Distinct neural bases of proactive and reactive metacontrol during task switching

Metacontrol enables the retrieval of prior associations between situational contexts and control demands, allowing for rapid implementation of context-appropriate behavior. While its two behavioral modes-proactive and reactive-are well characterized, their underlying neural mechanisms remain insufficiently understood. To address this gap, we conducted a functional magnetic resonance imaging (fMRI) study to examine whether proactive and reactive metacontrol rely on shared or distinct neural substrates. Using a task-switching paradigm, we independently induced proactive metacontrol at the list level and reactive metacontrol at the item level within the same participants, allowing direct comparison between the two metacontrol modes. Proactive metacontrol engaged a distributed network including the superior frontal gyrus, angular gyrus, and frontal operculum-regions associated with sustained working memory and task-rule maintenance. In contrast, reactive metacontrol primarily recruited the inferior frontal gyrus (IFG), consistent with its role in stimulus-driven conflict detection and resolution. Conjunction analysis revealed no overlapping regions between the two metacontrol modes. These findings further support the view that proactive and reactive metacontrol engage functionally and neurally distinct systems.