Methodologically, a multimodality approach will be used. Magnetic stimulation will allow detailed analysis of maps of representation areas in the primary motor cortex and motor thresholds and evaluation of central motor conduction. EEG and movement-related cortical potentials will provide information about coherence and timing of activation of different brain regions. PET scan will identify regions activated in association with performance of motor tasks. Registration of this information onto MRI will allow precise identification of brain regions associated with reacquisition of motor skills on the affected side after stroke.