Study reveals how connections in brain are linked to intelligence

Berlin: Intelligent people have better connections in certain brain regions that are more strongly involved in the flow of information, a study has found.

Differences in cognitive abilities - and the resulting differences for example in academic success and professional careers - are attributed to a considerable degree to individual differences in intelligence.

The research, published in the journal Scientific Reports, shows that these differences go hand in hand with differences in the patterns of integration among functional modules of the brain.

Researchers from the Goethe University Frankfurt in Germany combined brain scans from over 300 persons with modern graph theoretical network analysis methods to investigate the neurobiological basis of human intelligence.

They had earlier identified brain regions - among them the prefrontal cortex - in which activation changes are reliably linked to individual differences in intelligence.

Until recently, however, it was not possible to examine how such intelligence regions in the human brain are functionally interconnected.

Earlier this year, the team found that in more intelligent persons two brain regions involved in the cognitive processing of task-relevant information - the anterior insula and the anterior cingulate cortex - are connected more efficiently to the rest of the brain.

Another brain region, the junction area between temporal and parietal cortex that has been related to the shielding of thoughts against irrelevant information, is less strongly connected to the rest of the brain network.

"The different topological embedding of these regions into the brain network could make it easier for smarter persons to differentiate between important and irrelevant information - which would be advantageous for many cognitive challenges," said Ulrike Basten, from Goethe University Frankfurt.

The study shows that in more intelligent persons certain brain regions are clearly more strongly involved in the exchange of information between different sub-networks of the brain in order for important information to be communicated quickly and efficiently.

On the other hand, the team also identified brain regions that are more strongly de-coupled from the rest of the network in more intelligent people. This may result in better protection against distracting and irrelevant inputs.

"We assume that network properties we have found in more intelligent persons help us to focus mentally and to ignore or suppress irrelevant, potentially distracting inputs," said Basten.

"It is possible that due to their biological predispositions, some individuals develop brain networks that favor intelligent behaviors or more challenging cognitive tasks," she said.

"However, it is equally as likely that the frequent use of the brain for cognitively challenging tasks may positively influence the development of brain networks," she added.