Genetic Disorder May Offer
Clues to Language Acquisition
PHOTO: WILL KIRK
People with a rare genetic condition called Williams syndrome are a study in contrasts. Their IQs place them in the mildly to moderately retarded range, yet they are generally strong readers who also use spoken language in often sophisticated ways. They are sociable and have an affinity (some call it a “gift”) for music. Yet many people with Williams cannot tie their own shoes or distinguish right from left, and if you ask them to copy a simple drawing of a bicycle, the wheels, chain, seat, frame, and pedals appear in disconnected bits all over the page.
It’s little wonder, then, that the paradoxes inherent in the syndrome, which afflicts one in every 20,000 children born in the United States, fascinate Barbara Landau, the Dick and Lydia Todd Professor of Cognitive Science at Johns Hopkins.
Landau recently received a five-year, $1.7 million grant from the National Institutes of Health to study the cognitive problems associated with Williams sydrome.
Landau finds Williams syndrome compelling because it suggests that genetic material affects not only microscopic processes in the brain, but also higher-level functions, such as how people think and process information.
“This is very important as we go forward in trying to understand the relationships among gene, brain, mind, and behavior,” she says.
Williams syndrome, first identified in 1961, results when a chunk of genetic material goes missing—for reasons that remain mysterious—from chromosome 7.
Of particular interest to Landau was that people with Williams combine normal language acquisition with an often severely impaired sense of spatial knowledge/relationships.
“For me, the key questions have always been: How do we learn language? How is it supported by our knowledge of objects and events around us, their spatial relationships, and so on?” says Landau.
Most theories of language acquisition assume that children learn language, at least in part, as they grow to understand things non-linguistically. They learn the word “ball” by hearing others say it and by holding the ball and seeing it bounce on the floor and ricochet off the wall.
If this is true, Landau wondered, then how on Earth do people with Williams syndrome, whose brains are genetically programmed not to understand spatial relationships, manage to talk about them? How do they learn the names for objects and the words to describe relationships between those objects?
Those intriguing questions have kept her busy for a decade. Landau’s work, in turn, has made her Ames Hall lab something of a mecca for parents of children with Williams syndrome, who come from neighboring states to have their children participate in research studies.
“These parents are desperate to really understand this syndrome,” Landau says. “Until recently, Williams syndrome often went undiagnosed, and even when it was diagnosed, children were put into ‘special ed’ classes at school. The parents are very interested in getting basic research done to understand what’s wrong, as well as what’s right.”
Landau’s research has shown her, among other things, that the rules governing how human beings learn about the world, in a cognitive sense, are very powerful indeed.
“Even though adults with WS might be severely impaired at some spatial tasks, their performance is still—at a very detailed level—very much like that of a normally developing person at some age,” Landau says, noting that people with Williams may be slower to develop cognitive abilities or not develop beyond a certain point. The fact that a person with Williams can develop such abilities and knowledge at all, she says, is “a testimony to the power of the human mind.”
Though Landau’s research promises to provide insight into those with Williams syndrome—an understanding that could lead, eventually to more effective treatment—it also has implications for understanding human cognition and language acquisition in general, she says.
—Lisa De Nike