The Critical Role of Oral Language Deficits in Reading Disorders: Reflection on Snowling and Hulme
February 22, 2021
Catts, H. W. (2021). Commentary: The critical role of oral language deficits in reading disorders: reflections on Snowling and Hulme (2021). Journal of Child Psychology and Psychiatry, 62(5), 654-656.
Learning to read is a primary goal of early education, and considerable instructional time is focused on it. Most children respond well to this instruction and soon become accurate and fluent readers. But a small percentage of children find learning to read a significant challenge and often struggle educationally and psychologically as a result. In an earlier review, Snowling and Hulme (2012) argued that weaknesses in oral language development play a causal role in reading disorders such as dyslexia and reading comprehension impairment. They further proposed that these impairments should be recognized as distinct disorders within the DSM-5 classification system. In the current review, Snowling and Hulme (this issue) consider how risk factors at the biological, cognitive, and environmental levels combine to cause reading disorders. Again, they focus particular attention on oral language development and its critical role in reading success/failure.
The authors introduce the Simple View of Reading (Gough & Tunmer, 1986) as a framework to distinguish between different types of reading disorders. This model proposes that reading comprehension is the product of word recognition (or decoding) and language comprehension. Simply stated, reading involves decoding printed words into language and using comprehension processes to make sense of this language. Over the last 30 years, hundreds of studies have used this framework to guide or interpret findings related to reading development and disorders. This work has shown that across a wide range of languages, measures of word recognition and language comprehension account for much of the variance in reading comprehension. As Snowling and Hulme highlight, poor readers can be divided into subgroups on the basis of this model. Children with dyslexia have deficits in word recognition but not language comprehension, whereas those with a reading comprehension impairment (also known as poor comprehenders) show the opposite pattern, that is, adequate word recognition but poor language comprehension. Other poor readers can have deficits in both areas. We have also used the Simple View in our work to characterize poor readers (Catts, Hogan, & Fey, 2003). This work has shown that word recognition and language comprehension abilities are dimensional in nature, and while poor readers can be divided along these dimensions, they are spread throughout this two-dimensional space with no clear lines of demarcation between subgroups, a finding shared by Snowling and Hulme. Such dimensional strengths and weaknesses need to be kept in mind especially since this model has begun to find its way into clinics and schools and is being used to characterize poor readers and define practice for them.