Abstract
The prefrontal cortex (PFC) executively controls many aspects of visual attention and working memory. It modulates the priority in visual pathways to spotlight an attended or to-be-remembered location in space, or other contextual information. In this respect, neuroimaging evidence suggests that the frontal eye field (FEF) and inferior frontal junction (IFJ) primarily code spatial and non-spatial (feature or object) representations, respectively. However, it is still unclear whether such functional segregation is also reflected in the underlying functional connectivity patterns of those structures. Here, we hypothesized that FEF, for the greater part, is functionally connected to spatiotopically organized regions in the dorsal ('where') visual stream, whereas IFJ has predominant functional connectivity with areas in the ventral ('what') visual stream. To this end, we applied a seed-based functional connectivity analysis to resting-state magnetoencephalography (MEG) recordings. We parcellated the brain according to the multimodal Glasser atlas and tested whether the spontaneous activity of each parcel in the ventral and dorsal visual pathway has predominant functional connectivity with FEF or IFJ. The results show that FEF has a robust power correlation with the dorsal visual pathway in beta and gamma bands. In contrast, the anterior part of IFJ (IFJa) has a strong power coupling with the ventral visual stream in delta, beta, and gamma oscillations. Moreover, while FEF is directly phase coupled with the superior parietal lobule in the beta band, IFJa is phase coupled with the middle and inferior temporal gyrus in delta and gamma oscillations (icoh, wpli). We argue that these intrinsic connectivity fingerprints are congruent with each brain region's function. Therefore, we conclude that FEF and IFJ have dissociable connectivity patterns that fit their respective functional roles in spatial vs. non-spatial attention and working memory.