Dissymmetry of Sensorimotor and Neurocognitive Functions in Bilingualism

Relevance . The use of two or more languages has a substantial influence on cognitive functions and the structural and functional organization of the brain. Examining the relationship between the dissymmetry of sensorimotor functions and second-language proficiency is relevant to both neuropsychology and educational psychology. It remains unclear how the level of bilingual proficiency is related to the lateral organization profile, interhemispheric interaction, and neurocognitive functions. The debate on the “bilingual advantage” and the concept of the embodied mind provide the theoretical framework for the empirical investigation of these relationships. Intention . To establish the relationships among the dissymmetry of sensorimotor functions, neurocognitive spatial abilities, logical reasoning, and the level of bilingual proficiency, and to describe group variability in lateralized characteristics and cognitive functions depending on second-language proficiency. Materials and methods . The sample comprised 35 international students with different levels of proficiency in Russian as a second, non-native language (L2): ≥ C1 (n = 11), ≤ B2 (n = 7), and ≤ A2 (n = 17). A neuropsychological battery was used, including the Annett test for handedness, the Béla Julesz stereogram for interhemispheric interaction, the Compass test for spatial abilities, and the Tower of Hanoi task for logical reasoning. Spearman’s correlation analysis, hierarchical cluster analysis, and analysis of variance were applied. Results . Most neurocognitive measures showed no significant differences depending on L2 proficiency. The only significant difference was found in the planning time for the Tower of Hanoi task among women with C1 proficiency. Hierarchical analysis showed that the lateral organization profile was determined by both handedness and the level of bilingual proficiency. Conclusion . The neurocognitive profile of a bilingual individual is determined by a set of interrelated factors. The key task is not to identify a single lateralization pattern, but to model the dynamic interaction between hemispheric specializations and the executive control system strengthened by bilingual experience.