Complex brain network properties in late L2 learners and native speakers.

Area of Science:

• Neuroscience
• Psycholinguistics
• Cognitive Science

Background:

• The neural basis of second language (L2) processing in proficient late bilinguals remains debated.
• Understanding how L2 differs from the first language (L1) in the brain is crucial for cognitive neuroscience.

Purpose of the Study:

• To investigate the neural mechanisms underlying L2 processing in highly proficient late bilinguals.
• To compare brain functional network dynamics in L2 learners and monolinguals during syntactic violation detection.

Main Methods:

• Utilized electroencephalography (EEG) to record brain activity.
• Applied complex brain network analysis to assess time-varying topological properties of functional networks.
• Compared Spanish-English late bilinguals with Spanish monolinguals reading sentences with and without gender mismatch violations.

Main Results:

• Late L2 learners exhibited reduced parallel information transfer and slower signal propagation in brain networks during gender mismatch conditions.
• Spanish monolinguals did not show significant differences between sentence conditions.
• Neural activation patterns differed in late bilinguals when processing L2 morphosyntactic incongruence not present in their L1.

Conclusions:

• Highly proficient late bilinguals recruit distinct neural network configurations for L2 processing, especially when encountering unfamiliar grammatical structures.
• The brain's functional network dynamics adapt differently in bilinguals compared to monolinguals when processing specific L2 grammatical challenges.