Abstract
Cluster analysis of test scores on expressive phonology and comprehension of words and sentences in 7–9-year-old children with preschool diagnosis of Autistic Disorder yielded 4 clusters. Cluster 1 (N = 11): phonology and comprehension both low; Cluster 2 (N = 4): phonology low, near average comprehension; Cluster 3 (N = 40): average phonology, comprehension low to low average; Cluster 4 (N = 7): average or better phonology and comprehension. The clusters support two major types of language disorders in autism driven by impaired expressive phonology, each divisible by comprehension ability. The clusters refute a single language disorder in autism and are consonant with earlier-defined clinical subtypes.
Notes
This article was supported in part by NINDS grant # 20489.
A list of abbreviations is presented at the end of the article.
aInadequate verbal and nonverbal pragmatics (conversational use), lack of compensatory gestures, and aberrant prosody distinguish children on the autism spectrum (ASD) from children with developmental language disorders (DLDs/specific language impairments—SLIs). ASD children likely to have atypical features (e.g., echolalia, pronominal reversal, perseveration, repeated questioning, idiosyncratic word choices).
bOromomor deficits (oromotor dyspraxia), that is, impaired voluntary control of the oromotor musculature for nonverbal tasks like swallowing, chewing, moving the tongue to command, and so on. Frequent in dysfluent children with global language disorders or verbal dyspraxia. Not causative but likely to contribute to poor speech (e.g., slurred, dysrhythmic, unintelligible, or even absent). Due to neurologic disorders that do/do not affect language circuitry.