Neurocognitive Profiling of Children with Specific or Comorbid Reading Disabilities

This study concerns the question whether different reading-related neurocognitiveprofiles can be observed for reading proficiency based groupsof children, who attend the upper levels of Dutch primary education. Besidesdistinguishing between normal-to-good reading children and childrenwith Reading Disabilities (RD), subgroups are discerned for two frequentlyreported comorbidities of RD, i.e., Attention Deficit HyperactivityDisorder (ADHD) and Specific Language Impairment (SLI).

The research of this PhD thesis is organized into two empirical sectionson different branches of reading-related neurocognitive research, whichare elaborated in five studies. The first section focuses on the cognitiveprocesses of phonemic awareness and rapid automatized naming, and thefirst study specifically addresses the question as to how the severity ofRD affects the relative importance of these processes. Additionally, it isinvestigated how this works out for above-average and excellent readers.Involving the same processes, the second and third study focus on the issueof comorbidity with SLI and ADHD. The second section contains thefourth and fifth study which investigate the relatively novel link betweenword reading and two aspects of visual attention, i.e., selective attentionand orienting of attention.

In the general discussion the employed working model of reading is suppliedwith empirically based estimates of the neurocognitive effect sizes.A main conclusion of the present study is that the addition of visual attentionmeasurements to a phonological reading model provides an enhancedunderstanding of the cognitive basis of word reading, and offersinteresting new perspectives on differential-diagnostic procedures andtreatment planning.