Non-word repetition in adolescents with Specific Language Impairment and Autism plus Language Impairments: A qualitative analysis
Section snippets
Literature review
Over the past few years there has been vigorous debate over the relationship between Specific Language Impairment (SLI) and Autism Spectrum Disorders (ASD) (Williams, Botting, & Boucher, 2008). While standard diagnostic criteria differentiate these two disorders, recent clinical data suggest that the boundaries may not be so clear. According to the Diagnostic and Statistical Manual of the American Psychiatric Association (DSM IV: 2000) children with SLI should not present with a Pervasive
Participants
A total of 16 participants with ALI, and 11 participants with SLI were selected from a cohort of individuals with Special Educational Needs who had been assessed during the Special Needs and Autism (SNAP) Project (Baird et al., 2006). A diagnosis of autism was made on the basis of ICD-10 criteria (World Health Organisation, 1993) using information from the Autism Diagnostic Observation Schedule (ADOS: Lord et al., 2000), Autism Diagnostic Inventory – Revised (ADI-R: Lord, Rutter, & Couteur, 1994
Analysis of error rates based on phonemic coding scheme
Error rates by Group are reported in Table 2, and plotted in Fig. 1. A Levene's test comparing the SLI and ALI groups on all-or-none error rates yielded a non-significant p-value (p = 0.338) thereby indicating homogeneity of variance. A one-way ANOVA was run investigating the effect of Group on error rates derived from the phonemic transcription, followed by a post hoc Tukey's test. There was a significant effect of Group on all-or-none error rate (F(2, 43) = 14.0, p < 0.001**, partial η2 = 0.39), with
Discussion
The study replicated and extended the findings of Whitehouse et al. (2008), with a significantly stronger effect of syllable length in the SLI group than the ALI group. In addition, when errors were counted on a phoneme-by-phoneme basis, the participants with SLI performed significantly poorer overall than the ALI participants. Further qualitative analyses did not uncover other robust differences between the clinical groups. While the participants with SLI tended to make more errors affecting
Acknowledgments
The authors wish to thank Autism Speaks/The National Alliance for Autism Research for their generous funding; the parents/guardians and individuals who participated in the study; and Susie Chandler, Abigail Davison-Jenkins, Ann Ozsivadjian, and Vicky Slonims for their help in screening the participants with autism spectrum disorders (ASD). The first author wishes to thank Colin Bannard at the Max Planck Institute, Leipzig, Germany, for explaining the concept of the Levenshtein Distance; and
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