August 13, 2011

Prefrontal Cortex Development Of Humans, Chimps Contrasted

While both humans and chimpanzees start out life with key portions of their brains underdeveloped, the rapid growth in these cognitive and decision-making areas that occur in human children are not characteristic of young chimps, a new study has discovered.

According to Sindya N. Bhanoo of the New York Times, researchers from Kyoto University in Japan discovered that both species "start out with undeveloped forebrains" but that "the human brain increases in volume much more rapidly early on."

"The growth is in a region of the brain known as the prefrontal cortex and is part of what makes humans cognitively advanced compared with other animals, including the chimpanzee, our closest relative," Bhanoo added.

Zoologist Tetsuro Matsuzawa and his colleagues used MRI scans on three young chimpanzees over a period of about six years, starting when they were six months of age, the New York Times reported said.

They then compared those scans with similar ones taken of human infants and children, and discovered that "the white matter in the prefrontal cortex of chimpanzees does not grow as rapidly as it does in humans."

Their findings have been published in the journal Current Biology.

According to an August 11 press release from Cell Press, publishers of Current Biology, the researchers observed that both chimps and humans "enjoy close relationships between infants and adults, as indicated by smiles and mutual gazes," but that the "the greater prefrontal expansion in the human brain may contribute to the development of language, complex social interaction and other abilities that are unique to us."

Matsuzawa and his team have announced their intention to continue their work in the field of brain development as both humans and chimpanzees enter adulthood. They plan to continue studying their three chimpanzee subjects, which are all currently around 11 years of age and have since entered puberty.


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