Cortical properties of adults with autism spectrum disorder and an IQ>100

Previous studies on cortical volume and thickness measures in autism spectrum disorders (ASD) show inconsistent results. We acquired structural magnetic resonance images of 30 individuals with ASD and individually matched controls and extracted surface-based and deformation-based morphometry measures. All participants had an IQ>100. Neither surface-based cortical thickness nor deformation based gyrification measures differed significantly across groups. Significant decreases but no increases of the gyrification index and sulcus depth could only be observed in the ASD group before correcting for multiple comparisons. This finding suggests that possible cortical anomalies in ASD are either weak or, given the heterogeneity of findings in earlier studies, might only apply to small ASD-subgroups.