Adjacent Dorsolateral Prefrontal Cortex (DLPFC) Regions Participate in Distinct Large-Scale Networks Differentially...

Human prefrontal cortex (PFC) is heterogenous. In monkeys, side-by-side PFC regions, including within dorsolateral PFC (DLPFC), show distinct long-range anatomical projection profiles, raising the possibility that adjacent regions might specialize as a consequence of the distributed networks in which they are embedded. Consistent with this possibility, recent findings in humans provide evidence for PFC regions domain-specialized for scene (spatial) processing and language processing that are adjacent to distinct domain-flexible regions responding to traditional cognitive control demands. Here we tested functional specialization of PFC regions linked to another domain-specialized network recruited by certain forms of social processing (theory-of-mind, ToM, tasks). Using within-individual precision neuroimaging approaches, side-by-side DLPFC regions embedded within parallel distributed networks were identified within the idiosyncratic anatomy of each individual (N=13). Functional responses between these distinct regions revealed a robust functional double dissociation: one DLPFC region was preferentially recruited by ToM tasks and an adjacent DLPFC region by working memory task demands. The region responding to social processing demands was small and its position varied slightly from one person to the next suggesting why it may have been underappreciated in past group-based analyses. These findings add to evidence that PFC features more functional specialization than commonly appreciated and further that the specialization of juxtaposed regions within PFC can be understood by examining the distributed networks within which the regions are embedded.