Exploring the Behavioral and Neural Basis of Reading Assessments on Children of Varying Clinical Populations

Abstract

RAN (Rapid Automatized Naming) and TOWRE-II (Test Of Word Reading Efficiency, Second Version) are tests commonly used in a clinical setting to diagnose patients with reading disorder. However, increasing concern has been raised on the differential performance of children from different clinical populations on the RAN test and the possibility of misdiagnosis. In addition, TOWRE-II, an alternate proxy for testing reading performance, is not well understood in children of different clinical populations. To better understand the relationship between reading assessment scores and clinical background, this study quantifies potential behavioral and neural correlates to RAN and TOWRE-II scores in children of varying clinical populations. First, a possible behavioral role in linking both alphanumeric and non-alphanumeric RAN and TOWRE-II scores with ADHD (Attention Deficit Hyperactivity Disorder), DCD (Developmental Coordination Disorder), and RD (Reading Disorder) was evaluated using parental reports. This revealed that children with ADHD, as compared to other groups, achieved lower RAN scores, but not TOWRE-II scores. Next, the study identifies correlated ROI pairs significantly associated to alphanumeric RAN and non-alphanumeric RAN scores. Interestingly, the ROI (Region of Interest) pairs did not overlap between tests, suggesting core differences between possible neural associations to the different test scores. It was found that in comparison to papers that identified a ‘RAN Network’ in adults (mean age 20.6) (Cummine et al., 2015), there was a greater proportion of regions associated with attention and executive functioning significantly correlated with RAN performance in children in this study (mean age 9.8). Finally, a series of mediation analyses were run to understand whether having ADHD, DCD, or RD would mediate RAN performance. ADHD, DCD, and RD were not found to mediate RAN performance on a neural basis. This was determined by assessing whether the ROI pairs associated with each of the clinical labels overlapped with the ones associated with RAN performance. Instead, it is speculated that differences in ROI pair correlations associated to RAN and TOWRE scores may be due to differences in test presentation, potentially leading to a disadvantage for certain clinical populations. This may have implications in evaluating reading assessment scores for children of different clinical populations.