Could a brain scan tell you how smart you are?
Brain scans which establish how well different regions of your brain are detected may be able to predict how intelligent you are, a new study claims.
Research suggests that 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.
The findings, published in the Journal of Neuroscience, establish ‘global brain connectivity’ as a new approach for understanding how human intelligence relates to physiology.
Well connected: Ten per cent of intelligence could be explained by the strength of neural pathways connecting the left lateral prefrontal cortex
‘Our research shows that connectivity with a particular part of the prefrontal cortex can predict how intelligent someone is,’ said Michael Cole, PhD, a postdoctoral research fellow in cognitive neuroscience at Washington University and lead author of the study.
He says the research 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.
‘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,’ added study co-author Todd Braver, PhD, professor of psychology in Arts & Sciences and of neuroscience and radiology in the School of Medicine.
One possible explanation of the findings, the research team suggests, is that the lateral prefrontal region is a ‘flexible hub’ that uses its connectivity to monitor and influence other brain regions.
‘There is evidence that the lateral prefrontal cortex is the brain region that “remembers” the goals and instructions that help you keep doing what is needed when you’re working on a task,’ said Prof Cole.
‘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 lateral prefrontal cortex that helps coordinate these processes and maintain focus on the task at hand. This happens 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 lateral 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,’ said Prof Cole.
Brain scans: The findings are based on an analysis of functional magnetic resonance (fMRI) brain images
The findings are based on an analysis of functional magnetic resonance (fMRI) 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 lateral 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 the 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 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, Prof Cole suggests.