Practice effects in the developing brain: a pilot study.

Functions that rely on dorsolateral prefrontal and parietal cortex, including working memory manipulation, are among the latest functions to mature. Yet, several behavioral studies have shown that children may improve on these functions after extensive practice. In this pilot study, we examined whether children would be able to demonstrate increased frontoparietal brain activation after practice. Twelve-year-old children and young adults practiced for 6 weeks with a working memory manipulation task. Before and after practice, functional magnetic resonance imaging data were acquired. Both children and adults demonstrated better performance, lasting at least up to 6 months after the practice period. Before practice, children showed immature frontoparietal activation for manipulation of information in working memory relative to pure maintenance, specifically during the delay period of the task. After practice, the activation differences between children and adults were considerably reduced, suggesting that children may show increased frontoparietal activation if given extensive practice. These preliminary findings argue against the hypothesis that certain brain structures cannot be engaged because of immaturity. Yet, future studies with larger samples should further examine flexibility in the developing brain, and establish what can and cannot be expected of children across school-aged development.