Language-switch Of Odd-Even Number Decision In Multilinguals

Multilingual speakers always need to switch between different languages during language processing and language output. In recent years, there are more and more multilingual speakers and the multilinguals'language switching phenomenon becomes increasingly common. The cognitive machinery responsible for this switching ability is very complex. It is widely accepted that such language switching incurs cognitive costs. In recent years, linguists have done a lot of research on multilingualism and their language processing mechanism. The language switching has also become a hot topic for cognitive linguistic study. Previous study has found that there is asymmetrical language switching cost in bilinguals language switching and switching between languages is associated with activity over frontal N2 and parietal (late positive complex) areas of cortex.This study attempts to find out whether asymmetric language switching costs exist in multilingual (Russian-English-Chinese) learners'language switching process and what are the cognitive mechanisms involved in language switching.30 international exchange students who studied Chinese in Dalian University of Technology participated in this experiment. The experiment was based on Jackson et al's odd-even number decision task and was designed on E-prime software. Number words were presented in Russian, English and Chinese, and participants were required to judge whether the words were odd or even as quickly as possible. The behavioral result of the experiment shows that under three languages'switching condition, the mean response time for switch trials is slower than non-switch trials. Switching cost between Russian and English is symmetric, while switching cost between English and Chinese is asymmetric, and switching cost between Russian and Chinese is also asymmetric. The ERP result shows that as early as 50 ms after the stimulus onset, there is switch related activity within the left fronto-central quadrant C3 which represented a detection of the visual stimuli. The early (150ms-300ms) switch-related modulation over left central sensor FC3 in this study reflects semantic processing in these areas. There is a significant increase in the magnitude of switch related negativity compared to non-switch trials in N2 for Russian and Chinese. While the difference of increase in the magnitude of switch related negativity is not significant for English within the time range of 280ms-320ms. Response suppression and response switching share a similar neural substrate. There is a sustained increase in the magnitude of the late positive complex (LPC) for switch trials compared to non-switch trials at sensor Pz. The late positive complex (LPC) at sensor Pz may represent that the subjects are making judgment on the odd/even number and making decision for the task.