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

Researchers used brain scans to study how autistic children process and repeat made-up words (like 'blonk'). Autistic children found this task harder than typical children and showed different brain activity patterns, particularly in areas controlling speech production. These brain differences were specific to autism and weren't seen in children with reading difficulties who also struggled with the same task.

This neuroimaging study examined brain activity during nonword repetition tasks in autistic children compared to neurotypical children and those with reading disabilities. Autistic children showed poorer performance on nonword repetition and demonstrated reduced activation in the supplementary motor area when phonological working memory demands increased. Brain pattern analysis revealed less accurate classification of speech production processes in autistic children compared to neurotypical peers. Importantly, these specific speech production network differences were not observed in children with reading disabilities who had similar behavioral difficulties, suggesting autism-specific neural mechanisms underlying phonological working memory challenges.

Findings suggest speech-language interventions for autistic children may benefit from targeting speech motor planning and production processes specifically. Neural differences may help explain why standard phonological interventions may need autism-specific modifications to address underlying motor speech network atypicalities.

Sample size not reported. Study design unclear. Limited to nonword repetition tasks which may not capture full range of phonological working memory abilities. Unclear if findings generalize to real-world communication contexts or other speech-language tasks.

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.