March 22, 2002

Science behind the practice

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Science behind the practice

Stephen Camarata, Ph.D., will soon initiate a multi-disciplinary project to study the genetic, neural processing and neurological structures of speech development. (photo by Dana Johnson)

Stephen Camarata, Ph.D., will soon initiate a multi-disciplinary project to study the genetic, neural processing and neurological structures of speech development. (photo by Dana Johnson)

Stephen Camarata, Ph.D., is applying science to clinical therapy for children with delayed speech and language skills, trying to unravel both the approach that stimulates speech language development most efficiently and, with a new multi-disciplinary study, how the brain responds to learning.

Camarata, professor of Hearing and Speech Sciences in the Vanderbilt Bill Wilkerson Center for Otolaryngology and Communication Sciences and acting director of the John F. Kennedy Center for Research on Human Development, currently is the principal investigator or co-principal investigator for five research projects sponsored by the National Institute for Deafness and Other Communication Disorders that total about $2.2 million annually in direct funds.

Each year, 200 to 300 Tennessee children, and another 100 or so from out of state, come to the Child Language Intervention Program, or CLIP, and the Scottish Rite Child Disorder Center, currently located in the Bill Wilkerson Center building on 19th and Edgehill. The program is open to any child whose speech is delayed, regardless of possible diagnosis.

“There’s a whole gamut of causes that relate to speech and language delays,” Camarata says. “We look at the child’s deficits and design a speech and language program to fit that child.”

Some children fit into one of the ongoing research protocols, but data are collected on every child for a speech-delay database.

Camarata’s main emphasis is developing treatment techniques that work best to help children overcome various speech delays by testing several well-established learning models.

One, designed by Keith Nelson, a collaborator at Penn State University, hypothesizes that for a child to learn to speak, certain elements must be in place, namely attention, motivation, perceptual salience and memory. Success depends on recognizing the differences between children that develop normally and children with developmental delays, and adapting the learning process to accommodate the deficiency. That, Camarata says, makes the most efficient use of the child’s abilities to learn.

An initiation-based model suggests that the best opportunity for children to learn is when they initiate communication. One characteristic of severe language delay is social avoidance, including communication. “These children lack motivation to speak,” Camarata says. So this technique focuses on recognizing the child’s cue to speak, even if it is slight, taking advantage of his “residual motivation” from the initiation and expanding on it. “If the child initiates, then you know you have his attention and that he’s motivated and his short-term memory is likely to still be active,” Camarata says.

A transactional model has everyone in the child’s learning environment— parents, teachers, therapists—interacting with the child in the same way. For instance, if a child has difficulty finishing the ends of words, he might say “ball roll.” That’s a cue for parents to interact, responding with “ball rolling,” so that the child learns word endings.

Some children with developmental disorders need more exposure, so a repetition model might fit best. Whereas children with normal speech development might learn a new word after two or three exposure to it—associating a name to an object “it might take 100 to 200 exposures” for children with severe delays to learn it—but he can learn in the same way if there are sufficient presentations, Camarata says.

A new study goes beyond technique to understand the genetic, neural processing and neurological structures associated with speech development.

“We’re trying to figure out what it means biologically,” he says. “We’re interested in what happens when a parent models and the child learns. What are the neurological correlates?”

The project includes a team of Vanderbilt collaborators, including faculty from genetics, special education, auditory research, neurobiology and imaging specialists. Functional MRI will study older children, those able to lie still. Younger children will be studied with an electroencephalograph-type device.

“This is very exciting because we’re on the frontiers of scientific discovery to see how our interaction with our children facilitates biological development,” Camarata says. “In addition, we can begin to bring objective, biological measures to the intervention process.”