Is language an acquired skill, like telling time or riding a bike? Is it nurtured from infancy by conscientious parents or does nature gradually craft a child’s babble into basic sentences?
Many speech and language researchers now believe the human ability to learn and use language is not simply an extension of general intellectual abilities, but an evolutionary trait deeply rooted in the biology of the species.
“Our capacity for language is biologically determined in the organization of our body, mind and brain,” said Stephen Anderson, the Dorothy R. Diebold Professor of Linguistics at Yale University and an organizer of “The Language Organ: The Bases of Human Language in Human Biology,” a seminar at last month’s meeting of the American Association for the Advancement of Science (AAAS).
Casting wider nets
Scientists don’t completely understand how the human brain translates thoughts into words at lightning speed, but they have identified the brain’s left hemisphere as the command center for language. Its partner, the right brain, regulates visual-spatial functions, such as searching for Waldo or finding your way around campus.
As researchers pursue a deeper understanding of language’s biological underpinnings, some are casting wide nets to capture information about other forms of communication, including sign languages.
Karen Emmorey, Ph.D., a professor of speech, language and hearing sciences in SDSU’s College of Health and Human Services, is among the world’s leading sign language researchers.
Her body of work examining what sign languages reveal about the nature of human language, cognition and the brain has earned her the title of Albert W. Johnson Research Lecturer for 2013, SDSU’s highest research honor.
A visual language
“Studying sign language allows us to look at human language ability in a broader way and ask questions that can’t be answered by considering spoken language alone,” Emmorey said.
Because signs like those meaning “to write” or “to hammer” resemble the action described, many people view sign language as simply a comprehensive set of gestures. But those who’ve created poems in sign language, or struggled to remember a sign that was just on the tips of the fingers would argue it’s much more.
Emmorey seconds that argument. Her research—extending over 25 years—demonstrates that sign language is produced and comprehended in the same areas of the brain as spoken language, and that the brain can distinguish between signs and mere gestures.
Emmorey’s insights have also contributed to the development of clinical practices that address communication disorders related to brain injury and to the improvement of educational practices for deaf and hard-of-hearing individuals.
Research on bilinguals
Director of SDSU’s Laboratory for Language and Cognitive Neuroscience, Emmorey heads a group of international researchers—both hearing and deaf—studying a multitude of topics related to language and the brain.
Currently, the lab is comparing bimodal bilinguals (those who are fluent in both a signed and a spoken language) with mono-modal bilinguals (those who speak two languages).
While mono-modal bilinguals must suppress one language while speaking another, bilingual bimodals are able to code-blend, rather than code-switch, and employ their two languages simultaneously.
“Our research shows that using code-blends doesn’t slow you down,” Emmorey said.
Emmorey’s work is supported by the National Science Foundation and the National Institutes of Health. Since joining SDSU in 2005, she has directed, as principal investigator, more than $10 million in federal grant funding, including $2.5 million for this fiscal year.
She has also presented at four consecutive annual AAAS meetings, considered forums for the announcement and dissemination of cutting edge research.
The 23rd annual Albert W. Johnson Research Lecture is scheduled for Friday, March 15, at 3 p.m. in room 201 of the Arts and Letters Building. The lecture is free and open to the public. Seating is available on a first-come, first-served basis.