Lexical and Morphosyntactic Profiles of Autistic Youth With Minimal or Low Spoken Language Skills

Autistic youth who are minimally or low verbal are underrepresented in research leaving little to no evidence base for supporting them and their families. To date, few studies have examined the types of words and word combinations these individuals use. The purpose of this study was to take a strengths-based approach to outline descriptive profiles of autistic youth who use few words and elucidate the lexical and morphosyntactic features of their spoken language.

We analyzed language samples from 49 autistic youth ages 6-21 years who used fewer than 200 words. Systematic Analysis of Language Transcripts was used to investigate the relationship between number of different words (NDW) and proportion of nouns and verbs (vs. other word classes), mean length of utterance in morphemes (MLUm), and the frequency of early developing morphosyntactic structures. We used linear regression to quantify the relationship between NDW and lexical and morphosyntactic features.

Proportion of nouns and verbs produced did not increase significantly in those with higher NDW. Conversely, MLUm and the frequency of early developing morphosyntactic structures increased significantly in those with higher NDW.

Youth with higher NDW did not produce more nouns and verbs, suggesting lexical profiles that are not aligned with spoken vocabulary level. Youth with higher NDW had higher MLUm and more early morphosyntactic forms, suggesting that morphosyntactic profiles align with spoken vocabulary level. We discuss the implications for improving clinical services related to spoken language.