Functional magnetic resonance imaging (fMRI), with its excellent spatial resolution and ability to visualize networks of neuroanatomical structures involved in complex information processing, has become the dominant technique for the study of brain function and its development. The accessibility of in-vivo pediatric brain-imaging techniques…

It has been 20 years since Bever's (1982) and Strauss and Stavy's (1982) books on U-shaped functions in human development were published. The three target articles in this issue describe several old and new U-shaped functions and new theoretical explanations for their existence. In this article, the authors will comment on two aspects of U-shaped…

The traditional view of development is stage-like progress toward increasing complexity of form. However, the literature cites many examples in which children do worse before they do better. A major challenge for developmental theory, therefore, is to explain both global progress and apparent regression. In this article, we situate U-shaped…