The left periphery in neglect dyslexia

Background: Neglect dyslexia (ND) is a reading disorder that impairs the left visual field. The Left periphery (LP) is the highest layer of the extended syntactic structure, and it represents the interface between communicative intention and syntactic realization. Topic and Focus are the two central projections of the LP. Sentences involving either Topic or Focus display marked structures in which a constituent, extracted from its original position, is fronted. Aims: The aim of the present study is to test whether sentences containing Topic or Focus display a facilitation effect with respect to canonical word order (SVO) sentences in the reading performance of individuals with neglect dyslexia. Methods & Procedures: Nine participants with neglect dyslexia were tested in a reading task. Participants were asked to read aloud a list of 103 sentences, classified into Condition 1 (experimental condition) and Condition 2 (control condition) based on their syntactic structure. Both substitutions and omissions of letters, syllables, and words were considered as errors. Data were analysed using generalized linear mixed model (GLMM)with accuracy as the dependent variable, condition as independent variable and subjects and sentences as random intercepts. Outcomes & Results: Results showed that sentences containing Topic and Focus were read with significantly less impairment than control sentences (t (100) = -2.06, p = 0.041). Conclusions: Our findings are consistent with previous studies on the effects of syntax in ND as they demonstrate that sentence structure has a crucial influence on driving attention in individuals with ND.