Does argument structure complexity affect reading? A case study of an Italian agrammatic patient with deep dyslexia

The argument structure complexity hypothesis (Thompson, 2003) was introduced to account for the verb production pattern of agrammatic patients, who show greater difficulty in producing transitive versus unergative verbs (argument number effect) and in producing unaccusative versus unergative verbs (syntactic movement effect). The present study investigates these two effects in the reading performance of a patient (GR) suffering from deep dyslexia. GR read nouns significantly better than verbs; moreover, her performance was better on unergative than on transitive verbs, whereas the comparison between unergative and unaccusative verbs did not differ significantly. Data support the extension of the argument structure complexity hypothesis to word naming and suggest that the two aspects of argument structure complexity occur at different levels within models of lexical processing.