Duchenne Muscular Dystrophy is a genetic disease that causes progressive muscle weakness. There is now substantial evidence that boys with this disease do not demonstrate age-related gains in their cognitive skills. The goals of this study are (i) to use a technology-enabled neurobehavioral assessment called National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) to assess brain development over time; (ii) engage with key-stakeholders to understand how neurodevelopmental problems like attention-deficit hyperactivity, autism spectrum affects individuals (and/or) families, so that we can understand meaningful effects of a potential treatment at an individual level, and (iii) to investigate using brain magnetic resonance imaging (MRI) changes in brain connectivity.