Brain imaging can predict how intelligent you are, study finds

August 1, 2012 By Gerry Everding, Washington University School of Medicine in St. Louis
New research suggests as much as 10 percent of individual variances in human intelligence can be predicted based on the strength of neural connections between the left prefrontal cortex and other regions of the brain. WUSTL IMAGE / MICHAEL COLE

(Medical Xpress) -- 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 matters somewhat, accounting for about 6.7 percent of individual variation in intelligence. More recent research has pinpointed the ’s prefrontal , 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. Braver is a co-director of the and Psychopathology Lab at Washington University, in which the research was conducted.

One possible explanation of the findings, the research team suggests, is that the prefrontal region is a “flexible hub” that uses its extensive brain-wide connectivity to monitor and influence other brain regions in a goal-directed manner.

“There is evidence that the left prefrontal cortex is the brain region that ‘remembers’ (maintains) the goals and instructions that help you keep doing what is needed when you’re working on a task,” Cole says. “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.”

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.

“We’re suggesting that the left prefrontal cortex functions like a feedback control system that is used often in engineering, that it helps implement cognitive control (which supports fluid intelligence), and that it doesn’t do this alone,” Cole says.

The findings are based on an analysis of functional magnetic resonance brain images captured as study participants rested passively and also when they were engaged in a series of mentally challenging tasks associated with fluid intelligence, such as indicating whether a currently displayed image was the same as one displayed three images ago.

Previous findings relating left prefrontal cortex activity to challenging task performance were supported. Connectivity was then assessed while participants rested, and their performance on additional tests of fluid intelligence and cognitive control collected outside the brain scanner was associated with the estimated connectivity.

Results indicate that levels of global brain connectivity with a part of left lateral prefrontal cortex serve as a strong predictor of both fluid intelligence and cognitive control abilities.

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 .

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.

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4.2 / 5 (5) Aug 01, 2012
So now al we need to do is figure out which gene (or epigenetic factor) puts the development of the left prefrontal cortex into overdrive and: voila.

OK...probably not quite that easy. But I'm willing to bet someone is going to try it on their children.
not rated yet Aug 01, 2012
Of course we already know it is not which gene or which epigenetic factor that's involved. It is so clearly the epigenetic effects of nutrient chemicals and pheromones on intracellular signaling and stochastic gene expression (genetically predisposed, of course), that attempts to examine the molecular biology by looking at brain connectivity and correlate it with intelligence make it impossible to see our well-constructed socio-cognitive niche from the perspective of adaptive evolution, which is clearly first dependent on ecological, social, and neurogenic niche construction. So, please, don't try to tweak the ecological, social, and neurogenic niche construction of your children, just to see if you can increase their intelligence. That's not an intelligent thing to do, is it? Neither is writing rambling sentences that are likely to be read by the unintelligent, but therein lies yet another problem.
5 / 5 (2) Aug 01, 2012
I'm suspicious of studies that take into account remembering pictures to determine intelligence.
4 / 5 (4) Aug 01, 2012
I'm with Antonima. This appears to have been a measure of memory, not of intelligence, and the activity reported seems very similar to that reported for savants:

Neurocase. 2007 Oct;13(5):311-9.
Savant memory for digits in a case of synaesthesia and Asperger syndrome is related to hyperactivity in the lateral prefrontal cortex.
Bor D, Billington J, Baron-Cohen S.

Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK.

SINGLE CASE: DT is a savant with exceptional abilities in numerical memory and mathematical calculations. DT also has an elaborate form of synaesthesia for visually presented digits. Further more, DT also has Asperger syndrome (AS). We carried out two preliminary investigations to establish whether these conditions may contribute to his savant abilities. NEUROIMAGING: In an fMRI digit span study, DT showed hyperactivity in lateral prefrontal cortex when encoding digits, compared with controls....
5 / 5 (4) Aug 01, 2012
"So now al we need to do is figure out which gene (or epigenetic factor) puts the development of the left prefrontal cortex into overdrive and: voila." - Antialias

No More Republicans....
not rated yet Aug 05, 2012
"So now al we need to do is figure out which gene (or epigenetic factor) puts the development of the left prefrontal cortex into overdrive and: voila." - Antialias

No More Republicans....

Yeah? And who would you bag then? Your superior cerebrum would have lost all sense of purpose.

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