A Meta-Analytic Review of Cognition and Reading Difficulties: Individual Differences, Moderation, and Language Mediation Mechanisms

Based on 378 studies, 541 independent samples, and over 34,000 participants, the current meta-analysis aimed to explore the associations between cognition and reading difficulties (RD). Results showed that compared with age-matched typically developing (TD) peers, RD showed deficits across processing speed, short-term memory, attention, working memory, inhibition, switching, visuospatial skills, and updating (g = -0.72 to -0.48), with more individual differences in inhibition, processing speed, switching, attention, visuospatial skills, and short-term memory (The natural logarithm of ratio of standard deviations [SDR] = .03-.17). The cognitive deficits among those with RD were more severe with age, with lower reading and intelligence (IQ) scores, and with verbal cognitive tasks. Individual differences in cognitive skills among those with RD were larger with age, with comprehensive/nonverbal IQ identification, and with reading comprehension identification. Comorbidity did not affect the cognitive profile of RD strongly. Meta-analytic structural equation modeling showed phonological processing and language comprehension explained over 70% of the variance between RD and TD across cognitive skills, yet executive function and visuospatial skills contributed uniquely to RD. These findings highlight a domain-specific cognitive path to RD. That is, cognitive deficits may lead to insufficient language development, causing RD indirectly. However, the association between cognitive deficits and RD is not unidirectional or static. Across development, insufficient accumulation of language skills among those with RD also affects cognitive development, especially in the verbal domain. Without high-quality and sustained instruction, such reciprocal associations between cognitive deficits and RD, forming a vicious circle, may be one major reason for persistent reading struggles among individuals with RD. Public Significance Statement Reading difficulties (RD) are related to a comprehensive set of cognitive deficits, yet there are large individual differences among individuals with RD on most cognitive skills. Executive function and visuospatial skills are uniquely related to RD even after controlling for language skills. These findings suggest that a comprehensive cognitive evaluation may provide more accurate information for individualized instruction for individuals with RD: Either addresses and compensates for cognitive deficits or utilizes cognitive strengths within the framework of explicit instruction on phonological processing, language comprehension, and reading.

Automated summary

This study, based on a large amount of data, found that reading difficulties are related to a comprehensive set of cognitive deficits, but there are large individual differences among individuals with RD on most cognitive skills. Executive function and visuospatial skills are uniquely related to RD. A comprehensive cognitive evaluation may provide more accurate information for individualized instruction for individuals with RD.