Figure 1.

A simple depiction of the developmental heterochronic model, with regard to changes in short-range relative to long-range structural and functional brain connectivity. In this specific model, autism involves a slower rate of pruning for short-range connections, and schizophrenia involves a faster rate. Neurodevelopmental variation salient to this process may also involve cortical volume and early short-range connectivity that are greater in autism than in typically developing individuals, and reduced in schizophrenia, which will increase the magnitude of the observed variation in developmental trajectories. Frame thickness is shown as proportional to relative degree of short- range connectivity, and arrow size corresponds to rates of differentiation.