Abstract:

Previous studies have found that lifelong bilingual language experience led to bilingual cognitive control advantage. However, a recent study proposes a new viewpoint that bilingual cognitive control depends on fast language context rather than long-term language experience. Thus, whether the cognitive control components are influenced by language switching context is still an open question. In the current study, two experiments were conducted to investigate the immediate influence of language switch on cognitive control’s different components. Experiment 1 examined whether language switching context had immediate influence on cognitive control and whether the influences are existed on various components of cognitive control. Thirty participants joined in the Experiment 1 that contains three parts: pre-test part, language switching part and post-test part. In the pre-test part, all participants were asked to complete a “faces task”, which was used to test three components of cognitive control capacity (i.e., response inhibition, interference suppression and cognitive flexibility). Then, they performed a language switch task, in which they were required to name some Arabic numbers from 1 to 8 in Chinese or English according to the cues. When the cue was a green square (or red), participants named the Arabic numbers in Chinese (or English) when the cue was a red square. Finally, participants took part in the “faces task” again in the post-test part. Results showed that language switching context could influence bilinguals’ different components of cognitive control. Specifically, it can facilitate response inhibition and disturb interference suppression, while cannot affect cognitive flexibility. Therefore, response inhibition, interference suppression, and cognitive flexibility were distinct cognitive control components, which had different neural basis. Experiment 2 was conducted to test two questions. First, we intended to replicate the immediate effect that was observed in Experiment 1. Second, we aimed to explore the causes of the immediate effect. A between-subject design was used in Experiment 2. Ninety-three participants were divided into three groups. Each group performed different language naming tasks. One group named the Arabic numbers in Chinese, while the second group in English. The third group performed language switching task that is the same as Experiment 1. Then, all groups joined in the “faces task.” The results were consistent with Experiment 1, which may suggest that our results are robust. In addition, the results showed that non-proficient Chinese-English bilinguals need more response inhibition because they preferred to use English in language switching. Thus their response inhibition capacity improved by exercises. However, this effect may hinder bilinguals’ interference suppression, while we did not find such effect on cognitive flexibility. Taken together, results from these two experiments suggested that language switching context had immediate influences on non-proficient bilinguals’ cognitive control ability. Specifically, it could facilitate response inhibition and disturb interference suppression, while no such effect was found on cognitive flexibility. Besides, the results showed that response inhibition, interference suppression, and cognitive flexibility had independent mechanisms. Furthermore, the current study illustrated that the bilingual cognitive control advantages were the results of long-term bilingual language use, which revealed the internal mechanisms of the bilingual advantage.

Key words: language switch, language context, components of cognitive control, bilingual advantage