Working Memory Capacity and Learning L2 Structures under Explicit and Implicit Condition: The Effect of Type of Linguistic Structures

Working memory capacity (WMC) is shown to be correlated with explicit learning conditions, but not implicit (Reber, Walkenfeld, & Hernstadt, 1991). However, recent study shows that the relationship is more complicated (Tagarelli, Borges-Mota, &Rebuschat, 2015) and some other factors such as linguistic complexity can mediate the relationship between WMC and learning condition. This study investigated the relationship between WMC and acquisition of two English linguistic structures with varying degree of complexity, namely past simple tense and relative clauses under explicit and implicit learning conditions. Fifty-nine intermediate Persian learners of English took part in this study receiving either explicit or implicit instruction on two grammatical structures defined as easy (simple past tense) and difficult (relatives) at classroom setting. Their ability to use these structures was measured at three times; once before treatment and twice after it through a timed grammaticality judgment task and an elicited oral imitation task. Complex listening span task was used to measure their working memory capacity. The results of the two-way repeated ANOVA revealed that explicit and implicit instruction were significantly effective in development of easy and difficult structures. The results of correlation for working memory capacity and learning condition revealed that there is no significant relationship between WMC and learning under implicit condition. This result hold true for both simple and difficult linguistic structures. However, under explicit condition, differential results were found for different linguistic structures. Whereas no relationship was found for simple linguistic structures, the relationship between WMC and learning difficult linguistic structures under explicit condition was found to be significant.