Early failure to pay attention to faces, speech may influence later development in autism
BOSTON – A leading scientist trying to understand and treat autism suspects that a failure to engage in such normal social activities as looking at a parent's face or listening to speech sounds early in life may help explain the profound impairments in social and language development shown by most children with the disorder.
Geraldine Dawson, director of the Autism Center at the University of Washington, will deliver the keynote address today at the 4th International Meeting for Autism Research being held at the Marriott Boston Copley Place. The meeting will attract leading scientists from around the world, who will discuss research on genetic factors, brain research, new treatments and potential environmental factors involved in the development of autism.
Dawson, also a UW psychology professor, said her team has begun testing a new intervention program for toddlers with autism that not only has a dual focus on language and cognitive development but also promotes the emotional relationship between a child and other people.
"We are examining whether this very early intervention that focuses on social engagement alters the course of development," she said. "As part of our outcomes, we will be examining the child's brain responses to social stimuli. We hope to find that our intervention not only affects behavior but also alters the trajectory of early brain development toward a more normal one."
Most interventions for children with autism are designed for children of preschool age or older, and there are few such programs for toddlers. The UW program, however, treats children as young as the researchers can reliably diagnosis with autism, some just 18 months of age. The program was designed with the assistance of Sally Rogers, a professor of psychiatry at the University of Colorado Health Sciences Center.
The intervention program is intensive, running 25 to 30 hours per week over a two-year period. It involves cognitive and motor skills, and also has a strong focus on emotional and social relationships, Dawson said. The intervention includes such things as children playing games that encourage social activities with their parents or a therapist. The games are modeled after typical parent-infant games, such as patty-cake, that focus on shared communication and enjoyment.
Previous studies by Dawson and her colleagues have shown that preschool-age children with autism do not show typical brain responses to faces and speech sounds, but they do have normal responses toward objects. By 7 or 8 months of age a typically developing a baby's brain waves register differences between two speech sounds and between familiar and unfamiliar faces. Children with autism, however, do not show such differences at 3 and 4 years of age.
Other research has shown that normal development of the brain systems involved in speech and face perception requires early stimulation. Dawson said that a study of American infants exposed to the sounds of Mandarin Chinese that was led by colleague Patricia Kuhl, co-director of the UW's Institute for Learning and Brain Sciences, has important implications for understanding autism.
In that study, groups of 9-month-old infants were shown exactly the same material in Mandarin. One group had the material presented in person by a Mandarin speaker with whom they could interact socially. The other group saw the speaker only on a videotape. Only the brains of children exposed to the speaker with whom they could interact socially learned to distinguish different sounds in Mandarin.
Similarly, children with autism are not able to distinguish English sounds, according to Dawson.
"For speech perception to develop normally, a baby not only must hear speech sounds, but the baby also must be actively engaged in social interaction that involves speech. In other words, the emotional and social relationship is critical for normal social and language brain development to occur. The infant or toddler with autism appears to lack a normal preference or interest for social and language information and fails to actively attend to other people," she said.
Dawson hopes that by teaching toddlers with autism how to interact socially, this will influence the way the children's brain process language and facial information.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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