The emergence of collaborative brain function: FMRI studies of the development of response inhibition.

Adolescence marks the beginning of adult-level cognitive control of behavior supported by the brain maturation processes of synaptic pruning and myelination. Cognitive development studies on adolescence indicate that this period is characterized by improvements in the performance of existing abilities including speed and capacity of information processing and the ability to have consistent cognitive control of behavior. Although adolescents can behave at adult levels in some ways, brain imaging studies indicate that the functional organization of brain systems that support higher-cognitive processes are not fully mature. Synaptic pruning allows for more efficient local computations, enhancing the ability of discrete brain regions to support high-level cognitive control of behavior including working memory. Myelination increases the speed of neuronal transmission supporting the collaboration of a widely distributed circuitry, integrating regions that support top-down cognitive control of behavior. Functional brain imaging methods allow for the characterization of the relationship between cognitive development and brain maturation as we can map progressions in the establishment of distributed brain circuitry and its relation to enhanced cognitive control of behavior. We present a review on the maturation (as distinct from "development" in emphasizing the transition to maturity and stabilization) of response inhibition, brain structure, and brain function through adolescence. We also propose a model for brain-behavior maturation that allows for the qualitative changes in cognitive processes that occur during adolescence.