Concreteness shapes semantic representations in bilingual brains

Abstract

Behavioral studies show that humans process concrete words more similarly across languages than abstract words. This suggests that in bilingual brains, semantic representations may be more similar across languages for concrete concepts than for abstract concepts, but existing neuroimaging evidence is inconclusive. Here, we analyzed functional magnetic resonance imaging (fMRI) data from fluent Chinese-English bilinguals who read several hours of naturalistic narratives in both languages. We used encoding models to estimate voxelwise tuning towards concrete and abstract concepts in each language separately. We then quantified the similarity of cortical semantic representations across languages. First, we find that the cortical organization of concreteness tuning is consistent across languages. Second, semantic representations are similar across languages for both concrete-tuned voxels and abstract-tuned voxels. Third, we find that for abstract concepts, cross-language similarity of semantic representations may be driven by emotionality. Overall, these findings reveal how concreteness affects semantic representations in bilingual brains.