Laura Chaddock, Kirk I. Erickson, Ruchika Shaurya Prakash, Michelle W. Voss, Matt VanPatter, Matthew B. Pontifex, Charles H. Hillman, Arthur F. Kramer

We used functional magnetic resonance imaging (fMRI) to examine brain activity of higher fit and lower fit children during early and late task blocks of a cognitive control flanker paradigm. For congruent trials, all children showed increased recruitment of frontal and parietal regions during the early block when the task was unfamiliar, followed by a decrease in activity in the later block. No within-group changes in congruent accuracy were reported across task blocks, despite a decline in performance across all participants, likely due to fatigue. During incongruent trials, only higher fit children maintained accuracy across blocks, coupled with increased prefrontal and parietal recruitment in the early task block and reduced activity in the later block. Lower fit children showed a decline in incongruent accuracy across blocks, and no changes in activation. We suggest that higher fit children are better at activating and adapting neural processes involved in cognitive control to meet and maintain task goals.