Abstract: At least two processing routes in the brain are involved in pronouncing written words: a semantic route that derives the pronunciation via meaning, and a phonological route that derives it via spelling-sound correspondences. Simulations involving partial damage to an isolated semantic route (Plaut & Shallice, 1993, Cognitive Neuropsychology) provide a comprehensive account of the rather peculiar combination of symptoms exhibited by patients with deep dyslexia}, including the occurrence of semantic errors (e.g., reading RIVER as ``ocean''), their co-occurrence with visual errors, and influences of imageability or concreteness on correct and error performance. Furthermore, when a version of the model is retrained after damage (Plaut, 1996, Brain and Language), the degree and variability of its recovery and generalization are qualitatively similar to the results of some cognitive rehabilitation studies. The results challenge traditional assumptions about the nature of the mechanisms subserving word reading, and illustrate the value of explicit computational simulations of normal and impaired cognitive processes. They also suggest that connectionist modeling can provide a framework for generating specific hypotheses about strategies for rehabilitation.