A unique brain area linked to higher cognitive capacities
In a paper published in the science journal Neuron, Oxford University researchers have identified an area of the human brain that appears to be linked to our higher cognitive capacities, such as planning, decision-making, experiential learning, understanding and generating speech. It is unlike anything in the brains of other primates.
Senior researcher Professor Matthew Rushworth of Oxford University’s Department of Experimental Psychology said that “We tend to think that being able to plan into the future, be flexible in our approach and learn from others are things that are particularly impressive about humans. We’ve identified an area of the brain that appears to be uniquely human and is likely to have something to do with these cognitive powers.”
The Oxford team recruited 25 healthy people between the ages of 20 and 45, including 14 women and 11 men, for the study and scanned each person twice. MRI imaging was used to identify key components in the area of the human brain called the ventrolateral frontal cortex. An area of the brain involved in many of the highest aspects of cognition and language, and is only present in humans and other primates. Some parts are implicated in psychiatric conditions like ADHD, drug addiction or compulsive behavior disorders. The study also investigated how these components were connected up with other brain areas. The results were then compared with equivalent MRI data gathered from 25 macaque monkeys.
Language is affected when other parts are damaged after stroke or neurodegenerative disease. A better understanding of the neural connections and networks involved should help the understanding of changes in the brain that go along with these conditions. Professor Rushworth explained that “the brain is a mosaic of interlinked areas. We wanted to look at this very important region of the frontal part of the brain and see how many tiles there are and where they are placed”.
From the MRI data, scientists identified 12 distinct areas of the ventrolateral frontal cortex that worked in different ways across all the individuals. Professor Rushworth says that “Each of these 12 areas has its own pattern of connections with the rest of the brain, a sort of neural fingerprint, telling us it is doing something unique”.
For the next stage of the study, researchers compared the 12 areas in the human brain region with the organization of the monkey prefrontal cortex and discovered something unique to the human brains. The brain scans were strikingly similar at first, with 11 of the 12 areas of the ventrolateral frontal cortex having little or no difference. One tile of the human cortex, however, had no similarity to that of the monkeys: an area called the lateral frontal pole prefrontal cortex.
First author Franz-Xaver Neubert of Oxford University said that “’we have established an area in human frontal cortex which does not seem to have an equivalent in the monkey at all. This area has been identified with strategic planning and decision making as well as “multi-tasking”.