 The purpose of this study is to design a predictive model of stroke recovery based on baseline measurements of arm movement and brain physiology. The expectation is the development of a formula to predict a persons response to an arm rehabilitation program provided in the chronic phase 6 months or greater post stroke of recovery. The study will include magnetic resonance imaging MRI, transcranial magnetic stimulation TMS, genetic testing using saliva, and an arm exercise program consisting of robot-assisted exercise combined with functional arm exercise called transition to task training TTT. 