The cerebellum has been dubbed "a neuronal learning machine", but its importance in development and developmental disorders has only lately been recognised. The cerebellum is assumed to facilitate implicit/procedural learning via the construction and error-driven adjustment of internal models of behaviour during development, which is a period of fast skill acquisition. The cerebellum develops in a similar way to the cerebral cortex, with parts supporting more basic sensorimotor skills (such as the cerebellar anterior lobe [lobules I�V]) maturing earlier than those supporting higher-level cognitive activities (e.g. posterolateral lobule VII). The structural foundation via which the cerebellum can affect activity patterns in distant regions is the closed-loop circuits between the cerebellum and the cerebral cortex. Based on these relationships, it's been hypothesised that cerebellar malfunction or disruption early in development could have a significant impact on the structure and function of the cortical regions into which it projects.