Three routes from print to sound: Evidence from a case of acquired dyslexia

Abstract

We report a stroke patient with a reading impairment that is greater for nonwords than for words. She has deficits in the assignment of phonology to sublexical segments, phonological assembly, and visual and verbal STM, but not in the visual recognition of letters and words, nor in graphemic parsing or phonological segmentation. We investigated her ability to read nonwords that are close neighbours of words that she can read well. We found no evidence for reading by analogy. Furthermore, these nonwords are not usually mistaken for the words to which they are close neighbours. Over a seven-year period her reading of words has improved significantly, but her reading of unfamiliar nonwords has not. She can learn to read nonwords on which she is trained, and learning is faster if they are given distinctive meanings. We show that the effect of training is not due to improved sublexical processing, and that nonwords given no distinctive meanings evoke no semantic associations for her. The improved reading of familiar wholes that have no distinctive meanings without improved reading of their parts is evidence for processes that are lexical but not semantic. These findings support theories that propose a semantic route, a sublexical direct route, and a lexical direct route.