Foreign language proficiency and working memory capacity

In this study, the hypothesis that working memory capacity interacts with (foreign) language proficiency was tested on multilinguals, who were native (L1) Dutch speakers, were fluent in their second (L2) language, German, and had recently started the acquisition of their third (L3) language, Norwegian. So far, the results of second-language studies on simple and complex working-memory tasks are mixed. In previous second-language studies, however, languages that belong to different linguistic groups were used. The question arises whether the interaction between working memory capacity and language proficiency is language-specific. In our multilingualism study we, therefore, controlled for this. Both simple (digit-span) and complex working-memory tasks (reading-span task and letter-number ordering) were used. The general results show that differences in performance between L1, L2, and L3 can be found on both simple and complex working-memory tasks, supporting the working memory capacity interaction hypothesis.