Dissociating Word Reading and Lexical Decision in Neglect Dyslexia: A Connectionist Account

Neglect dyslexia is a reading impairment acquired as a consequence of brain injury characterized by failures to read verbal material on the left side of a text or at the beginning of words. Neglect dyslexia patients make many errors when naming isolated words, whereas they perform nearly normally when required to make a lexical decision judgment. This behavior has been interpreted in terms of a dual route model where a preserved lexical route is used to perform the lexical decision task, and an impaired non-lexical phonological route is used for naming. We trained a connectionist model to read single words and then lesioned it in order to simulate neglect dyslexia. We show that the damage to the model contributes to the same naming/lexical decision dissociation in a model with a single route for reading.