Second language experience modulates functional brain network for the native language production in bimodal...

Area of Science:

• Neuroscience
• Cognitive Science
• Psycholinguistics

Background:

• The first language (L1) brain network influences second language (L2) acquisition.
• The impact of L2 learning on the L1 functional brain network remains unclear.
• Bimodal bilinguals offer a unique model for studying language network interactions.

Purpose of the Study:

• To investigate how L2 acquisition alters the functional brain network of L1 processing in bimodal bilinguals.
• To determine if L1 production networks are reorganized to accommodate L2 networks.
• To explore the neural mechanisms underlying L1 production in bimodal bilinguals.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed.
• A picture naming task was used to assess L1 production.
• Comparisons were made between bimodal bilinguals and monolingual speakers.

Main Results:

• Bimodal bilinguals showed greater recruitment of the right supramarginal gyrus (RSMG), right temporal gyrus (RSTG), and right superior occipital gyrus (RSOG) during L1 production compared to monolinguals.
• These regions were associated with automatic L2 activation (RSOG) or cognitive coordination (RSMG, RSTG) between languages during L1 tasks.
• Enhanced functional connectivity was observed between L1/L2-specific regions in bimodal bilinguals during L1 production.

Conclusions:

• L1 production in bimodal bilinguals involves significant L1-L2 interaction.
• Second language acquisition demonstrably changes the functional brain network of the first language.
• The findings support a dynamic and interactive model of bilingual language processing.