Relationship between Executive Function and Language Skills in Youth with Autism Spectrum Disorder
Objectives: We examined relative impact of language ability to predict variability in EF skills across a sample of youth with ASD.
Methods: Twenty-five youth with ASD, aged 6 to 16 years (M=10 yrs) completed a measure of receptive language, Peabody Picture Vocabulary Test-Fourth Edition (PPVT), and a measure of their expressive language skills, Expressive Language Index (ELI) from the Clinical Evaluation of Language Fundamentals- Fifth Edition. Set-shifting, working memory and inhibition were each assessed using subtests from the NIH Toolbox and Weschler Intelligence Scale for Children-5th Edition. Additionally, parents completed the Behaviour Rating Inventory of Executive Function- Second Edition as a measure of participants’ EF-related behaviour.
Results: To examine how well language ability predicted EF, we created regression models of EF using our language measures as predictors. Our first model explained 61.1% of the variance in our working memory task with ELI making the only unique contribution to the variability in scores. In contrast, our second model predicted 36.2% of the variance in inhibition with PPVT-4 making the only unique contribution. Finally, while the third model explained 20.4% of the variance in our set-shifting task, neither ELI nor PPVT made unique contributions. However, language did not predict EF when the parent-reported measure of EF was used in the model.
Conclusions: Our results lend further support to the hypothesis that language ability predicts EF skills for youth with ASD. This suggests that youth with ASD are capable of using language in service of EF processes. While many students with ASD may not have strong EF skills (Demetriou et al., 2017), these findings suggest that they seem to use language in EF process in the same way that TD kids do. More importantly, this work may suggest that parents, clinicians and educators may need to focus on strengthening the language-based strategies used during EF processes to support the development of these skills.