Mattingly (1972)
famously proposed that "reading is parasitic on speech." Mattingly was more or less right. In this chapter we propose a broader view: Reading is parasitic on language.
It is common to distinguish between four domains of spoken language: phonology, grammar, semantics, and pragmatics. For reading it is important to make a distinction between recoding (usually assessed by the accuracy of reading aloud) and comprehension (the adequacy of understanding text, usually assessed by questions about the meaning of a passage). In this chapter we will argue that recoding is parasitic on phonology and that comprehension is parasitic on grammar, semantics, and pragmatics as well as phonology (because phonology is essential for recoding, without which there can be no comprehension, Gough & Tunmer, 1986). So reading, in the sense of reading for meaning, depends on all four domains of oral language. We will develop this idea by considering the different patterns of reading impairment that can be observed in children who have a variety of different forms of language impairment.
Models of Reading Development
To understand a disorder of development depends on having a model of normal development. To understand how different types of language impairment impact on the process of learning to read we need a model of how language processes operate to determine the course of normal reading development. We therefore need a model of reading that is explicitly concerned with learning and how this learning depends upon the integrity of underlying language skills. For this purpose the most useful theoretical framework is the "triangle" model that has guided the development of a variety of connectionist models of reading development (Harm & Seidenberg, 1999;