Ph.D Thesis

Ph.D StudentBental Barbara
SubjectThe Relationship between Attention, Executive
Functions and Written Language Functions
DepartmentDepartment of Medicine
Supervisor CLINICAL PROFESSOR Emanuel Tirosh


        Co-morbidity of attention deficit hyperactivity disorder (ADHD) and reading disorder (RD) is frequent. The objective of this investigation was to delineate group specific interdependence between attention, executive functions and reading functions among boys with normal oral language abilities. Four groups (19 ADHD, 17 RD, 27 ADHD+RD, and 23 typical controls) were compared on written language functions, executive functions and functions of phonemic awareness and rapid naming. In addition, the effect of Methylphenidate (MPH) was studied in a subgroup of the children with ADHD in a drug/placebo crossover design. The cognitive profiles of the four groups showed the following pattern: While children with ADHD showed unique deficits in some of the executive functions, which were not shared by the pure RD, children with RD were found to present a working memory deficit that was not shared by the pure ADHD. Tests of phonemic awareness did not distinguish between the clinical groups. The co-morbid group showed the basic characteristics of both pure disorders together with a unique deficit in effortful semantic retrieval. Forward stepwise regression pointed to unique associations between executive functions and word reading accuracy in children with ADHD. This finding was strengthened by the effects of treatment with Methylphenidate (MPH) that selectively improved executive functions, rapid naming and word reading accuracy in the co-morbid group. It was  concluded that reading appears to be related to executive functions and attention and to respond favorably to MPH in a subgroup of children with both attention deficit and reading disability.