Brain activation during cognitive control tasks differs substantially between people but is reliable within individuals.

The neural organization of cognitive control has been extensively studied using neuroimaging methods, but this organization is still not well understood. We argue that two factors may have contributed to this elusiveness. First, most previous research has relied on group-averaged results, which may provide a misleading representation of individual brains. Second, most fMRI studies study the brain only under a limited number of conditions, making it challenging to provide fine-grained distinctions in the functions associated with specific regions. Recent precision neuroimaging approaches have demonstrated substantial promise in furthering understanding of the human brain through repeated sampling of individual participants. However, most precision imaging work still relies on resting-state fMRI or a small number of tasks. In the present study, we demonstrate the utility of a novel dense imaging approach, which combines precision neuroimaging with an unusually large task battery. We demonstrate that patterns of neural activity associated with cognitive control tasks are significantly more similar within-person than between people, even after controlling for anatomical similarity, suggesting that these patterns are person-specific and reliable. In addition, we demonstrate that within-person and between-person similarity changes significantly across tasks, suggesting that some tasks may be more suited for exploring individual differences in cognitive control than others. Together, our findings highlight the potential value of a precision approach and the benefit of using a large number of tasks to further understanding of cognitive control.