The influence of short-term language-switching training on the plasticity of the cognitive control mechanism in bilingual word production.

This study examined the effect of short-term language-switching training on the cognitive control mechanism in bilingual word production. In two experiments, two groups of relatively proficient but unbalanced Chinese-English bilinguals performed a cued picture-naming task, in which they switched between their two languages. On two consecutive days, the participants took part in four sessions. The same procedure was employed on 2 days in Experiment 1, whereas the cue-language mapping was reversed on Day 2 in Experiment 2. In both experiments, picture naming in the dominant language (L1, Chinese) was slower than that in the weaker second language (L2, English) in all sessions. In addition, the reversed language dominance effect was enhanced with training, suggesting that training proactively increases the amount of inhibition of the dominant L1 at the global level. Furthermore, switching costs in the L1 were reduced with training in Experiment 1, but not in Experiment 2. These results indicate that language-switching training improves the efficiency of reactively exerting inhibitory control over the dominant L1 at the local level. However, when a cue matches with different target languages, the effect of training is absent at the local level. These findings reveal the plasticity and complexity of the cognitive control mechanism as a function of bilingual experience, particularly in language switching.