Word Reading in Hyperlexic Children with ASD

Background: Children with Autism Spectrum Disorders (ASD) often present a hyperlexic reading profile involving outstanding word reading. It has been hypothesized that they may be accessing word representations in an unusual manner. However, data on their use of orthographic or phonological pathways is far from conclusive.

Objectives: To assess semantic, orthographic and phonological processes involved in word reading in persons with ASD and hyperlexia.

Methods: A group of English adolescents with ASD and a word reading to text comprehension discrepancy (n = 14) was matched on chronological and word reading ages to a group of typically developing readers (n = 12). Amongst the ASD participants, when verbal IQ to reading discrepancy was also taken into account, it was possible to distinguish two groups. One, labelled true hyperlexics (n = 7), had word reading scores above their verbal IQ, whereas the other, considered poor comprehenders, obtained comprehension scores below their verbal IQ. Participants completed tasks exploring access to lexical representation using orthographic, semantic and phonological pathways, sub-lexical phonological abilities (spoonerisms, non-word reading and non-word repetition), working and short term memory and rapid naming.

Results: True hyperlexics outperformed poor comprehenders and typically developing children on a task involving phonological lexical representation, and poor comprehenders on a task involving orthographic lexical representation. Their performance was not superior on the sub-lexical, memory or rapid naming tasks, and was equivalent to typically developing children on semantic access to word representations.

Conclusions: Children with hyperlexia show a combination of strong phonological and orthographic lexical representations and typical performance on sub-lexical, working memory and rapid naming tasks. Their superior word reading does not stem from unusual access to word reading. We propose that these results are compatible with an profile of expertise in word reading acquired through extended practice.