Receptive and Expressive Language Skills and Non-Verbal Cognitive Abilities Among Preschool-Aged Autistic Children with Delayed Expressive Language

Background: A DSM-5 autism spectrum diagnosis requires specifying the co-occurrence of language impairment. Considering the gap between receptive and expressive language skills, the APA recommends a separate assessment of these subdomains (APA, 2013). Contrary to typically developing (TD) children, receptive language is usually lower than expressive language in autistic children (Maljaars et al., 2012). Nevertheless, it is sometimes anecdotally reported that some school-aged autistic children demonstrate relatively good receptive skills, despite their low expressive skills (Kasari et al., 2013). Little is known however about receptive versus expressive language skills at preschool age in autistic children. Furthermore, as non-verbal cognitive abilities are a well-documented predictor of language outcomes (Luyster et al., 2008; Thurm et al., 2007), documenting both expressive and receptive language in relation to other important developmental domains such as non-verbal cognitive skills could lead to a better understanding of language development in autism.

Objectives: 1-To compare the differences between expressive and receptive language in preschool-aged autistic and TD children. 2-To compare differences between expressive and receptive language between autistic children with and without delayed expressive language. 3-To compare preschool-aged autistic children with and without delayed expressive language on non-verbal cognitive abilities.

Methods: 53 autistic and 38 TD preschoolers aged from 31 to 78 months (autistic children: M=51.70, SD=12.26; TD children: M=48.73, SD=11.5; p=.25) were assessed with the Vineland Adaptive Behavior Scales (VABS). Autistic children were classified in the delayed expressive language group (DL) (n=27) if their VABS expressive language score was below the second percentile and in the non-delayed expressive language group (NDL) (n=26) if their score was in the normal range (≥2nd percentile). DL and NDL autistic groups were matched on age (p<.89). A subgroup of 29 autistic children (DL: n=12; NDL: n=17), matched on age (p=.05), completed the Raven’s Color Progressive Matrices (Board form) (RCPM).

Results:  A significant interaction was found between group and expressive/receptive language (p<.05). Autistic children had a significantly higher level of receptive language compared to their level of expressive language on the VABS (p<.001) while no difference was found between the two subscales in the TD group (p=.23). Furthermore, when comparing DL and NDL autistic children, only a main effect of type of language was found (p<.001), thus indicating that receptive language was higher than expressive language in both DL and NDL groups. Finally, DL and NDL groups did not differ on RCPM scores (p=.58).

Conclusions:  Whereas TD preschoolers exhibited similar receptive and expressive language skills, autistic preschoolers were characterized by significantly higher receptive than expressive skills. Indeed, language comprehension seems to outdo language production in autistic preschoolers, regardless of their level of expressive language. Furthermore, despite their greater delay in expressive language, DL children performed as well as NDL children on the RCPM, a non-verbal measure of fluid reasoning. These results suggest that each developmental domain has to be documented separately in autistic preschoolers to have a good representation of their skills.