Functional magnetic resonance imaging (fMRI) studies in subjects with autism spectrum disorder (ASD) indicate that there may be differences in regional brain function in response to several different face recognition and social attribute discrimination tasks. In a few specific brain regions, fMRI has shown differences between normal controls and ASD subjects. However, these previous studies have been limited in terms of their ability to localize information spatially and to delineate subgroups within ASD. This proposed research is centered on developing unique mathematical approaches that consider functional and structural information together in order to develop more sensitive and spatially-specific measurements. These approaches will be tested in their ability to separate subgroups in the autism spectrum (autism, Asperger's, PDD-NOS) using both functional and structural measures.