Levels of global brain connectivity in a specific part of the prefrontal cortex, as seen with functional MRI (fMRI) brain images, can predict both fluid intelligence and cognitive control ability, according to a study published in the Journal of Neuroscience.
Previous research has shown that brain size and activity in the lateral prefrontal cortex has an effect on individual variation in intelligence. The current study, conducted by Michael W. Cole, PhD, of Washington University in St. Louis, and colleagues, suggests that 10 percent of individual differences in intelligence can be explained by the strength of neural pathways connecting the left lateral prefrontal cortex (LPFC) to the rest of the brain.
“In contrast to studies emphasizing whole-brain network contributions to intelligence or studies emphasizing the contributions of specific regions (or networks) to intelligence, we found that a specific region’s global connectivity predicts intelligence,” wrote Cole et al. “This suggests a reconceptualization of LPFC as a functional hub that uses its brainwide influence to facilitate cognitive control and intelligence.”
More than 100 study participants were recruited from the Washington University undergraduate population, with 94 used for the analyses after exclusion criteria were applied. The researchers first identified regions involved in cognitive control using the N-back working memory task. Resting state fMRI data were then used to test whether these regions had high global brain connectivity relative to the rest of the brain.
Cole and colleagues tested whether the global brain connectivity in various regions reliably predicted intelligence, and found that this was the case only in the left LPFC. “This suggests that there may be a specific brain region that uses brainwide connectivity as a central mechanism for supporting cognitive control and intelligence.”
The LPFC has been previously shown to be the brain region that maintains goals and instructions when working on a task, explained Cole in a release. “So it makes sense that having this region communicating effectively with other regions (the ‘perceivers’ and ‘doers’ of the brain) would help you to accomplish tasks intelligently.”
The findings could have implications for understanding human intelligence, as well as how breakdowns in global brain connectivity contribute to schizophrenia and other mental illnesses.
“Further investigation into the functional relevance of cognitive control hubs, including the possibility that LPFC benefits from high global connectivity due to its unique flexibility, will be essential for understanding the neural architecture underlying human intelligence,” wrote the authors.