Maturation of widely distributed brain function subserves cognitive development

Cognitive and brain maturational changes continue throughout late childhood and adolescence. During this time, increasing cognitive control over behav ior enhances the voluntary suppression of reflexive/impulsive response tend encies. Recently, with the advent of functional MRI, it has become possible to characterize changes in brain activity during cognitive development. In order to investigate the cognitive and brain maturation subserving the abi lity to voluntarily suppress context-inappropriate behavior, we tested 8-30 year olds in an oculomotor response-suppression task. Behavioral results i ndicated that adult-like ability to inhibit prepotent responses matured gra dually through childhood and adolescence. Functional MRI results indicated that brain activation in frontal, parietal, striatal, and thalamic regions increased progressively from childhood to adulthood. Prefrontal cortex was more active in adolescents than in children or adults; adults demonstrated greater activation in the lateral cerebellum than younger subjects. These r esults suggest that efficient top-down modulation of reflexive acts may not be fully developed until adulthood and provide evidence that maturation of function across widely distributed brain regions lays the groundwork for e nhanced voluntary control of behavior during cognitive development. (C) 200 1 Academic: Press.