Precise functional connections from the dorsal anterior cingulate cortex to the intuitive physics network in the human brain

Abstract

Recent work has identified a set of brain regions that are recruited when people predict how the physical behavior of the world will unfold (here termed the intuitive physics network; IPN). Mounting evidence supports the characterization of this network as a physics simulation engine in the brain, but many fundamental questions about the architecture of the IPN remain unanswered. One such question is what regions provide the key inputs to the network, supplying the necessary information for physical prediction and regulating when and how the IPN is engaged in service of our goals. Here, we investigated the dorsal anterior cingulate cortex (dACC) as a candidate for regulating IPN function. The dACC has long been implicated in "attention for action", driving the focus of processing toward specific object features that are crucial for planning behaviors. The dACC is also richly interconnected with the general regions of frontoparietal cortex where the IPN is situated, but no study has yet investigated whether these connections specifically target the IPN. To address this question, we collected resting state fMRI recordings in seventeen individuals and independently localized the IPN in each person. We computed the resting state correlations of the dACC with voxels across the rest of the brain and found that the strongest functional connections of the dACC not only aligned well with the IPN at the group level, but also precisely mirrored individual differences in the positioning of IPN regions across participants. This tight correspondence points to the dACC being an important input to the IPN. Taken together with previous findings, our results suggest that the dACC might be a key structure for regulating the engagement of the mental physics engine based on motivation, and may provide an interface between the IPN and the brain systems for other cognitive domains such as social reasoning.