Lateralization in Neurosemantics: Are Some Lexical Clusters More Equal Than Others?

In this study, we have implemented neurosemantic analysis to identify brain’s voxel-wise representations of words in Russian spoken narratives and their asymmetries in the brain. 25 subjects listen to five stories, first person narratives of dramatic events, while their brain activation was registered by 3T functional magnetic resonance imaging (fMRI). Seven best subjects in terms of their engagement and objective control of brain reaction were selected for further analysis. Twelve lexical clusters were found, with different semantics – from time-and-space concepts to human actions and mental states. Clusters “experience” and “threat” were ones that on average demonstrated a symmetrical localization. For other clusters, brain localization has a left-sided bias. Our results support the view of non-modular and widely distributed nature of semantic representations, not limited to the activity of structures in the temporal and frontal lobes. These results also demonstrate that the right hemisphere can be involved in representation of mental lexicon. Our findings were broadly consistent with those reported for the English language, which points to the universality of the factors governing brain’s lexical representations.