Describing (pre)linguistic oral productions in 3- to 5-year-old autistic children: A cluster analysis

Abstract

In many autistic children, speech onset is delayed and expressive language emerges after 3 years of age. We qualitatively and quantitatively describe oral productions of autistic preschoolers, including many non- or minimally speaking, recorded during interactions with a caregiver and with an experimenter. Data clustering on manually coded oral production samples indicates five validated linguistic profiles of oral production in this diverse and inclusive sample ( n = 59) of 3- to 5-year-old autistic children with highly variable expressive language abilities. These profiles are then compared on a series of demographic (age, socioeconomic status) and psychometric (autism severity, nonverbal and verbal IQ) measures, as well as on additional measures of language (expressive vocabulary, phonetic inventories). Two clusters are composed of speaking autistic children, while the three others comprise non- or minimally speaking children with qualitatively different patterns of vocal productions. The five-profile division suggests that traditional binary division of speaking vs nonspeaking children does not do justice to the complexity of early expressive language in autism. Lay abstract For most autistic children, spoken language emergence and development happen after the age of 3. Once they start developing and using spoken language, some eventually manage to reach typical levels of language abilities, while others remain minimally speaking into adulthood. It is therefore difficult to consider young autistic preschoolers as a homogeneous group in terms of spoken language levels. In our study, we breakdown a representative and inclusive group of children on the spectrum aged from 3 to 5 into five subgroups that correspond to different linguistic profiles. To do so, we qualitatively described children’s (pre)verbal productions elicited during interactions with a parent and with an experimenter. We then used a type of statistical analysis called cluster analysis to group together the children that had a similar expressive (pre)linguistic behavior. Using this analysis, we were able to delineate five linguistic profiles with qualitatively different patterns of vocal production. Two of these profiles are composed of speaking children; the three others are composed of non- or minimally speaking children. Our findings show that traditional binary division of speaking versus nonspeaking autistic children is not precise enough to describe the heterogeneity of early spoken language in young autistic children. They also support the use of qualitative descriptions of vocal productions and speech to accurately document children’s level of language, which could, in turn, help design very finely tailored language intervention specific to each child.

Structure and acoustics of the speech of verbal autistic preschoolers

“…The children in the ASD group were pooled from a larger sample (n = 59) of three-to five-year-old autistic children that participated in a broader project on early linguistic development in autism which included many children with minimal spoken language abilities, and which was designed to target a critical window for speech emergence in autism, between three and less than six years of age (Anderson et al, 2007). The autistic children described in this paper were identified as being the most verbal children of the larger sample (Maes et al, 2022) and were selected on the basis that, like TD children, they were administered module 2 of the Autism Diagnostic Observation Schedule (ADOS-2; Lord et al, 2012) and not module 1. The ADOS-2 is a gold-standard semi-structured evaluation for the diagnosis of autism; module 1 requires no or little speech and module 2 requires phrase speech.…”

“…In sum, even those verbal autistic preschoolers who have had little language delays are likely to display an atypical speech delivery in terms of the structure and acoustics of their language. Verbal autistic preschoolers who communicate using phrase speech represent a relatively small proportion of the children on the spectrum (e.g., they represent 17% of the larger sample from which they were pooled for the present study (Maes et al, 2022 see Methods section). Such a linguistic profile is thus not very frequent in autistic preschoolers.…”