Brain Area Unique to Humans Helps You Make Decisions

By comparing human and monkey brains, researchers from Oxford University have discovered a brain area in the frontal cortex that is unique to humans. The region is thought to be involved in some of our most advanced cognitive functions such as decision-making and planning. Monkey brains are often used as models for human brains in psychological research and we have become used to highlighting the similarlities between them. There are, however, obvious behavioural differences between monkeys and humans, which the researchers suggest could derive from this newly discovered brain area.

In order to compare human and monkey brains, the research group, led by Dr. Matthew Rushworth, performed two types of brain scans on 25 macaque monkeys and 25 humans. The first type of scan, a resting-state functional MRI, was used to test the connections between regions within the ventrolateral frontal cortex (vlFC, known to be involved in higher level cognitive functions such as language and decision-making) and between the vlFC and other areas of the brain. The second type of scan was used to compare the structure of the human and monkey brains.

The monkey and human brains were fundamentally similar in most respects. The researchers were able to identify 12 regions within the vlFC of humans. 11 of these regions were strikingly similar to regions in the monkey vlFC both with respect to structure and connectivity. The 12^th region, however, appeared to be uniquely human. The researchers also observed significantly more connections between auditory brain areas and the vlFC in humans, a discrepancy which might account for our unparalleled capacity for understanding and producing language.

What is most suprising about the discovery is how small the brain differences are, given how remote we seem from the monkey. It seems that small differences in the brain are able to give rise to very large differences in behaviour.