A-048 Semantic, Not Phonetic, Working Memory Performance Predicts Variation in Reading Comprehension in a Mixed Sample

Abstract

Abstract Objective Reading comprehension (RC) is the result of a combination of interrelated abilities including decoding, linguistic processing, and higher-order cognitive functions such as working memory (WM). Problems with RC are associated with deficits in verbal WM, especially on tasks involving semantic processing. Hence, this study’s aim was to determine which is the better predictor of RC when controlling for basic reading ability: semantic or phonetic WM. Semantic WM was hypothesized to be the better predictor. Methods Participants included 258 children (aged 8-13 years) with ADHD, reading disability (RD), or comorbid ADHD/RD, and typically developing controls (53.6% Male, 87.8% Caucasian). Participants completed a neuropsychological battery as part of a larger, grant-funded study (R03HD048752, R15HD065627), including the WJ-III Letter-Word Identification and Passage Comprehension subtests that were utilized to assess basic reading and RC, respectively. Participants also completed the Rhyming Words and Semantic Association subtests of the Swanson-Cognitive Processing Test, which measure phonetic WM and semantic WM, respectively. Results Hierarchical linear regression analyses revealed that worse performance on the semantic WM task was associated with poorer RC (Beta = 0.15; p < 0.001) above and beyond basic reading (R2 change = 0.02, p < .001). Phonetic WM was not related to RC when decoding was controlled despite the zero-order correlation being significant (p < .001), showing much of phonetic WM’s relationship to RC may be due to basic reading requiring this skill. Conclusion Findings suggest differences in RC may be related to semantic WM functioning in children with and without RD, but not phonetic WM, when basic reading is controlled. Replication with a longitudinal design is warranted.