WISC‐III Cognitive Profiles in Children with Developmental Dyslexia: Specific Cognitive Disability and Diagnostic Utility

Abstract

This study analyzed the usefulness of Wechsler Intelligence Scale for Children (WISC-III) in identifying specific cognitive impairments that are linked to developmental dyslexia (DD) and the diagnostic utility of the most common profiles in a sample of 100 Portuguese children (50 dyslexic and 50 normal readers) between the ages of 8 and 12. Children with DD exhibited significantly lower scores in the Verbal Comprehension Index (except the Vocabulary subtest), Freedom from Distractibility Index (FDI) and Processing Speed Index subtests, with larger effect sizes than normal readers in Information, Arithmetic and Digit Span. The VerbalPerformance IQs discrepancies, Bannatyne pattern and the presence of FDI, ACID and SCAD profiles (full or partial) in the lowest subtests revealed a low diagnostic utility. However, the receiver operating characteristic (ROC) curve and the optimal cut-off score analyses of the composite ACID, FDI and SCAD profile scores showed moderate accuracy in correctly discriminating dyslexic readers from normal ones. These results suggested that in the context of a comprehensive assessment, the WISC-III provides some useful information about the presence of specific cognitive disabilities in DD.Keyword: Developmental dyslexia, WISC-III, cognitive profiles, children. Page 2Practitioner Points:• Children with DD revealed significant deficits in the WISC-III subtests that rely on verbal abilities, processing speed and working memory.• The composite ACID, FDI and SCAD profile scores showed moderate accuracy in correctly discriminating dyslexics from normal readers.• WISC-III may provide some useful information about the presence of specific cognitive disabilities in DD. IntroductionDevelopmental dyslexia (DD) is one of the most common learning disabilities (LD), affecting approximately 5% of school-age children (Ramus, 2003) and leading to substantially lower reading performance than expected according to the child's chronological age, intelligence and school grade (American Psychiatric Association, 2000). DD can be conceptualized as a specific LD that is neurobiological in origin and is characterized by difficulties with accurate and/or fluent word recognition as well as poor spelling and decoding abilities (International Dyslexia Association, 2002; Lyon, Shaywitz, & Shaywitz, 2003).Deficits in the phonological domain have consistently been found to be the primary cause of this disorder (see for a review: Fletcher, 2009;Ramus, 2003;Snowling, 2000;Vellutino, Fletcher, Snowling, & Scanlon, 2004), although other cognitive deficits, such as in working memory (Berninger, Raskind, Richards, Abbott, & Stock, 2008;Swanson, 1999Swanson, , 2011, executive functions (Altemeier, Abbott, & Berninger, 2008; Brosnan et al., 2002;Helland & Asbjørnsen, 2000; Reiter, Tucha, & Lange, 2005), processing speed (Shanahan et al., 2006;Thomson, 2003;Willcutt, Pennington, Olson, Chhabildas, & Hulslander, 2005) may play an important role in diagnosis because IQ has to be at least normal and there has to be a signifi...

The Relationship Between Executive Functions with Reading Difficulties in Children with Specific Learning Disorder

“…The results of this study are also inconsistent with the results of Moura O, Simoes MR, and Pereira M's studies, which were on the planning from executive function (25). In their study, there was no significant difference in planning between groups after comparing executive functions between children with learning disorders and normal children.…”

“…In this study, the speed of processing, flexibility, planning, and fluidity of the word was studied in 50 children with reading disorders and 50 normal children between the ages of 8 and 12 in Portugal. After comparing the 2 groups, significant defects were observed in the processing speed, flexibility and fluidity of the word, while there was no significant difference in planning between the groups (25).…”

Executive Functioning in Children With Developmental Dyslexia

“…Several studies have found that children with DD showed deficits on both WISC-III Processing Speed Index subtests (Moura, Simões, & Pereira, 2014a;Thomson, 2003). Shanahan et al (2006) performed a detailed study that examined the presence of PS deficits in children and adolescents with DD and ADHD using a wide range of PS tasks.…”

Working Memory in Portuguese Children With Developmental Dyslexia

“…For years, neurocognitive researchers have observed that children -4 -with DD performed extremely poorly on subtests corresponding to the current Working Memory Index of the Wechsler Intelligence Scale for Children (WISC) -Fourth Edition (ClercqQuaegebeur et al, 2010;Helland & Asbjornsen, 2004;Moura, Simões, & Pereira, 2013).…”