Connectivity and functional diversity of different temporo-occipital nodes for action perception

The temporo-occipital cortex (TOC) plays a key role in body and action perception, but current understanding of its functions is still limited. TOC body regions are heterogeneous and their role in action perception is poorly understood. This study adopted data-driven approaches to region selectivity and investigated the connectivity of TOC nodes and the functional network sensitivity for different whole body action videos. In two human 7T fMRI experiments using independent component analysis, four adjacent body selective nodes were detected within the TOC network with distinct connectivity profiles and functional roles. Action type independent connectivity was observed for the posterior-ventral node to the visual cortex, the posterior-dorsal node to the precuneus and the anterior nodes to the frontal cortex. Action specific connectivity modulations were found in middle frontal gyrus for the aggressive condition with increased connectivity to the anterior node and decreased connectivity to the posterior-dorsal node. But for the defensive condition, node-nonspecific enhancement was found for the TOC-cingulate connectivity. By addressing the issue of multiple nodes in the temporo-occipital network we show a functional dissociation of different body selective centres related to the action type and a potential hierarchy within the TOC body network.