The dyslexia spectrum: Continuities between reading, speech, and language impairments
Snowling MJ., Hayiou-Thomas ME.
proposed that 2 dimensions of language are required to conceptualize the relationship between dyslexia and specific language impairment: phonological skills and wider language skills beyond phonology (grammatical, semantic, and pragmatic skills). In this article, we discuss the commonalities between reading and language disorders within the context of a model of reading development that posits phonological skills are a critical foundation for learning to read. Children with dyslexia and specific language impairment typically share a continuity of risk for decoding deficits in reading that can be traced to phonological problems, whereas children who have wider language problems are at risk of reading comprehension deficits. We review evidence that there are both genetic and environmental influences on the language skills that contribute to literacy development before turning to consider implications for the assessment, diagnosis, and treatment of reading disorders. © 2006 Lippincott Williams and Wilkins, Inc.