The Differences in Structure and Function of the Cerebellum Between Cantonese-Mandarin Bilinguals and Mandarin Monolinguals: a Multi-model MRI Study.

The effects of the long-term bilingual experience on structure and function of the cerebellum remain unclear. To explore whether there are differences in cerebellar gray matter structure between Cantonese-Mandarin bilinguals and Mandarin monolinguals and whether these different cerebellar structures have different resting-state functional connectivity (RSFC) with the cerebrum between the two groups, 30 Cantonese-Mandarin bilingual and 30 Mandarin monolingual college students were scanned by the T1-weighted magnetic resonance imaging (MRI) and resting-state functional MRI. Voxel-based morphology (VBM) analysis and RSFC analysis were used to analyze the cerebellar gray matter volume (GMV) and cerebellar-cerebro functional connectivity, respectively. Correlation analysis was performed between GMV/RSFC and the rapid automatized naming (RAN) and cognitive control. Compared to Mandarin monolinguals, Cantonese-Mandarin bilinguals showed larger GMV in bilateral cerebellar inferior posterior lobe (including bilateral VIIIa, VIIIb,IX, and right X, Vermis VIIIb, and Vermis IX) and a significant increase in RSFC coupling of the right inferior cerebellar posterior lobe with orbital part of left inferior frontal gyrus (IFG). In addition, there was a positive correlation between average response time (RT) of Mandarin alphanumeric RAN and RSFC between the right inferior posterior lobe of cerebellum and left IFG of all participants. The long-term Cantonese-Mandarin bilingual experience can increase the GMV of the bilateral cerebellar inferior posterior lobe and the RSFC between the right inferior cerebellar posterior lobe with orbital part of left inferior frontal gyrus (IFG).