Learning a Second Language in Adulthood Changes Subcortical Neural Encoding.

Area of Science:

• Neuroscience
• Linguistics
• Auditory Neuroscience

Background:

• Second language acquisition (SLA) impacts neuroplasticity, primarily in cortical regions.
• Subcortical neural encoding mechanisms in SLA remain under-explored.
• Investigating subcortical changes offers insights into brain plasticity.

Purpose of the Study:

• To investigate the effects of learning a tonal language (Mandarin Chinese) on subcortical neural encoding in adults.
• To utilize frequency-following response (FFR) to assess auditory processing changes.
• To compare neural encoding across native speakers, second language learners, and non-native speakers of foreign languages.

Main Methods:

• Recruited three groups: native Mandarin speakers (NS), Mandarin learners (L2 learners), and native speakers of other languages (NSFL).
• Measured auditory neural encoding using frequency-following response (FFR).
• Compared FFRs across the three distinct language experience groups.

Main Results:

• Second language learners (L2 learners) exhibited more robust FFRs than the NSFL group.
• FFR robustness in L2 learners was less pronounced than in native speakers (NS).
• A significant difference in subcortical neural encoding was observed between groups.

Conclusions:

• Subcortical auditory neural encoding is trainable in adulthood through second language acquisition.
• Neuroplasticity at the brainstem level can be influenced by learning a new language.
• Tonal language learning may specifically enhance auditory processing capabilities.