The brain at birth is largely unmyelinated and the process proceeds across the first two decades. But there are no clear transitions in the process. It proceeds at a protracted pace and so correlations are not evident, as revealed by studies that have attempted to identify correspondence between myelinization and some functional change in behavior. In light of this, many have given up on tying myelination to functional advance in any clear way. Maturation of Cortical Areas.
Development proceeds from occipital through temporal and parietal regions.
Last in frontal lobes, where reasonable degree of maturation is achieved in 2 nd year. Functional correspondence with maturation in frontal lobes is suggestive. AAB error disappears, self recognition appears, as do moral emotions. All seem appropriately linked to frontal lobe activity. Role of Experience in Brain Development Role of experience is well documented in the visual and sensorimotor systems.