Özet:
The purpose of the study is to investigate the relationships between processing/storage functions of working memory (WM) and explicit/implicit second language (L2) knowledge as well as the contributions of these variables to L2 reading comprehension. Participants were 84 moderately proficient late adult learners of English. WM capacity was measured through reading span tasks administered in L1 and L2 and an operation span task. An untimed grammaticality judgment test (GJT) and a metalinguistic knowledge test were administered to measure explicit linguistic knowledge in the L2 while a timed GJT and an elicited oral imitation test were used to measure implicit linguistic knowledge. Reading comprehension scores were obtained from a retired paper-based TOEFL. Results suggest that WM’s storage function is language independent and it is not affected by the type of secondary task employed. The findings also suggest that WM's processing function is not task-dependent. Furthermore, results corroborate previous studies arguing against a trade-off between the processing and storage functions of WM. Based on the findings regarding the relationship between linguistic knowledge and WM capacity, it can be argued that the type of knowledge assessed by the so called implicit knowledge tests could actually be automatized explicit linguistic knowledge resulting from large amounts of practice in late adults learners of advanced proficiency in an instructional context. This automatized and primarily explicit L2 linguistic knowledge and WM's processing function are the best predictors of L2 reading comprehension, demonstrating the dominant role of automatized knowledge in efficient L2 reading comprehension for instructed L2 learners.