健康英语新闻:U.S. scientists identify new brain speech processing center

WASHINGTON, Jan. 30 (Xinhua) -- The part of the brain used for speech processing is in a different location than originally believed, according to a U.S. study released online Monday in the Proceedings of the National Academy of Sciences.

Scientists have long believed that human speech is processed towards the back of the brain's cerebral cortex, behind auditory cortex where all sounds are received -- a place famously known as Wernicke's area after the German neurologist who proposed this site in the late 1800s based on his study of brain injuries and strokes.

But, now, research that analyzed more than 100 imaging studies concludes that Wernicke's area is in the wrong location. The site newly identified is about three centimeters closer to the front of the brain and on the other side of auditory cortex -- miles away in terms of brain architecture and function.

The finding means that "textbooks will now have to be rewritten, " says the study's senior author, Josef Rauschecker, a professor in the department of neuroscience at Georgetown University Medical Center. "We gave old theories that have long hung -- a knockout punch."

The finding matters, Rauschecker says, because the new location of Wernicke's area matches that recently found in non-human primates, suggesting the origins of language between monkeys and humans is closer than many have thought.

Knowing that Wernicke's area is in the front of the auditory cortex could also provide clinical insights into patients suffering from brain damage, such as a stroke, or in disorders in speech comprehension. "If a patient can't speak, or understand speech, we now have a good clue as to where damage has occurred," he says.