Identifying a supramodal language network in human brain with individual fingerprint

Area of Science:

• Neuroscience
• Cognitive Science
• Linguistics

Background:

• Understanding the neural basis of language is crucial.
• Previous research often focused on single modalities, limiting insights into a universal language system.
• Investigating modality-independent language processing is key to a comprehensive brain map.

Purpose of the Study:

• To identify brain regions processing human language irrespective of its form (spoken, written, signed).
• To explore individual differences in neural responses to language across modalities.
• To compare novel fingerprinting methods with conventional group-mean analyses.

Main Methods:

• Analysis of cortical responses to spoken, written, and signed sentences in individual subjects.
• Application of a novel brain activity fingerprinting method to identify modality-independent networks.
• Comparison of cross-modal prediction success between bilinguals and monolinguals.

Main Results:

• A left-lateralized language network including the superior temporal gyrus/sulcus (STG/STS), inferior frontal gyrus (IFG), precentral gyrus/sulcus (PCG/PCS), and supplementary motor area (SMA) was identified.
• Distributed activity patterns in these regions predicted responses across spoken, written, and signed modalities in an individual-specific manner.
• Cross-modal prediction was successful for speech-sign bilinguals but failed for monolinguals in sign-involved pairs, unlike conventional group analyses.

Conclusions:

• A core language system exists in the brain, shared across spoken, written, and signed modalities.
• Individual differences in brain activity patterns are valuable for functional brain mapping of language.
• The findings highlight the importance of considering individual variability in neuroscience research.