College of Medicine & Veterinary Medicine

Chimp study reveals how brain’s structure shaped evolution

Chimpanzee brains may be more different from those of humans than was previously thought, according to new research that sheds light on our evolution.

A chimp scratching its head

The pattern of asymmetry in human brains could be a unique feature of our species and may hold the key to explaining how we first developed language ability, experts say.

Researchers led by the University of Edinburgh studied images from an existing bank of chimpanzee brain scans held in the US.  Comparisons were then made with the brains of humans who were scanned using similar equipment – known as magnetic resonance imaging (MRI) – and identical experimental procedures.

Chimpanzee brains were shown to be made up of equal halves, or hemispheres, whereas in human brains a subtle twist was present. This asymmetry was seen in humans – but not chimpanzees – with the left hemisphere longer than the right.



Language ability has been linked to areas within the left hemisphere of the brain and has also been associated with asymmetry.

The research sheds light on how humans developed skills for language, researchers suggest. A new study of particular brain areas related to language using the same image bank could aid understanding of this.

The study was published in the journal Neuroimage. It was carried out in collaboration with researchers at the University of Oxford, as well as in China and the US.


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Edinburgh Imaging

Original article