the orthographic system and an awareness of those features of linguistic representations to which the orthography appeals: phonemic segments, in the case of alphabetic writing; syllables, in the case of morphosyllabic writing. The synthetic linguistic representation is very incomplete; no practical orthography gives anything like a complete representation of the utterance it transcribes. But such a complete representation would be unnecessary. Because of the redundancy of linguistic representations, the module can accept the incomplete, synthetic representation as an input, and, by rehearsing, produce a semantic representation and a complete linguistic representation as output.
On this view, there are two potential sources of reading difficulty that can be characterized as "phonological." One of them, as we have seen, is the phonological component of the module, and some weakness here must underlie the problems of those poor readers who also have difficulty in primary linguistic processing: speech production, speech perception, and short-term recall. The other source of reading difficulty is not modular but cognitive; the need for the reader to be aware of the units of phonological structure in linguistic representations that the orthography appeals to, in order to decode. Lack of such cognitive phonological awareness is quite a different matter from a weakness internal to the module. The two cannot be entirely unrelated, obviously, for in order for awareness to develop, the language module must presumably have been producing the right natural linguistic representations. But it is not surprising that a strong correlation between performance on cognitive segmental awareness tasks and performance on tasks that stress precognitive phonological capacities should prove difficult to demonstrate.
Support from NIH grant HD-01994 to Haskins Laboratories is gratefully acknowledged.
Baddeley A. D. ( 1979). "Working memory and reading". In P. A. Kolers, M. E. Wrolstad, & H. /> Bouma (Eds.), The proceedings of the conference on the processing of visible language ( I, 355- 370). New York: Plenum Press.
Baddeley A. D. ( 1986). Working memory. Oxford: Clarendon Press.
Baddeley A. D., & Hitch G. J. ( 1974). "Working memory". In G. Bower (Ed.), Recent advances in learning and motivation, VIII (pp. 47-90). New York: Academic Press.
Brady S., Shankweiler D., & Mann V. ( 1983). "Speech perception and memory coding in relation to reading ability". Journal of Experimental Child Psychology, 35, 345-367.