A Neuroeducational Approach to Defining the Cognitive Profile of Comorbid Math and Reading Disabilities

Abstract

Psychoeducational studies have shown that the comorbidity between reading disability and mathematical disability is relatively high but the neuroanatomical substrates that may underlie this comorbidity have not been reliably identified. We developed a novel neuroeducational approach to bridge the corresponding concepts on learning disabilities in the neuropsychological and psychoeducational fields. First, we assessed the cognitive profiles of individuals with reading, mathematical and both disabilities (comorbid group), using psychoeducational tests also often used in neuropsychological test batteries. Second, we performed a systematic review of current literature on the neuroanatomical substrates of dyslexia and dyscalculia. Third, we mapped the cognitive profiles to the neuroanatomical substrates plausibly shared with dyslexia and dyscalculia. The comorbid group exhibited reading deficits similar to those shown by individuals having reading disability alone, which may be associated with atypical function at the left inferior frontal and left fusiform gyri similar to the mathdisabled group; they also exhibited deficits in quantitative reasoning, which may be associated with a bilateral atypical function of the intraparietal sulci. Further deficits related to verbal working memory and semantic memory were exclusive to the comorbid group. The current approach suggests that impaired phonological, numerical, semantic, and working memory processes may be associated with atypical function of the left angular gyrus in both reading and mathematical disabilities.iii