Working memory, L2 proficiency, and task complexity: Independent and interactive effects on L2 written performance

Abstract

This study examined the independent effects of working memory (WM) and the interactive effects of WM/L2 proficiency and WM/task complexity on L2 written performance. The study followed a within–between-participant factorial design, with two levels of task complexity as the within-participant variable and L2 proficiency and WM as between-participants variables. The outcome measure was L2 writing performance as measured by CAF indices. Two groups of undergraduate students from a degree in English studies were invited to complete the simple and complex version of the “Fire-Chief” task. Task complexity was operationalized in terms of reasoning demands, and tasks were counterbalanced to avoid unwanted order effects. Participants also completed the Oxford Placement Test and a working memory test (n-back). Regarding independent effects, results show that WM did not have an effect on L2 writing performance. In contrast, L2 proficiency was the variable most connected to various dimensions of the text produced. As for interactive effects, no significant interaction between WM, proficiency, or task complexity was found. In contrast, L2 proficiency emerged as the sole significant predictor of L2 writing performance at both levels of task complexity.

Second Language Implicit and Explicit Knowledge as Indicator of Language Proficiency and Predictor of Working Memory

“…Furthermore, our findings supported those of Park et al (2020) who found a mediation effect between L2 proficiency and WMC in favor of learners with low proficiency. However, the results contradicted those obtained by Manchón et al (2023) who failed to confirm any interactive or mediating effects between WM and L2 proficiency.…”

“…Such findings established a relationship between WM, L2 explicit knowledge as measured by Quick Oxford Placement test, and L2 implicit knowledge as measured by EIT. Manchón et al (2023) inspected the interaction effects of WM, L2 proficiency and task complexity on L2 written production. WM and L2 proficiency were employed as between-subject variables, while task complexity served as a within-subject variable.…”

The role of cognitive factors in second language writing and writing to learn a second language

“…L2 writers with higher WM capacity might be more effective in these complex linguistic encoding processes as they have larger short-term storage and processing capacity available. Nonetheless, it is important to note that Zalbidea's (2017), Marín's (2021), andManchón et al's (2023, in this issue) studies found no significant link between subordination and noun-phrase complexity and WM abilities. Differences across studies might be due to the different types of WM tests and writing tasks used.…”

“…Based on the Direct and Indirect Effects Model of Writing (Kim & Schatschneider, 2017), and Kim et al's (2021) and Manchón et al's (2023, in this issue) studies, it is also possible that WM effects on L2 writing quality are mediated by L2 vocabulary and grammar knowledge. Peng et al's (2021) study with bilingual children, however, demonstrated that WM was directly as well as indirectly related to L2 writing scores.…”