Poster B26, Thursday, August 16, 3:05 – 4:50 pm, Room 2000AB
Neural signature of Cross-Linguistic Influence in L2 Learning
Hiroshi Ishinabe1,2, Hyeonjeong Jeong3,4, Shigeyuki Ikeda3, Takayuki Nozawa5, Kohei Sakaki1, Motoaki Sugiura3,6, Ryuta Kawashima3;1Graduate School of Medicine, Tohoku University, 2Department of Social Care, Higashiosaka Junior College, 3Institute of Development, Aging and Cancer, Tohoku University, 4Graduate School of International Cultural Studies, Tohoku University, 5Research Center for the Earth Inclusive Sensing Empathizing with Silent Voices, Tokyo Institute of Technology, 6International Research Institute of Disaster Science, Tohoku University
INTRODUCTION: It has been suggested that the cross-linguistic similarity between mother tongue (L1) and second language (L2) is an important factor in determining brain activation patterns during L2 processing and determining whether learners acquire L2 successfully or not (Jeong et al., 2007, Kotz, 2009). However, it is difficult to control factors such as L2 proficiency or linguistic features (i.e. syntax) when it comes to designing experiments. Furthermore, it is still unclear whether this effect of cross-linguistic factor influences the initial stage of brain mechanism of L2 grammar learning, and if so, how? In this study, we hypothesized that the neural mechanisms during L2 learning are affected by the cross-linguistic similarity as well as during L2 grammar processing. To test the hypotheses, the present fMRI study investigates brain activation during L2 learning using artificial languages. METHODS: Thirty-Seven Japanese native speakers were recruited (Sixteen females and twenty-one males, mean age: 20.4, SD: 1.2). We created two artificial languages which were named DL (Dissimilar Language) and SL (Similar Language). In DL, word order (Verb-Subject-Object) and morphosyntactic system were NOT similar to the participant’s L1 (Japanese). In SL, word order (Subject-Object-Verb) and morphosyntactic system were similar to the participant’s L1. Both DL and SL were written in Roman letters, and had the same eleven words. The participants were randomly assigned into two groups: the DL learning group and the SL learning group. We controlled individual differences such as IQ, their L2 (i.e. English) proficiency, and foreign language anxiety level. Both groups underwent MRI scans during Grammar-Learning Session (Learning) and Grammar-Test Session (Testing) at three time-points (1st-phase, 2nd-phase, and 3rd-phase) in a day. The fMRI data of Learning and Testing were modeled separately using a General Linear Model. To elucidate the effect of individual learning skill, a correlation analysis was conducted between the gain score of Testing and activation in the observed brain areas. Statistical analyses were performed with SPM12, using a random effects model (corrected to p<0.05 by FWE). RESULTS: Comparison between DL and SL groups during Testing revealed that the DL group recruited greater activation in the left inferior frontal gyrus. In contrast, SL group recruited greater activation in the lingual gyrus. Consistent with previous findings (Jeong et al., 2007), the results of Testing demonstrate the cross-linguistic effect due to linguistic similarity. Furthermore, the correlation analysis revealed that activation patterns in the left IFG and lingual gyrus during the 1st and the 3rd Testing phases were significantly correlated with the gain scores of each participant in the DL and SL groups, respectively. Comparison between the DL and SL groups during Learning showed that the DL group recruited greater activation in the left IFG than the SL group did. In contrast, the SL group recruited the left hippocampus and left caudate. Consistent with the results of Testing, the left IFG plays a crucial role in the cross-linguistic effect due to linguistic distance even during grammar learning. CONCLUSION: Cross-linguistic differences are the major determinant of brain mechanism involved in the initial stage of L2 learning.
Topic Area: Grammar: Syntax