Brain Imaging Can Predict How Intelligent You Are, Study Finds

When it comes to intelligence, what factors distinguish the brains of exceptionally smart humans from those of average humans?

As science has long suspected, overall brain size matters somewhat, accounting for about 6.7 percent of individual variation in intelligence. More recent research has pinpointed the brain’s prefrontal cortex, a region just behind the forehead, as a critical hub for high-level mental processing, with activity levels there predicting another 5 percent of variation in individual intelligence.

Now, new research from Washington University in St. Louis suggests that another 10 percent of individual differences in intelligence can be explained by the strength of neural pathways connecting the left prefrontal cortex to the rest of the brain.

Published in the Journal of Neuroscience, the findings establish “global brain connectivity” as a new approach for understanding human intelligence.

“Our research shows that connectivity with a particular part of the prefrontal cortex can predict how intelligent someone is,” suggests lead author Michael W. Cole, PhD, a postdoctoral research fellow in cognitive neuroscience at Washington University. The study is the first to provide compelling evidence that neural connections between the left prefrontal cortex and the rest of the brain make a unique and powerful contribution to the cognitive processing underlying human intelligence, says Cole, whose research focuses on discovering the cognitive and neural mechanisms that make human behavior uniquely flexible and intelligent.

“This study suggests that part of what it means to be intelligent is having a prefrontal cortex that does its job well; and part of what that means is that it can effectively communicate with the rest of the brain,” says study co-author Todd Braver, PhD, professor of psychology in Arts & Sciences and of neuroscience and radiology in the School of Medicine. {snip}

{snip}

While other regions of the brain make their own special contribution to cognitive processing, it is the left prefrontal cortex that helps coordinate these processes and maintain focus on the task at hand, in much the same way that the conductor of a symphony monitors and tweaks the real-time performance of an orchestra.

{snip}

Although much remains to be learned about how these neural connections contribute to fluid intelligence, new models of brain function suggested by this research could have important implications for the future understanding — and perhaps augmentation — of human intelligence.

{snip}