Title: Group comparisons in overall linguistic error rate and rate of omissions
Legend: Boys with fragile X syndrome + autism (FXS+ASD) and autistic boys (ASD) had significantly higher rates of omissions, but not overall linguistic errors, relative to mental age-matched and language-matched comparison groups. Nonverbal mental age equivalence was determined by the Leiter Test of Nonverbal Intelligence–Revised for autistic boys and the FXS + ASD group, and chronological age was reported for nonautistic children. MA = mental age; MLU = mean length of utterance. **p < .010
Citation: Maltman, N., Hilvert, E., Friedman, L., & Sterling, A. (2023). Comparison of Linguistic Error Production in Conversational Language Among Boys With Fragile X Syndrome + Autism Spectrum Disorder and Autistic Boys. Journal of speech, language, and hearing research : JSLHR, 66(1), 296–313. https://doi.org/10.1044/2022_JSLHR-22-00078. PMCID: PMC In Progress
Purpose: Expressive language impairments are common among school-age boys with fragile X syndrome (FXS) and autistic boys. Given the high co-occurrence of autism spectrum disorder (ASD) among individuals with FXS, cross-condition comparisons can elucidate the specificity of such impairments as they relate to ASD. Language samples can provide fruitful information regarding individuals’ grammatical skills in less structured formats relative to standardized measures. This study examined grammatical errors produced during a conversational language sample among 20 boys with FXS and co-occurring ASD (FXS + ASD) and 19 autistic boys matched on ASD severity.
Method: Language samples were coded for omissions and errors at the word and utterance levels. Participants’ grammatical errors were also compared to separate mental age-matched and mean length of utterance-matched boys from a reference database.
Results: Boys with FXS + ASD and autistic boys produced similar rates of errors across all categories. Relative to their matched comparison groups, boys with FXS + ASD and autistic boys produced significantly more omissions during conversation.
Conclusions: These findings suggest that omissions may be a unique grammatical marker associated with the ASD phenotype. Further examination of omissions across diagnostic groups would aid in clarifying the specificity of omissions in the language phenotype of ASD.
About the Lab: The Research in Developmental Disabilities Language Lab examines the contributions of both biology and environment in the development of language and cognition in children with developmental disabilities.
Investigator: Audra Sterling, PhD