Disruptions in Spontaneous Language in HFA: Indicators of Linguistic Processing Challenges

Background: The language challenges of high-functioning older adolescents and adults with autism are difficult to assess. Few standardized language measures are available for this age/population and are primarily measures of narrow areas such as lexical knowledge. Samples of connected speech are generally analyzed for pragmatic features such as conversational turns. Narrative ability has been studied in children with HFA (Losh & Capps, 2003) but the focus has been on story grammar elements and grammatical complexity. Dollaghan and Campbell (1992) suggest the analysis of utterance disruptions during spontaneous language samples as a way to quantify speech production difficulties related to information-processing demands. This analysis may be useful for characterizing the language production of adults with HFA.

Objectives: To analyze spoken language samples of adolescents and adults with autism as compared to age and IQ-matched controls to determine if differences occur in measures considered to be indicators of problems with information processing.

Methods: Participants were 15- to 35-year old individuals with HFA (n=23) and typically developing controls matched for age and IQ, with Verbal IQs ³ 85. Autism diagnosis was established with the ADOS and ADI-R, and confirmed by expert clinical impression. A narrative language sample was collected using the “Create a Story” task from the ADOS. The language sample was transcribed using the Systematic Analysis of Language Transcripts (SALT) transcription format (Miller & Chapman, 2000). Measures of spontaneous speech including number of words, mean length of utterance (MLU), number of different words (TTR), number of mazes and abandoned utterances, and number of different word roots (NDWR) were computed using SALT-based analysis. Within-utterance “disruptions” were identified (based on the taxonomy of Dollaghan & Campbell, 1992) as an indicator of the individual’s difficulty with language production.

Results: Samples have been transcribed for 23 older adolescents and adults with HFA. Transcript reliability was established (.99) with another graduate student. Language sample collection is ongoing for the matched control group. Initial analyses indicate a wide range of verbal fluency in this group with HFA. Total number of words produced ranged from 33 to 461 (Mean = 144.87; SD 92.62). The participants produced an average of 5.75 (SD 4.31) disruptions per 100 unmazed words (compared to an average of 5.31 (SD1.82)] for Dollaghan & Campbell’s group of 10 typically developing school age children). Four of the participants had clinically significant rates of disruptions (11.49, 11.51, 13.24, 18.09). Further analyses will be reported and comparisons will be made to an age and IQ-matched control group.

Conclusions: Some high-functioning individuals with autism have difficulty with the production of spoken language that may be related to information processing demands. These problems go beyond the diagnostically significant ones in pragmatic language. Measurement of disruptions during spontaneous speech production may be clinically useful for the characterizing the language production challenges of these individuals.