Altered engagement of the speech motor network is associated with reduced phonological working memory in autism.

Nonword repetition, a common clinical measure of phonological working memory, involves component processes of speech perception, working memory, and speech production. Autistic children often show behavioral challenges in nonword repetition, as do many individuals with communication disorders. It is unknown which subprocesses of phonological working memory are vulnerable in autistic individuals, and whether the same brain processes underlie the transdiagnostic difficulty with nonword repetition. We used functional magnetic resonance imaging (fMRI) to investigate the brain bases for nonword repetition challenges in autism. We compared activation during nonword repetition in functional brain networks subserving speech perception, working memory, and speech production between neurotypical and autistic children. Autistic children performed worse than neurotypical children on nonword repetition and had reduced activation in response to increasing phonological working memory load in the supplementary motor area. Multivoxel pattern analysis within the speech production network classified shorter vs longer nonword-repetition trials less accurately for autistic than neurotypical children. These speech production motor-specific differences were not observed in a group of children with reading disability who had similarly reduced nonword repetition behavior. These findings suggest that atypical function in speech production brain regions may contribute to nonword repetition difficulties in autism.

Conventions for unconventional language: Revisiting a framework for spoken language features in autism.

Background and aims: Autism has long been characterized by a range of spoken language features, including, for instance: the tendency to repeat words and phrases, the use of invented words, and "pedantic" language. These observations have been the source of considerable disagreement in both the theoretical and applied realms. Despite persistent professional interest in these language features, there has been little consensus around terminology, definitions and developmental/clinical interpretation. Main contribution: This review paper updates and expands an existing framework for unconventional language in autism to include a broader range of non-generative (echolalia and self-repetition) and generative (idiosyncratic phrases, neologisms and pedantic language) features often observed in the language of individuals on the autism spectrum. For each aspect of the framework, we review the various definitions and measurement approaches, and we provide a summary of individual and contextual correlates. We also propose some transitional language features that may bridge non-generative and generative domains (e.g., mitigated echolalia and gestalt language). Conclusions: This updated framework offers a unified taxonomy and nomenclature that can facilitate further investigation and interpretation of unconventional language in autism. Implications: There are important implications of this work for our understanding of the complex interplay between autism and language development. Equally important are the clinical ramifications that will guide evidence-based practice in assessment and intervention for individuals on the autism spectrum.

Word imageability is associated with expressive vocabulary in children with autism spectrum disorder.

Background & aims: Throughout typical development, children prioritize different perceptual, social, and linguistic cues to learn words. The earliest acquired words are often those that are perceptually salient and highly imageable. Imageability, the ease in which a word evokes a mental image, is a strong predictor for word age of acquisition in typically developing (TD) children, independent of other lexicosemantic features such as word frequency. However, little is known about the effects of imageability in children with autism spectrum disorder (ASD), who tend to have differences in linguistic processing and delayed language acquisition compared to their TD peers. This study explores the extent to which imageability and word frequency are associated with early noun and verb acquisition in children with ASD. Methods: Secondary analyses were conducted on previously collected data of 156 children (78 TD, 78 ASD) matched on sex and parent-reported language level. Total expressive vocabulary, as measured by the MacArthur Bates Communicative Development Inventory (MB-CDI), included 123 words (78 nouns, 45 verbs) that overlapped with previously published imageability ratings and word input frequencies. A two-step hierarchical linear regression was used to examine the relationship between word input frequency, imageability, and total expressive vocabulary. An F-test was then used to assess the unique contribution of imageability on total expressive vocabulary when controlling for word input frequency. Results: In both the TD and ASD groups, imageability uniquely explained a portion of the variance in total expressive vocabulary size, independent of word input frequency. Notably, imageability was significantly associated with noun vocabulary and verb vocabulary size alone, with imageability explaining a greater portion of the variance in total nouns produced than in total verbs produced. Conclusions: Imageability was identified as a significant lexicosemantic feature for describing expressive vocabulary size in children with ASD. Consistent with literature on TD children, children with ASD who have small vocabularies primarily produce words that are highly imageable. Children who are more proficient word learners with larger vocabularies produce words that are less imageable, indicating a potential shift away from reliance on perceptual-based language processing. This was consistent across both noun and verb vocabularies. Implications: Our findings contribute to a growing body of literature describing early word learning in children with ASD and provide a basis for exploring the use of multisensory language learning strategies.

Case assignment in English-speaking children: a paired priming paradigm.

This study employed a paired priming paradigm to ask whether input features influence a child's propensity to use non-nominative versus nominative case in subject position, and to use non-nominative forms even when verbs are marked for agreement. Thirty English-speaking children (ages 2;6 to 3;7) heard sentences with pronouns that had non-contrasting case forms (e.g. Dad hugs it and it hugs Tigger) and it was hypothesized that these forms would lead to more errors (e.g. Him hugs Barney) in an elicited phrase more often than if the children heard contrasting case forms (e.g. Dad hugs us and we hug the doggie). Tense/agreement features were also examined in children's elicited productions. The findings were consistent with predictions, and supported the input ambiguity hypothesis of Pelham (2011). Implications for current accounts of the optional infinitive stage are discussed.