ABSTRACT
Diffuse excitatory processes—such as those related to the sympathetic nervous system and subcortical structures—are functionally active from birth, partly because of their relevance to organismic survival. But many of the more finely tuned inhibitory systems—which include parasympathetic nervous system activity and higher—order cortical processes, especially in the frontal lobes—are slower to develop and myelinate, and their influence emerges more slowly in the postnatal period.
