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 per cent of individual variation in intelligence. More recent research has pinpointed the brain’s lateral prefrontal cortex, a region just behind the temple, as a critical hub for high-level mental processing, with activity levels there predicting another 5 per cent of variation in individual intelligence.
Now, new research from Washington University in St Louis suggests that another 10 per cent of individual differences in intelligence can be explained by the strength of neural pathways connecting the left lateral 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 in the United States.
The study is the first to provide compelling evidence that neural connections between the lateral 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 behaviour uniquely flexible and intelligent.
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. The findings also may offer new avenues for understanding how breakdowns in global brain connectivity contribute to the profound cognitive control deficits seen in schizophrenia and other mental illnesses, Cole suggests.
Source: Washington University in St Louis