Impaired Audiovisual Representation of Phonemes in Children with Developmental Language Disorder

Abstract

We examined whether children with developmental language disorder (DLD) differed from their peers with typical development (TD) in the degree to which they encode information about a talker’s mouth shape into long-term phonemic representations. Children watched a talker’s face and listened to rare changes from [i] to [u] or the reverse. In the neutral condition, the talker’s face had a closed mouth throughout. In the audiovisual violation condition, the mouth shape always matched the frequent vowel, even when the rare vowel was played. We hypothesized that in the neutral condition no long-term audiovisual memory traces for speech sounds would be activated. Therefore, the neural response elicited by deviants would reflect only a violation of the observed audiovisual sequence. In contrast, we expected that in the audiovisual violation condition, a long-term memory trace for the speech sound/lip configuration typical for the frequent vowel would be activated. In this condition then, the neural response elicited by rare sound changes would reflect a violation of not only observed audiovisual patterns but also of a long-term memory representation for how a given vowel looks when articulated. Children pressed a response button whenever they saw a talker’s face assume a silly expression. We found that in children with TD, rare auditory changes produced a significant mismatch negativity (MMN) event-related potential (ERP) component over the posterior scalp in the audiovisual violation condition but not in the neutral condition. In children with DLD, no MMN was present in either condition. Rare vowel changes elicited a significant P3 in both groups and conditions, indicating that all children noticed auditory changes. Our results suggest that children with TD, but not children with DLD, incorporate visual information into long-term phonemic representations and detect violations in audiovisual phonemic congruency even when they perform a task that is unrelated to phonemic processing.

Language Skills in Children with Attention Deficit Hyperactivity Disorder and Developmental Language Disorder: A Systematic Review

“…The evaluation of various language domains is an integral part of studying language skills. In our collection of articles, we discovered research concentrated on investigating language abilities in a group identified with DLD [31,35,37,39]. In these articles, there was a great diversity as they focused on different language domains, notably syntax, semantics, and pragmatics.…”

“…In these articles, there was a great diversity as they focused on different language domains, notably syntax, semantics, and pragmatics. For example, Kagnovich and colleagues [37] measured general linguistic aptitude and working memory and they found children with DLD had difficulties integrating visual information into long-term a-phonemic representations. However, it should be noted none of the selected studies addressed the study of phonology separately.…”

“…Thus, without early intervention, difficulties at the pragmatic level are expected to persist into adulthood in people with ADHD. For individuals with DLD, difficulties at the structural level of language are expected to persist into adulthood due to deficits in processing speed and short-term memory [10,37,39]. At the group level, adults with DLD tend to have lower scores on language assessments than normative adults [51].…”

Event‐related potentials evidence for long‐term audiovisual representations of phonemes in adults

“…Data from children with developmental language disorder (DLD, a.k.a. specific language impairment or SLI) and their typically developing age-matched peers were described in an earlier publication from our laboratory (Kaganovich et al, 2021). To be able to compare outcomes in both groups, we made the design child-friendly and used it with both children and adults.…”