Differences in Receptive and Expressive Language Abilities in Children with ASD

Background:  Autism spectrum disorders (ASD) are a set of complex developmental disabilities characterized by both receptive and expressive language deficits.  It is important to understand the heterogeneous nature of these deficits because they are often among the first symptoms observed and play a critical role in the assessment and differential diagnosis of ASD.  Additionally, the degree of language impairment is a key component in predicting a child’s prognosis.  Some evidence suggests that when compared with children with other language disorders, children with ASD show more severe receptive language deficits.  Further understanding of the different types of language impairments demonstrated, their trajectories, and the measures used to assess them should advance the diagnosis and treatment of children with ASD.

Objectives: The purpose of this study is to investigate the relationship between receptive and expressive language deficits and ASD symptomatology across multiple measures.  The study compared children who were diagnosed with an ASD and children with other clinical impairments (i.e. language delays and developmental delays).

Methods: The current sample consists of 28 children (age 2 to 7, mean = 53.39 months, SD = 13.48) who received a comprehensive ASD evaluation using both the ADI-R and the ADOS.  Additionally, each child’s language abilities were assessed using the Preschool Language Scale (PLS-3 or PLS-4).  Seventeen of these children were diagnosed with an ASD (15 male, 2 female).  The clinical comparison group was comprised of 11 children (6 male, 5 female) who were not diagnosed with ASD.  Data collection is ongoing and it is anticipated that there will be at least 25 participants in both groups.  None of the participants in this study had hearing impairments or co-morbid psychiatric diagnoses.

Results: Preliminary results indicate that there were significant group differences in receptive language abilities dependent upon whether or not a child had an ASD.  Specifically, children with ASD had significantly lower receptive language scores on the Preschool Language Scale than children in the clinical comparison group, (t = 1.82, p < .05).  In contrast, there were no significant differences between the two groups for expressive language scores, (t = 0.25, p > .05). Additional analyses were conducted to determine if there were differences in receptive and expressive abilities for each group.  The children with ASD scored significantly higher on expressive language compared with receptive language, (t = -3.99, p < .001), whereas the clinical comparison group showed no difference between expressive and receptive skills, (t = -0.49, p > .05).   

Conclusions: These preliminary data support the idea that investigating both receptive and expressive language skills is critical in order to thoroughly understand the communication abilities of children with ASD.  Additionally, examining receptive deficits may be more informative than exploring expressive deficits when differentiating between children with ASD and those with other types of developmental delays. This is particularly important because receptive language deficits are more difficult to assess. Therefore, it is critical that clinicians utilize measures that reliably elicit all components of language.