Columbia, Mount Sinai Scientists Find Region That Controls Language Identical In Both Species; Chimps May Use Gestures To Communicate
Researchers at Mount Sinai School of Medicine, Columbia University and the National Institutes of Health have found that a region of the brain thought to control language is proportionately the same size in humans and chimpanzees, disproving a theory that the brain section was enlarged only in humans.
The discovery, reported in the Jan. 9 issue of the journal Science, throws into question the role of the planum temporale, a part of the brain's parietal cortex that is located beneath the parietal cortex. The planum temporale of the left hemisphere is normally larger than in the right hemisphere in humans, but 94 percent of the chimpanzee brains studied demonstrated the same asymmetry.
Could the research result be interpreted to mean that chimpanzees have some kind of language? "I don't think they have a language, but I do agree that they have some kind of communication system that might be more complex than we have heretofore thought," said Ralph Holloway, professor of anthropology at Columbia and co-author of the Science paper. He believes chimps may converse using a sophisticated array of facial, body and hand gestures, perhaps augmented with grunting or other vocalizations.
Patrick Gannon, assistant professor and director of the Paleoneurology
Research Laboratory in the Department of Otolaryngology at Mount Sinai, first
suspected that chimpanzee brains might show the same asymmetry as those of
humans. He sought the collaboration of Professor Holloway, who then assisted
in measuring the planum temporale, which is not an obvious anatomical feature,
on his collection of 18 chimpanzee brains. The Columbia anthropologist conducts
comparative neuroanatomical studies on the chimpanzee brains in order to better
understand evolution of the human brain.
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