Current Profiles and Early Predictors of Reading Skills in School-Age Children with Autism Spectrum Disorders
The number of studies exploring reading skills of children with autism spectrum disorders (ASD) has grown in recent years. A lot of this research has focused on the mismatch between stronger word reading (decoding) and weaker reading comprehension observed in some children with ASD, with the term “hyperlexia” sometimes being used to describe an extreme version of this profile. However, other studies have noted a very considerable heterogeneity in reading capacity between children with ASD.
To study reading profiles and early predictors of reading in a cohort of school-age children. At age 2.5 years the cohort underwent an autism assessment following identification in a population-based screening. At age 8 years, we used a subgrouping procedure based on individual children’s scores on standardized tests of word reading and reading comprehension to determine the prevalence of different reading profiles. The identified subgroups were then compared both concurrently and retrospectively on a range of linguistic, cognitive and social skills data.
A total of 53 Swedish speaking school-age children with ASD were followed up using a broad test battery tapping aspects of reading, print knowledge, oral language comprehension, oral language production, nonverbal IQ and severity of autistic presentation. Oral phonological processing was also assessed since this is considered a key correlate of word reading development.
Intake-data at age 2.5y included ADOS, adaptive social and communicative functioning and oral language comprehension and production.
Approximately half of the sample (n = 25) performed generally poor in reading, meaning that they scored below the normal range on both word reading and reading comprehension tests. In contrast, a sizable minority (n =18) were skilled readers performing above cut off. A final subgroup (n = 10) presented with the hyperlexic profile of normal-to-strong word reading, but poor reading comprehension. The generally poor subgroup was found to score poorly on most assessments, as well as showing a more severe autistic presentation than skilled readers. Group differences between skilled and hyperlexic readers were more selective: whereas the subgroups did not differ on autistic severity, phonological processing, print knowledge or nonverbal IQ, the hyperlexic subgroup scored poorly on tests of oral language comprehension.
When intake data were considered, no differences were seen between the subgroups in social skills or autistic severity. Importantly, however, already at this age it was possible to identify oral language comprehension difficulties in the subgroups that five years latter presented as generally poor or hyperlexic readers.
The results of this unique population-based study of children with ASD confirm a high degree of heterogeneity in reading skills in ASD. Yet, the patterns appeared to be predictable and align well with established findings in general reading research: that word reading is backed up by phonological skills, whereas reading comprehension builds on a foundation of language comprehension.