Brain regions associated with moment-to-moment adjustments in control and stable task-set maintenance

While there is some consensus that cognitive control involves both a capacity to rapidly adjust to unexpected challenges and a capacity to prospectively maintain task-sets over longer timescales, there is disagreement concerning the neural implementation of these capacities. Some accounts, for example, associate rapid adjustments in control with a network of lateral prefrontal and parietal cortices and task-set maintenance with a network of anterior cingulate and insular cortices. Other accounts propose almost the opposite associations. The present study compared these accounts by means of a hybrid fMRI design. Twenty-three right-handed adults were administered a conflict-adaptation paradigm in which the frequency of compatible trials, and therefore, demands on rapid adjustments and stable task-set maintenance, varied parametrically across conditions. Increased demands on moment-to-moment adjustments were associated with a profile of phasic activity in anterior cingulate cortex, anterior insula, and inferior parietal cortex. By contrast, increased demands on stable task-set maintenance were associated with increased sustained activity in medial superior frontal gyrus. Theoretical implications are discussed.