Interrelationships among L2 linguistic knowledge, working memory functions, and L2 reading

Abstract

The main purpose of the current study is to investigate whether L2 reading comprehension is related to the processing and storage functions of working memory (WM) as well as explicit and implicit sources of knowledge in the L2. Byproducts of this question involve (a) whether the relationship between WM and reading comprehension is attributable to the linguistic nature of the complex span task; (b) whether WM is related to explicit and implicit types of linguistic knowledge in the L2. Participants were 84 late adult learners of English with a B2 level of proficiency. WM capacity was measured through reading span tasks (RST) administered in L1 and L2 and an operation span task (OST). An untimed grammaticality judgment test (GJT) and a metalinguistic knowledge test (MKT) were administered to measure explicit linguistic knowledge in the L2 while a timed GJT and an elicited oral imitation test (EOI) were used to measure implicit linguistic knowledge. Reading comprehension scores were obtained from a retired paper-based TOEFL. A principal component analysis (PCA) on the independent variables revealed a three-component model where processing and storage scores obtained from span tasks loaded on separate components reflecting a distinction between processing and storage functions of WM whereas explicit and implicit L2 knowledge measures loaded together on a single component. A regression analysis performed with factor scores from the PCA as independent variables and L2 reading comprehension scores as the dependent variable revealed significant contributions of WM’s processing function and L2 linguistic knowledge to reading comprehension in the L2. This suggests that the variance shared by WM capacity and L2 reading comprehension is not due to the linguistic nature of the span task but to the general processing efficiency of verbal WM capacity.