Reading aloud and lexical decision in neglect dyslexia patients: a dissociation.

This study investigated the dissociation between reading aloud and lexical decision in six Italian right-brain-damaged patients with left neglect dyslexia. Patients were requested to perform two tasks: (a) reading aloud and lexical decision on monomorphemic words of different frequencies and non-words with different degrees of similarity to real words (Experiment 1); (b) reading aloud and lexical decision on morphologically complex (suffixed) derived words and morphologically complex (suffixed) non-words (Experiment 2). The patients' performance on lexical decision was compared to that of a group of matched control subjects. Patients showed left neglect dyslexia in the reading aloud task, but had a normal level of performance in the lexical decision task. Furthermore, patients were affected by the same morpho-lexical variables that influence lexical decision in normal subjects, suggesting a largely preserved morpho-lexical processing of written letter strings, as assessed by the task of lexical decision. The mechanisms underlying the preservation of lexical decision in patients with left neglect dyslexia are discussed in the light of dual route models of reading.