Developmental plasticity in children: the role of biological risk, development, time, and reserve.

Older views of the functional developmental plasticity of the developing central nervous system (CNS) focused on the protective effect of a young age at the time of insult. In these views, a younger rather than an older age at onset was thought to produce fewer and/or less severe symptoms and a more rapid recovery. More recently, neurobehavioral outcome has been studied in a variety of medical conditions that affect the developing CNS; at the same time, new investigative techniques, such as brain imaging, have elucidated the biological basis of structural and functional brain plasticity. In consequence of a better understanding of the structural and functional consequences of developmental CNS insults, a body of research has emerged that is shaping a new view of functional developmental plasticity, in which neurobehavioral outcome is set by the biological risk associated with a medical condition and moderated by age and development, the time since onset of the condition, and the reserve available within the child, family, school, and community.