Human frontopolar cortex plays a causal role in digesting complex information during decision making

Abstract

Abstract The ability to digest complex information is critical to many decisions that are non-trivial. However, the underlying mechanism is however broadly unclear. Here, we focused on investigating the causal role of the lateral frontopolar cortex (FPl), an area greatly evolved in the human brain, in processing complex choice information. This was achieved via three experiments that collectively involved transcranial magnetic stimulation (TMS), task-free functional magnetic resonance imaging (fMRI), task-based fMRI, and computational modelling. First, we found that disrupting FPl using TMS impaired decision making with complex information. Second, we developed a computational model that consistently explains complex choice behaviour across three experiments. The same model also explains mechanistically that the FPl-TMS effect was due to diminished complexity in integrating information. Finally, fMRI data revealed stronger FPl signals were related to more complex integrations. Together, our results suggest a causal role of FPl in digesting complex information during decision making.