Poster C55, Friday, August 17, 10:30 am – 12:15 pm, Room 2000AB
Bilingual switching experience improves executive control: A follow-up fMRI study
Cong Liu1, Lu Jiao2, Yuan Chen1, Ruiming Wang1;1South China Normal University, 2Beijing Normal University
Some researches deemed that the bilingual advantage in executive control does exist, but others did not. With regard to this debated topic, previous studies mainly used cross-sectional method, which can only examine whether the bilingual cognitive control advantage is correlated with language switching or not, but cannot reveal the causal relationship between them. To address this problem, recent studies began to use longitudinal studies to investigate the effect of bilingual experience on cognitive control and its neural basis. However, the majority of existed longitudinal studies were conducted by short training under laboratory environment, which lack ecological validity. Therefore, it is worth further studying that how bilingual experience under natural situation in daily life shapes individuals’ domain-general executive control network. In this study, we explored how bilingual experience under natural learning environment shapes executive control networks by a follow-up fMRI study. 25 college freshmen from South China Normal University were recruited to complete fMRI scanning twice: the first time is when they just entered college (i.e., pre-test) and the second time is one-year later (i.e., post-test). During one-year academic learning, the college freshmen will have massed learning experience of foreign language, which make them own abundant bilingual switching experience. They were asked to complete color-shape switching task and modified Flanker task in both scanning. The color-shape switching task is used to measure cognitive switching, and the modified Flanker task is used to measure response suppression and interference inhibition. Behaviorally, the results of self-rating language proficiency and Oxford Placement Test indicated that the participants’ language proficiency are significantly improved in the post-test as compared to the pre-test. More importantly, compared with the pre-test, the switching costs for cognitive switching ability was smaller in the post-test, but no behavioral difference for interference inhibition and response suppression. However, the fMRI results showed decreased activation in anterior cingulate cortex (ACC) and left inferior frontal gyrus (LIFG) for cognitive switching, and decreased activation in bilateral inferior frontal lobule and subcortical regions for interference inhibition in the post-test, relative to the pre-test. By contrast, there was no difference in brain activation for response suppression between the two tests. Overall, these findings suggested bilingual switching experience in natural environment could improve executive control, but this improvement was only limited in certain components of executive control. Our study provided new experimental evidence for bilingual advantage, and offered further insights into the neuroplasticity of human brain.
Topic Area: Multilingualism