Acquired dyslexias and the computational modelling of reading

Two current approaches to the computational modelling of reading are the connectionist triangle model approach (parallel processing; distributed representations; models developed via a connectionist training algorithm such as backpropagation) and the DRC ("dual route cascaded") model (serial processing components permitted; local representations; model architecture specified by the modeller rather than acquired by a learning algorithm). One way of testing such computational models is to lesion the computer programs that instantiate the models and study how well the impaired reading of such damaged models corresponds to the patterns of impaired reading seen in people with acquired dyslexia. This is computational cognitive neuropsychology. It has been used with both types of model in attempts to simulate acquired surface dyslexia and acquired phonological dyslexia. The results of this body of work currently favour the DRC model over connectionist models developed within the triangle model framework.