The specific patterns of structural morphometry underlying functional plasticity and their relationship with language experience remain unclear. Therefore, the current study examined the influence of bilingual experience on cerebral structural morphometry. It also examined the relationship between structural morphology and age of acquisition (or language proficiency, number of languages).
Methodology:
Participants included 25 early bilinguals (19–29 years, M = 22.52, SD = 3.03), 37 late bilinguals (18~28 years, M = 22.00, SD = 2.25), and 29 monolinguals (18~26 years, M = 20.52, SD = 1.92). Participants completed a language background questionnaire and underwent MRI scan.
Data and analysis:
Demographic differences were analyzed using F-tests. Structural comparisons were conducted using CAT12 combined with non-parametric permutation techniques and Threshold-Free Cluster Enhancement. Pearson correlation analysis was employed to examine the relationship between surface indices and behavioral scores.
Findings:
Results showed that bilingual experience caused adaptive changes in structural morphometry. Early bilinguals showed more adaptive changes in their structural morphometry than late bilinguals. Furthermore, these changes were moderated by the number of languages known and language proficiency.
Originality:
Unlike studies that focus on a single or a few indicators, this study is the first to use a multidimensional approach (four measurement indicators: cortical thickness, fractal dimension, gyration degree, and sulcal depth) in a bilingual context to comprehensively capture the neurostructural adaptive changes triggered by bilingual experience. In addition, combining language proficiency, number of languages mastered, and age of language acquisition, the study explores the dynamic interactions between these language experience and structural changes in the brain.
Significance:
Bilingual experiences provide a unique perspective for studying brain plasticity. Understanding how language learning affects brain structure can shed light on the mechanisms by which the brain adapts to different environments and experiences.
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