Heterogeneity and plasticity in the development of language: a 17‐year follow‐up of children referred early for possible autism

Abstract

Background: Delayed, abnormal language is a common feature of autism and language therapy often a significant component of recommended treatment. However, as with other disorders with a language component, we know surprisingly little about the language trajectories and how varied these might be across different children. Thus, we know little about how and when language problems might resolve, whether there are periods of relative stability or lack of change and what periods might offer more favourable circumstances for intervention. Methods: Expressive and receptive language was measured on six occasions between age 2 and 19 on a cohort of 192 children initially referred for autism. Latent class growth models were fitted to characterize the patterns of heterogeneous development. Results: Latent class growth analysis identified seven classes. Between age 6 and 19, all classes tracked in parallel. Between ages 2 and 6, development was more heterogeneous with considerable variation in relative progress. In all groups, receptive and expressive language developed very largely in tandem. Conclusions: The results confirmed previous analysis of children with specific language impairment where progress beyond age 6 was remarkably uniform. Greater variation was evident before this age with some groups making clearly better or worse progress compared to others. While this developmental heterogeneity may simply be a reflection of variation in preexisting and unchanging biological disposition, it may also reflect, at least in part, greater sensitivity in the early years to environments that are more or less supportive of language development. These findings contribute to the case for the importance of early intervention.

A Comprehensive Examination of Reading Heterogeneity in Students with High Functioning Autism: Distinct Reading Profiles and Their Relation to Autism Symptom Severity

“…The distinction between the two latter profiles may be thought of as categorically distinct areas of a continuum, such as the difference between the terms "below average" and "far below average" that are sometimes used in diagnostic measures. This is consistent with longitudinal evidence from Pickles et al (2014) that oral language impairments in ASD present in parallel patterns of development and proficiency levels after the age of seven. Together these two subtypes comprised about 47% of the sample.…”

“…The differences might be a result of the younger age (i.e., second grade) used in the Catts et al (2003) study. However, language delay and impairment is common in children with ASD (Pickles et al 2014) and it is probable that children with ASD who struggle with reading are more typified by impairments in either language comprehension alone or language comprehension coupled with word reading difficulties. This could explain the lack of a dyslexic profile along with a greater prevalence of children who resembled the language-learning disabilities subgroup in Catts et al (2003).…”

A systematic review and meta-analysis of the prognosis of language outcomes for individuals with autism spectrum disorder

“…The adaptive and structural language trajectories reported in the few studies conducted during adolescence were flatter for children from middle childhood to adolescence with a growing gap between language ability in children with ASD and reference norms (Pickles, Anderson, & Lord, 2014;Sigman & McGovern, 2005). Similar findings were reported in studies of adults (Howlin et al, 2004).…”

Associations between joint attention and language in autism spectrum disorder and typical development: A systematic review and meta‐regression analysis

“…Language variables were considered separately, since there is evidence that receptive and expressive language are at least partially disassociated, especially in children with ASD [Pickes, Anderson, & Lord, 2014;Woynaroski, Yoder, & Watson, 2015]. Meta-regression was used to determine if effect sizes vary according to the moderators 1 of interest (i.e.…”