This study will be the first investigation of neural mechanisms underlying cognitive deficits in children and adolescents with cystinosis. It will determine specific areas of weakness and sparing across two main sensory modalities and two cognitive processing levels. These domains are among the major determinants of successful learning in everyday and academic settings. Importantly, the roles of neuro-structural and neuro-functional abnormalities in cognitive manifestations of the disorder will be determined. Therefore, our findings may serve as the basis for new medicinal and cognitive intervention strategies that may lead to greater personal and academic success of these children.