Lateral prefrontal cortex contributes to fluid intelligence via multi-network connectivity

Our ability to effectively adapt to novel circumstances – as measured by general fluid intelligence – has recently been tied to the global connectivity of lateral prefrontal cortex (LPFC). Global connectivity is a broad measure that summarizes both within-network and across-network connectivity. We used additional graph theoretical measures to better characterize the nature of LPFC connectivity and its relationship with fluid intelligence. We specifically hypothesized that LPFC is a " connector " hub with across-network connectivity that contributes to fluid intelligence independently of within-network connectivity. We verified that LPFC was in the top 10% of brain regions in terms of across-network connectivity, suggesting it is a strong connector hub. Importantly, we found that LPFC across-network connectivity predicted individuals' fluid intelligence, and that this correlation remained statistically significant when controlling for global connectivity (which includes within-network connectivity). This supports the conclusion that across-network connectivity independently contributes to the relationship between LPFC connectivity and intelligence. These results suggest LPFC contributes to fluid intelligence by being a connector hub with truly global multi-system connectivity throughout the brain.