Autism spectrum disorders (ASDs) are a heterogeneous group of neurodevelopmental conditions that vary in both etiology and phenotypic expression. Expressions of ASD characterized by a more severe phenotype, including autism with intellectual disability (ASD + ID), autism with a history of developmental regression (ASD + R), and minimally verbal…

Jack and Pelphrey provide a systematic review of neuroimaging studies in understudied populations within the autistic spectrum, focussing specifically on those with minimal verbal ability, intellectual disability and developmental regression. Despite accounting for nearly a third of the autistic spectrum, the number of studies focussing on these…