Overlapping but Language-Specific Mechanisms in Morphosyntactic Processing in Highly Competent L2 Acquired at School...

Area of Science:

• Neuroscience
• Psycholinguistics
• Cognitive Science

Background:

• Bilingualism research often overlooks morphosyntax processing in early second language learners.
• Understanding the neural basis of morphosyntax in bilinguals is crucial for cognitive science.

Purpose of the Study:

• To investigate event-related fMRI during morphosyntactic processing (person-number phi-features) in Turkish (L1) and Persian (L2) bilinguals.
• To compare neural activation patterns between L1 and L2 in syntax-specific and executive function regions.

Main Methods:

• Employed a whole-brain and region of interest (ROI)-based event-related fMRI approach.
• Utilized an alternating language switching design with grammaticality conditions.
• Analyzed activation intensity in left-lateralized syntax ROIs and bilateral executive function ROIs.

Main Results:

• Found significant overlap in neural networks for L1 and L2 processing, indicating structural similarities.
• Observed stronger activation for morphosyntactic processing in L1 compared to L2 across all ROIs.
• Identified distinct hemispheric roles: left for syntax, right for executive control (language switching).
• Noted right planum temporale activation, suggesting a role in auditory attention.

Conclusions:

• Bilingual morphosyntax processing involves integrated, syntax-sensitive, and executive function-sensitive neural mechanisms.
• Differential involvement of language network nodes highlights the complexity of bilingual language representation.
• Early second language acquisition leads to shared neuroanatomical organization for L1 and L2.