may inhibit the ability of patients to use their hands in their daily activities. In other words, the “manipulation capability”, even though they have a good motor function, is compromised. Particularly, "motor function" is assessed by passive and active range of motion (spasticity problems included), while "manipulation capability" is the ability of grasping or pinching objects in daily activities. We hypothesized that sensory feedback training might enhance task-oriented training and improve manipulation capability. Therefore, we developed a novel sensory feedback system by electrical stimulation in which patients receive a sensory feedback during pinching or grasping objects. I will show the proposed system and results of a first feasibility test with stroke patients. On the other side, through long-term and excessive motor training, musicians may develop musician’s dystonia (MD). Typically in MD at the hand, the affected fingers become uncontrollable mostly during playing a specific musical instrument, but respond normally to other motor activities. Some studies recently found relations between cerebellum functioning and dystonia disease. For instance, patients with MD show less cerebellar activity during a bilateral finger-tapping task, and greater cerebellar activation is observed during writing in writer’s cramp (another form of task-specific focal dystonia). However, it remains unclear how the cerebellar abnormality results in abnormal muscle contraction in MD. We hypothesized that the cerebellar activity might functionally modulate activity of the motor-related areas, yielding abnormal muscle contraction during movements in MD. We have conducted MRI experiments to validate this hypothesis and I will explain our current findings.