Why Language Processing Recruits Modality Specific Brain Regions: It Is Not About Understanding Words, but About...

Area of Science:

• Neuroscience
• Cognitive Science
• Linguistics

Background:

• Debate on whether language comprehension necessitates modality-specific brain regions (perception/action).
• Brain imaging shows recruitment of these regions, but lesions don't erase word knowledge, questioning their essential role.
• The precise function of these recruited structures in language processing remains unclear.

Purpose of the Study:

• To re-examine the role of modality-specific brain regions in language processing from a novel perspective.
• To propose that these regions elaborate internal forward models (emulators) for accessing associative memories.
• To present a model where a linguistic system uses emulators and other systems for complementary information.

Main Methods:

• Theoretical examination of existing findings on modality-specific brain region recruitment.
• Postulation of the 'emulator' hypothesis for accessing associative memories.
• Development of a model integrating emulators within a broader linguistic system.

Main Results:

• Modality-specific brain regions are proposed to function as 'emulators' (internal forward models) in motor control.
• During language processing, emulators facilitate access to associative memories and context.
• Recruitment of these regions depends on linguistic context, not the word itself.

Conclusions:

• Modality-specific systems aid language processing by modeling depicted situations via memorized context, not direct word understanding.
• Emulators are one of several information sources exploited by a rule-based linguistic system.
• The proposed model offers predictions for future research on language and brain function.