This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We are proposing a controlled study to investigate rehabilitation treatment-induced changes in brain activation patterns as a measure of cerebral plasticity in long-term stroke survivors. Two types of interventions will be investigated: Aerobic exercise (AEX) and Bilateral arm training with rhythmic auditory cueing (BATRAC). Both interventions involve the repetition of simple functional movements. Repetitive movements including arm or leg exercise training was shown to improve motor function in chronic stroke patients with residual upper or lower extremity Hemiparesis, even if employed 6-24 months after the disabling stroke. The mechanisms, by which these repetitive interventions improve limb function, are unknown. Functional magnetic resonance imaging (fMRI) can visualize changes in cortical representations of muscle groups and has the potential to elucidate some of the general mechanisms of AEX-improved stroke recovery. Besides gaining a better pathophysiologic understanding (Specific Aims 1 & 3), the identification of structures involved in the recovery process may guide patient selection (Specific Aim 2, e.g. if the initial stroke involves one of these critical areas, benefit from AEX or BATRAC may be minimal).