Communication impairment is one of the core features of autism spectrum disorder (ASD), yet we know very little about the communicative profile of high-functioning (i.e. those without intellectual disability; HFA) adults with ASD. In children with HFA, pragmatic dysfunction, defined as difficulty in the appropriate and social use of language, persists even when scores on traditional tests of language competence are within normal limits (Landa, 2000, Volden & Phillips, 2010). Functionally, pragmatic impairment negatively influences the establishment of friendships (Landa, 2000). One difficulty is finding measures of language competence and pragmatic impairment that are appropriate for adults. The pragmatic subtests (Pragmatic Judgment, Non-Literal Language) from the Comprehensive Assessment of Spoken Language (CASL; Carrow-Wollfolk, 1999) may be useful (Reichow, et al., 2008), but to date, the CASL has not been used with the adult HFA population. In addition, Whitehouse & Bishop (2009) have recently developed a checklist, completed by an informant that knows the affected adult well, called the Communication Checklist – Adult (CC-A) and found that it was able to identify adults with communication disorders. No studies have yet been conducted using these measures on young adults with ASD.
This pilot study examines communicative performance in adults with HFA using a battery of language and communication measures. Performance on the CASL and the CC-A is expected to reveal deficits in pragmatic skill while participants may or may not demonstrate difficulties in language syntax or vocabulary.
Five adults (18- 30 years) with confirmed diagnoses of ASD based on the Autism Diagnostic Observation Schedule (ADOS; Lord et al.,2003) and performance IQs above 80 based on the Weschler Abbreviated Scale of Intelligence;( WASI; Weschler, 1999) were given a battery of language tests. Syntax and vocabulary abilities were determined using subtests from the Test of Adolescent and Adult Language - 4 (TOAL-4; Hammill, et al., 2007). Pragmatic abilities were measured using pragmatic subtests from the CASL (Carrow-Wolfook; 1999) and the CC-A.
As expected, mean standard scores on syntactic (10.2, 8.4) and semantic (11.6, 8.4, 8.0) subtests from the TOAL were all within the average range (10 + / - 3). Surprisingly, mean performance on pragmatic subtests from the CASL (96, 86) were also within the average range (100 + / - 15). Mean scaled scores from the CC-A, however, indicated abnormality (scaled scores < 6) on the Pragmatic Skills (mean scaled score = 5.2) and Social Engagement (mean scaled score = 3.2) subscales.
For this pilot sample of adults with HFA, neither the conventional standardized language measures nor the CASL detected communicative impairment. This contrasts sharply with results from the CC-A. Whitehouse & Bishop (2009) note that impaired scores on 2 or more subscales are indicative of communication difficulties that will influence everyday life. If these results are confirmed in larger studies, clinicians should include the CC-A in the evaluation of communicative profiles of adults with ASD in order to capture the kinds of communicative difficulties that may influence a person’s ability to participate in the community.
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