AoA-L2 and Usage-L2 modulate the functional neuroplasticity of the subcortex

Area of Science:

• Neuroscience
• Cognitive Science
• Psycholinguistics

Background:

• Previous research indicates structural brain differences between monolinguals and bilinguals.
• The impact of diverse bilingual experiences on subcortical functional neuroplasticity remains largely unexplored.

Purpose of the Study:

• To investigate how age of second language acquisition (AoA-L2) and second language usage (Usage-L2) influence subcortico-cortical and intra-subcortical functional connectivity (FC) in bilingual individuals.
• To explore the relationship between specific bilingual experiences and functional connectivity patterns within subcortical brain regions.

Main Methods:

• Utilized resting-state functional magnetic resonance imaging (fMRI) data from bilingual participants.
• Employed multiple regression analysis to correlate brain measurements with bilingual experience variables (AoA-L2 and Usage-L2).
• Focused analysis on functional connectivity within and between subcortical structures.

Main Results:

• Higher AoA-L2 correlated with reduced subcortical FC in regions including the anterior thalamus, basal ganglia, and hippocampus.
• Increased Usage-L2 at home was associated with decreased FC in the amygdala, globus pallidus, hippocampus, and nucleus accumbens.
• Conversely, higher Usage-L2 in social settings showed a positive association with the FC of these subcortical regions.

Conclusions:

• Bilingual experiences significantly modulate the functional neuroplasticity of subcortical brain structures.
• The specific nature of bilingualism, including age of acquisition and context of use, differentially impacts subcortical functional connectivity.