ScienceDaily (Nov. 9, 2009) — Your ability to make sense of Groucho's words and Harpo's pantomimes in an old Marx Brothers movie takes place in the same regions of your brain, says new research funded by the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health.

Scientists have known that sign language is largely processed in the same regions of the brain as spoken language. These regions include the inferior frontal gyrus, or Broca's area, in the front left side of the brain, and the posterior temporal region, commonly referred to as Wernicke's area, toward the back left side of the brain. It isn't surprising that signed and spoken language activate the same brain regions, because sign language operates in the same way as spoken language does -- with its own vocabulary and rules of grammar.

Current thinking in the study of language is that, like a smart search engine that pops up the most suitable Web site at the top of its search results, the posterior temporal region serves as a storehouse of words from which the inferior frontal gyrus selects the most appropriate match. The researchers suggest that, rather than being limited to deciphering words alone, these regions may be able to apply meaning to any incoming symbols, be they words, gestures, images, sounds, or objects. According to Dr. Braun, these regions also may present a clue into how language evolved.

"Our results fit a longstanding theory which says that the common ancestor of humans and apes communicated through meaningful gestures and, over time, the brain regions that processed gestures became adapted for using words," he said. "If the theory is correct, our language areas may actually be the remnant of this ancient communication system, one that continues to process gesture as well as language in the human brain."

http://www.sciencedaily.com/releases/2009/11/091109173412.htm