PRIMATE SCIENCE RESEARCH HIGHLIGHT
"Chimpanzee, human communication controlled by similar structure"

by Tonia Scantlen, editorial intern, Wisconsin Regional Primate Research Center

The area of the chimpanzee brain generating ape "language" is exactly the
same in structure and size asymmetry between the left and right hemisphere
of the brain as the communications oriented part of the human brain, a
recent study reveals. The research, conducted by Dr. Patrick Gannon of the
Mount Sinai School of Medicine Department of Otolaryngology, adds further
evidence to the argument that communications skills in chimps and humans
are highly sophisticated, albeit expressed in different ways.

The region, named the planum temporale (PT), seems to process communicative
information regardless of its form, be it gestural/visual, vocal/auditory
or possibly any other form. The PT is also involved with behaviors presumed
to be distinctly and uniquely human such as musical talent and handedness,
as well as communication-related  disorders such as schizophrenia and
dyslexia.

Chimpanzees are our closest relatives, yet we have different ways of
communicating. Chimpanzees use a wide array of visual gestures of the face
and body, clap, pick at each other, tickle and issue utterances to each
other. Humans clearly use more complex communications that are related to
our more derived cognitive abilities. But Dr. Gannon believes that the
neurophysiology behind chimp communication,  though outwardly different
from ours, is still quite sophisticated and more similar to ours than we
think.

Dr. Gannon's research, conducted through gross anatomic, MRI and
immunocytochemical analyses, indicates that the PT may have already been a
fundamental part of the brain of the common ancestor shared by humans and
chimps around 8-14 million years ago. Rather than evolving only in humans,
he argues that the PT continued to evolve in both species, but to
accommodate different communications challenges. Humans expanded their
territories and encountered new and different experiences that demanded
novel communication skills.

Dr. Gannon's research may lead to new insights into the origins of human
language and speech, including the organization of language-related areas
of the brain and their design and evolution.

Next, Dr. Gannon plans to monitor the activity of "language" regions in the
brain of chimpanzees and bonobos with PET scans, as the ape responds to
communication-related tasks. If the PT becomes activated on the left
hemisphere, the part of the brain that controls communication, proof of its
role in language outside of the human realm will be realized, and the doubt
some scientists harbor about Dr. Gannon's findings will be erased.

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For more information, please contact Patrick J. Gannon, Ph.D., at
p_gannon@smtplink.mssm.edu.

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References:

http://www.nsf.gov/sbe/nuggets/021/nugget.htm

Gannon, P.J., L. Holloway, D.C. Broadfield, and A.R. Braun. 1998. Asymmetry
of chimpanzee planum temporale: Humanlike pattern of Wernicke's brain
language area homolog. Science (January 9). 279:220-222.

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Primate-Science Research Highlights appears every other week and focuses
broadly on research involving non-human primates. Coverage includes
biomedicine, behavior, conservation and veterinary science. Please
submit highlights for this column to Larry Jacobsen, Primate-Science Research
Highlights editor, at jacobsen@primate.wisc.edu. A 300-word limit and
lay-language style are recommended. Primate-Science Research Highlights are
supported by a grant from the National Institutes of Health,
National Center for Research Resources.  Copyright 1999,
Wisconsin Regional Primate Research Center. No portion of this highlight
may be copied or redistributed without the consent of the editor.

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