Working memory capacity in L2 processing

Abstract

In this paper, we review the current state of the second language (L2) processing literature and report data suggesting that this subfield should now turn its attention to working memory capacity as an important factor modulating the possibility of (near)-native-like L2 processing. We first review three major overarching accounts of L2 processing (Clahsen et al. 2006a, Grammatical processing in language learners. Applied Psycholinguistics 27. 3–42; Ullman 2001, The declarative/procedural model of lexicon and grammar. Journal of Psycholinguistic Research 30. 37–69; McDonald 2006, Beyond the critical period: Processing-based explanations for poor grammaticality judgment performance by late second language learners. Journal of Memory and Language 55. 381–401; Hopp 2006, Syntactic features and reanalysis in near-native processing. Second Language Research 22. 369–397, and Hopp 2010, Ultimate attainment in L2 inflection: Performance similarities between non-native and native speakers. Lingua 120. 901–931) and frame their predictions in terms of the qualitative and quantitative differences in processing expected between native speakers and L2 learners. We next review event-related potential (ERP) research on L2 processing and argue that the field’s current understanding of qualitative and quantitative differences in ERPs warrants an additional focus on variables other than L2 proficiency that can also predict individual differences in L2 processing. Recent L2 research (relying on ERPs, self-paced reading, and other online measures) suggests that the most promising such variable is working memory (WM) capacity. We summarize results from our recent L2 WM studies – and report new ERP findings – that point to the possibility of a modulatory effect of WM capacity on the nativelikeness of L2 processing. We conclude that the study of WM capacity is the logical next step for this L2 processing subfield.