Poster C62, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Multivariate analyses reveals distributed and overlapping neural representations of bilinguals’ first and second language
Emily S. Nichols1, Marc F. Joanisse1, Gao Yue2, Liu Li2; 1The University of Western Ontario, 2Beijing Normal University
Currently it is thought that bilingual speakers coactivate their two languages during speech, and that they maintain similar, overlapping lexical representations for both. Despite L1 and L2 sharing a network of structures, bilinguals are still able to function in one language without much intrusion of the other, indicating that there is some degree of distinction of the two languages in the brain. The present study examined whether brain areas that are involved in both L1 and L2 word recognition are reliably representing each language differently. Twenty-six English-Mandarin bilingual adults performed a lexico-semantic recognition task in both languages. We then used Representational Similarity Analysis to examine which brain regions reliably showed different patterns of activity for each language. A split-half correlation technique was used to identify regions in which activity patterns correlated more within-language than between-language. The left medial temporal gyrus and the right cuneus showed separate representations for both English and Mandarin, while the left superior temporal gyrus and the left inferior frontal gyrus represented Mandarin more consistently than English. Interestingly, none of these areas showed differences in level of activation between L1 and L2 in a univariate contrast. The present results show a distinction of language-specific vs. domain-general processing in word recognition, and provide a possible mechanism for how bilinguals maintain each language within an integrated lexicon.
Topic Area: LANGUAGE: Lexicon