ABSTRACT
This chapter presents a case study of M.P.'s reading performance with a large number of exception and regular words to document the breakdown in her whole-word knowledge and the consequent reliance on a more stereotyped, rule-based approach to written word pronunciation. It explains what aspect of whole-word specification has been lost for these items; some evidence suggests that M.P.'s functional impairment is localised at the level of phonological retrieval than at the level of orthographic representation for words. Partial failure of the lexical route is apparent when M.P. is asked to read words with an irregular spelling-sound correspondence. In contrast to the accurate performance obtained for regular words, M.P.'s reading of exception words is frequently incorrect, with overwhelming majority of errors dictated by inappropriate but valid application of spelling–sound principles. The nature of the impairment is not entirely clear, but the most reasonable assumption is that for words pronounced via principles of spelling–sound correspondence, the lexical entries are completely lost.
