Scientists have discovered what separates humans from our closest living relatives in an area of the brain linked to higher cognitive powers.
Researchers at Oxford University have pinpointed a unique area that is involved in advanced planning and decision-making, features we consider human traits.
The team used MRI images of 25 adult volunteers to identify key areas in the ventrolateral frontal cortex of the brain. They looked to establish how these components were connected with other parts of the brain and compared the results to data taken from 25 macaque monkeys.
Matthew Rushworth, senior researcher on the study, said: "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 ventrolateral frontal cortex area of the brain is involved in the highest aspects of language and cognition. It is only present in humans and other primates and this area is involved in conditions such as ADHD and compulsive behavioural disorders.
Researchers used the MRI data to separate the ventrolateral frontal cortex into 12 areas. Each area had its own pattern of connections, which the authors describe as a "neural fingerprint" that tells them it is doing something unique.
After comparing the data to the monkey MRI images, they found that 11 of the 12 areas were very similar but that one had no equivalent in the macaque, an area known as the lateral frontal pole prefrontal cortex.
First author of the study, Franz-Xaver Neubert, said: "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 multitasking."
"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," Rushworth said.
"We also looked at the connections of each tile – how they are wired up to the rest of the brain – as it is these connections that determine the information that can reach that component part and the influence that part can have on other brain regions."