Distinct connectivity patterns in clusters of inferior parietal cortex: from a cognitive control hub to modulating cortical areas

Abstract

The inferior parietal cortex (IPC) is a complex brain region, composed of the rostral, the middle and the caudal clusters, and functionally connected to several other parts of the brain. Various executive functions are suggested to be governed by the IPC, however, by ignoring the tripartite structure of this region, contradictory research reports abound in the literature. Here, we elaborated on the functional connectivity patterns of the clusters of the IPC, highlighting evidence that only the rostral cluster of this part of the brain is involved in cognitive control, not the entire IPC. We also underscored the unique connectivity profile of the middle and the caudal clusters which are not accommodated by the traditional classification of brain areas as either being task-based or being related to the resting-state functionality of the brain. The middle and the caudal IPC demonstrate negative functional associations with cortical areas involved in general cognitive functions, executive functions, in addition to the precuneus cortex, proportional to cognitive demand, in a modulating manner, while remaining distinct from resting-state related parts of the cortex.