Exploring the learning potential of multimodal input-based tasks: The effects of captioning, textual enhancement and working memory on grammatical development

In the field of second language acquisition (SLA), there is a general consensus that attention is necessary for second language (L2) development. Therefore, SLA researchers have shown considerable interest in exploring ways to draw learners' attention to L2 constructions. Of various attention-getting techniques, textual enhancement has attracted much interest from researchers, given its presumed capacity to direct attention to the target linguistic constructions implicitly during meaning-based written comprehension activities. So far, however, few studies have examined the pedagogical potential of textual enhancement when it is included in captions, that is, in the context of multimodal activities combining aural, textual and visual input. This study aims to fill this gap by assessing the potential of typographically enhanced captions to draw learners’ attention to L2 constructions and assist in L2 grammatical development. The study also explored whether these relationships were influenced by individual differences in the phonological short-term memory, visuospatial short-term memory and executive control functions of working memory. The present thesis reports on two empirical studies. Study 1 examined the extent to which increased salience of target linguistic constructions achieved through textual enhancement affected learners’ allocation of attention and development in the use of L2 grammatical knowledge. Study 2 additionally investigated whether individual differences in working memory had mediated the effects of textual enhancement in captions on the allocation of attentional resources and development in L2 grammatical knowledge. In both studies, the participants were Korean learners of English. Attention allocation was measured by eye-tracking methodology and multiple measures were employed to assess L2 development and the functions of working memory. Overall, the results indicated that textual enhancement succeeded in directing learners’ attention to target linguistic constructions and promoting learning gains. However, only marginal effects were observed for working memory in the allocation of attentional resources and developing L2 grammatical knowledge