Grant Award Funds Research on Language Impairment in Autism

06/15/2007

Language impairment (LI), defined by a reduced cognitive capacity for speech and non-verbal communication, may be the result of fundamental deficits within the computational linguistic system of the brain, according to anew study.

A language-impairment diagnosis is a common feature associated with autism and the autism spectrum disorders, which appear to be primarily genetic and affect approximately one in 150 children.

The severity of autism-associated LI can vary from child to child, ranging from undetectable to speech-debilitating. Degrees of LI are also observed in children who are not autistic, and it is unknown if LI's origin is shared between autistic and non-autistic children. Addressing this possibility could dramatically improve LI diagnosis and lead to more rational directions in autism research and therapy.

Timothy P.L. Roberts, Ph.D., Department of Radiology, recently received a major grant award from the National Institutes of Health to evaluate LI in the pediatric population. As part of this $1.25 million, 5-year award, Dr. Roberts hopes to identify and differentiate between the electrical "signatures" that underlie language impairment in the brains of autistic children and unaffected children. Comparisons of autistic and non-autistic children with normal speech will provide additional insight into the electrophysiological nature of LI.

Magnetoencephalography (MEG) provides real-time visualization of electrical brain activity with high temporal and spatial resolution. In Dr. Roberts' clinical studies, participants will be exposed to various auditory or speech stimuli while their brain function is monitored. Changes in the electrical brain signatures in response to these stimuli will allow for in-depth analyses of brain activity between groups.

"It is clear that language impairments we see behaviorally may in part stem from timing and communication difficulties between neurons in the brain; MEG provides a unique technology to track those signals within the brain, with real-time speed," says Dr. Roberts.

Dr. Roberts' research will also examine the correlation between neuronal white matter maturation and electrical brain signatures in the context of childhood development. Deficient white matter development could be part of the mechanism of reduced or delayed brain activity and the onset of LI.

Understanding the magnetoencephalographic responses of the autistic and non-autistic brain to auditory stimuli could provide a novel diagnostic tool for LI and greatly enhance our understanding of language cognition and physiology. This understanding may also provide insight into the similarities and differences between the brains of children with autism spectrum disorders and other neurodevelopmental disorders.