A parallel functional topography between medial and lateral prefrontal cortex: evidence and implications for cognitive control.

The dorsomedial and dorsolateral prefrontal cortices (dmPFC and dlPFC) together support cognitive control, with dmPFC responsible for monitoring performance and dlPFC responsible for adjusting behavior. The dlPFC contains a topographic organization that reflects complexity of control demands, with more anterior regions guiding increasingly abstract processing. Recent evidence for a similar gradient within dmPFC suggests the possibility of parallel, hierarchical organization. Here, we measured connectivity between functional nodes of dmPFC and dlPFC using resting-state functional magnetic resonance imaging in humans. We found a posterior-to-anterior connectivity gradient; posterior dmPFC maximally connected to posterior dlPFC and anterior dmPFC maximally connected to anterior dlPFC. This parallel topographic pattern replicated across three independent datasets collected on different scanners, within individual participants, and through both point-to-point and voxelwise analyses. We posit a model of cognitive control characterized by hierarchical interactions--whose level depends on current environmental demands--between functional subdivisions of medial and lateral PFC.