ABSTRACT
Behavioral and neuroimaging studies of children with brain lesions have greatly contributed to our understanding of the dynamic process of neurocognitive development. Carefully designed behavioral research on the nature and timing of cognitive skill acquisition in the normally developing brain has corroborated these data, although the relationship between neural substrate and typical cognitive development is relatively poorly understood. The ability to obtain measures of structural and functional brain changes in children noninvasively has triggered a new era. Models of neurocognitive development can now be tested, and disorders of childhood development with cognitive or behavioral components can be more precisely characterized. A wide range of neuropsychological studies have documented developmental
trajectories in healthy children across a variety of tasks that incorporate executive abilities. The different time course of the emergence of skills and attainment of adult ability levels supports a model of executive function comprised of discrete components. Elements of executive function include attentional control, goal-directedness, and mental flexibility. It is well established that the frontal lobes, and in particular the prefrontal cortex, have a significant role in mediating these abilities. Nevertheless, there is little data on how development of different brain regions might contribute to the successful attainment of relevant skills. These data would not only advance our theoretical appreciation of brain-behavioral relationships within the unique developmental context but also provide important information on the breakdown of these relationships in childhood-onset disorders. This chapter outlines the advances made in this area using magnetic resonance imaging (MRI).
