Brain imaging tells how smart you are

What factors distinguish the brains of exceptionally smart humans from those of their average counterparts? Brain size does matter somewhat, accounting for about 6.7 percent of individual variation in intelligence. However, more recent research using brain imaging has identified 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 five percent of variation in individual intelligence. Now, new research from Washington University, St. Louis, suggests that another 10 percent of individual differences in intelligence can be explained by the strength of neural (brain cell) pathways connecting the left lateral prefrontal cortex to the rest of the brain, the Journal of Neuroscience reported.

Brain imaging tells how smart you are (Image credit: Getty Images)

"Our research shows that connectivity with a particular part of the prefrontal cortex can predict how intelligent someone is," suggested Michael W. Cole, postdoctoral research fellow in cognitive neuroscience at Washington University, who led the study. 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 mechanisms that make human behaviour uniquely flexible and intelligent, according to a university statement.

"This study suggests that part of what it means to be intelligent is having a lateral 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," said study co-author Todd Braver, professor of psychology and of neuroscience and radiology in the Washington University School of Medicine. Braver is co-director of the Cognitive Control and Psychopathology Lab at Washington University, in which the research was conducted.