Standing out from the (primate) crowd....

A newly-mapped, uniquely human region of the brain (shown in red). Image courtesy of Oxford University

In 2014, Oxford researchers pinpointed a human brain region unlike anything possessed by our nearest primate relatives. The region, located in the ventrolateral frontal cortex, is central to some of the highest-level decision-making and planning processes which distinguish humans from other primates. The ventrolateral frontal cortex, or vlFC, which is present only in humans and other primates, participates in several of the most complex cognitive and language-related operations.  

According to Oxford’s Dr. Matthew Rushworth, our unique cognitive flexibility, capacity to learn from others and ability to plan are particularly advanced, and likely derive from circuits in this region. 

To locate key parts of the vlFC, and to determine how these areas interact with other brain regions, Dr. Rushworth's team performed MRI scans upon 25 adult humans. After, the results were compared to MRI scans of equivalent regions in 25 macaque monkeys. 

The team found 12 functional areas within the human vlFC consistent among all the test subjects. Of these, 11 corresponded to areas in macaque brains, although interconnections within the vlFC itself varied between the two species. The team also discovered that the human prefrontal cortex was extensively connected to association areas in the temporal lobe - an area which processes auditory stimuli and language input and output - but significantly less so in macaque brains. They believe these connections are central to our capacity for understanding and generating speech.

Said Professor Rushworth in an Oxford press release, "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".

The team also found one additional distinctively human component: a region named the lateral frontal pole prefrontal cortex. Their experiments show the lateral frontal pole prefrontal cortex is central to the uniquely human abilities to multitask, to strategically plan, and to make option-weighted decisions.

Source: What makes us human?: Unique brain area linked to higher cognitive powers, Press Release, January 29, 2014, Oxford University