Reading processes and executive functions: Evidence for their association in middle childhood

While executive functions (EF) are consistently associated with reading performance, the specific cognitive processes involved in this relationship remain insufficiently understood, particularly in transparent orthographies and socioeconomically diverse contexts. Integrating the Direct and Indirect Effects Model of Reading (DIER) with the Dependency Locality Theory (DLT), this study examines whether working memory is associated with syntactic processing efficiency and whether this relationship is consistent with the proposed cognitive demands of text integration during middle childhood. A cross-sectional study was conducted with 212 children (M = 8.95 years) from Cuenca, Ecuador, stratified by socioeconomic status (SES). Reading processes were assessed using the PROLEC-R battery, and EF were measured using the computerized CogniFit battery. Hierarchical regression and bootstrapped mediation analyses indicated that working memory emerged as the strongest unique predictor of reading comprehension (β = .21), even after controlling for SES. Importantly, syntactic processing statistically mediated this relationship (indirect effect = .09). These findings are consistent with the existence of a “syntactic bottleneck,” suggesting that in transparent orthographies, where decoding is largely automated, working memory is associated with comprehension outcomes in a pattern that aligns with a syntactic processing constraint, whereby higher syntactic complexity is linked to greater demands on available cognitive resources. Furthermore, the results are consistent with a ‘double disadvantage’ pattern in low-SES populations, suggesting the potential value of educational approaches that incorporate explicit syntactic instruction, which may be associated with reduced executive processing demands.