Apes have same speech area in brain as human
carrie at stayfreemagazine.org
Sun Dec 2 14:46:17 EST 2001
The Independent (London)
November 30, 2001, Friday
HEADLINE: APES HAVE SAME SPEECH AREA IN BRAIN AS HUMANS
BYLINE: Steve Connor Although apes communicate by grunts and
gestures, they possess a brain component that is also critical for
human speech Rex
GORILLAS AND chimpanzees possess a rudimentary speech centre within
their brains that until now was thought to be unique to humans,
scientists have found.
Brain scans of the apes - man's closest living relatives - have
revealed a small, lopsided structure buried in the front part of the
head which in humans is critical for language.
The structure, Brodmann's area 44, is part of the language centre
known as Broca's area, and the scans reveal that it is larger and
more developed in the left half of the ape's brain than in the right
hemisphere - just as it is in humans. Claudio Cantalupo and William
Hopkins, who conducted the study at the Yerkes Primate Research
Centre at Emory University in Atlanta, Georgia, were surprised such a
critical feature within the ape's brain had gone unnoticed.
Unlike humans, apes do not have language, and communicate by grunts
and hand movements. The scientists believe their brains show that the
evolution of language is rooted in a common ape-human ancestor who
lived more than five million years ago.
Mr Cantalupo and Mr Hopkins say in the journal Nature: "The part
possession by great apes of a homologue of Broca's area is puzzling,
particularly considering the discrepancy between sophisticated human
speech and the primitive vocalisations of great apes."
Chimpanzees and gorillas nevertheless share one thing in common with
human communication - they tend to use their right hands when
grunting, which are controlled by the left-side of the brain.
"Our findings suggest that the neuro-anatomical substrates for
left-hemisphere dominance in speech production were evident at least
five million years ago and are not unique to hominid evolution," the
scientists say. "Whatever the function of area 44 in great apes, our
finding that these species show a human-like asymmetry ... indicates
that the origin of asymmetry in language-related areas of the human
brain should be interpreted in evolutionary terms rather than being
confined to the human species."
The latest study follows work published in 1999 showing that wild
chimpanzees have a relatively sophisticated culture in which they are
able to pass on ideas and inventions to their offspring through
teaching and learning.
Other studies at Georgia University's Language Research Centre have
indicated that some chimpanzees can understand simple English
sentences. Panbanisha, a hand-reared female pygmy chimpanzee, can
communicate in basic phrases using a keyboard and a computer screen
displaying symbols that she can press to produce a rudimentary
response to a human voice.
Tech note: Email to my stayfreemagazine.org address often bounces,
for whatever reason. If you email me and it comes back, send it to
stay.free at verizon.net
More information about the Monkeywire