The timing of language learning shapes brain structure associated with articulation

Area of Science:

• Neuroscience
• Cognitive Science
• Linguistics

Background:

• Bilingualism impacts brain structure and function.
• Understanding how the brain develops with language acquisition is crucial.

Purpose of the Study:

• Compare brain structure in simultaneous and sequential bilinguals.
• Investigate how the timing and proficiency of second language acquisition affect neural development.

Main Methods:

• Used neuroimaging to compare gray matter density in simultaneous and sequential bilinguals.
• Correlated accent proficiency with brain structure in sequential bilinguals.

Main Results:

• Simultaneous bilinguals showed increased gray matter density in the left putamen, left posterior insula, right dorsolateral prefrontal cortex, and bilateral occipital cortex.
• Sequential bilinguals exhibited increased gray matter density in the bilateral premotor cortex.
• Higher accent proficiency in sequential bilinguals was associated with greater gray matter density in the left putamen and sensorimotor regions.

Conclusions:

• Second language learning enhances specific brain structures.
• The pattern of brain enhancement depends on whether languages are learned simultaneously or sequentially.
• Native-like proficiency in sequential bilingualism is linked to greater structural brain changes in sensorimotor and speech-motor control areas.