Language dysfunction is one of the cardinal characteristics of the autism spectrum disorders. Less than 50% of autistic children are verbal, and most of these demonstrate significant pragmatic impairments that compromise the functional quality of verbal skills. This project seeks to better define the neurobiological correlates of language diversity within the autism spectrum disorders. Several recent studies of non-autistic children with language impairments suggest that many difficulties in language can be traced to fundamental deficits in auditory processing, especially with respect to the processing of rapidly changing linguistic information. This study seeks to determine the extent to which basic auditory processing problems are associated with language dysfunction in children with autism. As part of the study we will also investigate the extent to which epileptiform activity in auditory and language cortices may be contributing to language compromise. Behavioral and psychophysical measures of language and auditory functioning will be obtained, as will electrophysiological (EEG and MEG) measures of auditory and language processing. We will also acquire structural MRI data that will be subjected to quantitative analyses, especially with respect to volumetric asymmetries for Broca's and Wernicke's areas. Multiple correspondence analyses will be used to examine the inter-relationships between functional, structural, and behavioral measures. In order to capture the full range of language variability in autism, data will be obtained from five groups of children with autism spectrum disorders. The specific ASD groups are (A) non-verbal autistic children, (B) autistic children that are verbal but with non-functional language as indexed by a lack of two word phrases, (C) autistic children with functional but impaired language [CELF<81], (D) autistic children with relatively normal functional language [CELF>81], and (E) children with Asperger's syndrome and relatively normal functional language. We will also collect data from two comparison groups -- normal control children and children without autism but with specific language impairment Project Narrative;Autism Spectrum Disorders are a neurobiological condition characterized by impaired language and social skills.
Language abilities are one of the best predictors of long-term outcome, but these can be highly variable in the condition, some children with autism showing near normal language abilities while others are completely non-verbal. This project uses multiple brain imaging techniques to evaluate how basic auditory [hearing] skills impact language development and ability. By better understanding the biology of language deficits, better therapeutic interventions can be developed.
