The left inferior frontal gyrus (LIFG) has been ascribed key roles in numerous cognitive domains, such as language and executive function. However, its functional organisation is unclear. Possibilities include a singular domain-general function, or multiple functions that can be mapped onto distinct subregions. Furthermore, spatial transition in function may be either abrupt or graded. The present study explored the topographical organisation of the LIFG using a bimodal data-driven approach. We extracted functional connectivity (FC) gradients from 1) resting-state fMRI time-series, and 2) co-activation patterns derived meta-analytically from heterogenous sets of task data. We then sought to characterize the FC differences underpinning these gradients with seed-based resting-state FC, meta-analytic co-activation modelling and functional decoding analyses. Both analytic approaches converged on graded FC changes along two main organisational axes. An anterior-posterior gradient shifted from being preferentially associated with high-level control networks (anterior LIFG) to being more tightly coupled with perceptually-driven networks (posterior). A second dorsal-ventral axis was characterized by higher connectivity with domain-general control networks on one hand (dorsal LIFG), and with the semantic network, on the other (ventral). These results provide novel insights into an overarching graded functional organisation of the LIFG that explains its role in multiple cognitive domains.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)