Date of Award

Spring 5-11-2017

Degree Type


Degree Name

PhD Health Sciences


Health and Medical Sciences


Venu Balasubramanian, Ph.D

Committee Member

Genevieve Pinto-Zipp, Ed.D

Committee Member

Nadine Martin, Ph.D


Dual-route model, cognitive neuropsychology, dysgraphia, dyslexia, Arabic orthography, aphasia


Objective: The cognitive neuropsychology is based on the “universality” assumption, which suggest that all normal people have the same cognitive systems regardless of their culture and language (Coltheart, 2001). The aim of the study is to test the universality assumption of the dual-route model (DRM) for spelling and reading in modern Arabic language. The study follow the same architecture of the DRM taking into considerations specific variables that hold certain features of the Arabic script. Methods: The study results were secured by using case series method analysis of each individual participant’s performance. The Case series method offered the ability to look into each individual’s symptoms and error types and also took into account individual variances. The profiles of fifteen adults with left-hemisphere strokes were investigated by analyzing their performance in writing to dictation and reading aloud tasks of words and non-words, and discuss the profiles of acquired dysgraphia and dyslexia in these individuals. Results: The patterns of impairment observed in each patient were discussed based on the dual-route model of spelling and reading aloud. The results yield different types of dysgraphia and dyslexia but no evidence of surface dysgraphia or surface dyslexia. The types of spelling impairments were graphemic buffer dysgraphia (46%), followed by mixed dysgraphia (27%) and lastly phonological dysgraphia (20%). Reading aloud impairment, on the other hand, showed a majority of deep dyslexia (46%), followed by phonological dyslexia (20%), mixed dyslexia (14%), and a much lower incidence of letter-by-letter dyslexia (6%). Conclusion: All of the components hypothesized by DRM were impaired to some degree in each participant. These components are cognitive functions that in Arabic skilled reader, comprise a highly practiced mechanism specialized for spelling and reading aloud. Elements of these components, such as the sub-lexical route may be involved differently and that the relative impact of both routes varies substantially. The evidence from reading and writing disorders in other languages, as reported in this study, contribute to the theoretical understanding of the cognitive models with the focus on the unique orthographic differences that serve as a basis for hypothesizing about breakdowns within a language.