Autism is a lifelong, heterogeneous, and impairing developmental disorder. To fully understand the neurodevelopmental nature of this disorder it is important to broaden the developmental perspective by including old age. The course of autism during later life has remained exempt of empirical scrutiny, but the possibility for such research is emerging now, as the first cohorts formally diagnosed with autism are currently approaching old age. This presents a unique opportunity for a new line of research. People with autism show deficits in cognitive control in childhood and adulthood. These deficits are associated with structural and functional abnormalities in the underlying fronto-striatal network. In healthy people this brain network and the related cognitive control abilities deteriorate when aging. If and how aging has an impact on the behavioral and brain anomalies in individuals with autism is unknown. Based on what is known about autism and normal aging, I hypothesize that age-related compensatory brain mechanisms cannot be recruited in people with autism, which leads to a faster decrease in cognitive control in people with autism as compared to controls. To test this novel hypothesis, I propose a series of studies across adulthood (20-30, 40-50, & 65-75 years) focusing on central aspects of cognitive control and the integrity of its underlying brain circuitries. Analyses will focus on individual differences between groups, but also within groups to capture the substantial heterogeneity characterizing both autism and healthy aging. The integrative approach of using newly developed tasks and various brain imaging techniques enables us to study the relationship between behavioral and symptomatic age-related changes and alterations in brain circuitries in autism. Results from the proposed studies will advance the understanding of (1) neurodevelopmental aspect of this lifelong disorder; (2) relationship of cognitive control to the underlying brain networks in autism; (3) heterogeneity across people with autism.