Explaining the high working memory capacity of gifted children: Contributions of processing skills and executive control.

Intellectually gifted children tend to demonstrate especially high working memory capacity, an ability that holds a critical role in intellectual functioning. What could explain the differences in working memory performance between intellectually gifted and nongifted children? We investigated this issue by measuring working memory capacity with complex spans in a sample of 55 gifted and 55 nongifted children. Based on prior studies, we expected the higher working memory capacity of intellectually gifted children to be driven by more effective executive control, as measured using the Attention Network Test. The findings confirmed that intellectually gifted children had higher working memory capacity than typical children, as well as more effective executive attention. Surprisingly, however, working memory differences between groups were not mediated by differences in executive attention. Instead, it appears that gifted children resolve problems faster in the processing phase of the working memory task, which leaves them more time to refresh to-be-remembered items. This faster problem solving speed mediated their advantage in working memory capacity. Importantly, this effect was specific to speed on complex problems: low-level processing speed, as measured with the Attention Network Test, did not contribute to the higher working memory capacity of gifted children.