The effects of task complexity on L2 oral production as mediated by differences in working memory capacity

Abstract

This paper analyzes the effects of increasing task complexity along reasoning demands on L2 oral performance, factoring in individual differences in working memory capacity (WMC) and affective factors. Existing research in manipulation of oral task cognitive demands has until only recently overlooked the role of individual differences. In this experiment, thirty subjects performed both a simple and complex version of a decision-making task (counterbalanced), three different working memory (WM) tests, and an affective variables questionnaire. A novelty of this study is the use of subjective time estimation, together with time on task and affective difficulty, as an autonomous measure of the cognitive load of the task. The three measures display a significant difference in complexity between the two versions of the task. The analysis showed that increased task complexity caused a decrease in fluency and an increase in accuracy with no overall effects of WMC or affective factors. Only attention control displayed a weak negative correlation with lexical complexity and a positive one with structural complexity. Results are discussed in the light of cognition theories, WM models of processing and attention and previous findings in task based research.