Lexical Acquisition and Phonological Development in Minimally Verbal Children With Autism Spectrum Disorders.

Area of Science:

• Developmental Psychology
• Linguistics
• Speech-Language Pathology

Background:

• Lexical acquisition and phonological development are key milestones in early language development.
• Understanding these processes in neurotypical (NT) children provides a baseline for comparison.
• Children with autism spectrum disorder (ASD) often exhibit delays in language development, including expressive language.

Purpose of the Study:

• To investigate lexical acquisition and phonological development in minimally verbal children with ASD during the first 50-word stage.
• To determine if children with ASD learn words based on their existing speech sound inventories (in-phonology vs. out-of-phonology).
• To examine the relationship between vocabulary size and phoneme inventory in children with ASD.

Main Methods:

• Study included 20 minimally verbal children with ASD (ages 28-72 months) with 5-50 spoken words.
• Spoken words were collected using the MacArthur-Bates Communicative Development Inventories (CDI).
• Speech sound inventories were derived from child utterances; words were categorized as in-phonology or out-of-phonology based on initial phonemes.

Main Results:

• Children produced significantly more in-phonology words than out-of-phonology words (p < .001).
• A moderate positive correlation was found between the number of spoken words and the number of phonemes in the speech sound inventory (r = .534, p = .019).

Conclusions:

• The relationship between lexical acquisition and phonological development is present in children with ASD in the first 50-word stage.
• Findings suggest that children with ASD utilize their existing phonological system for word learning.
• Clinical implications for enhancing expressive language in children with ASD were discussed.