Brain networks involved in accented speech processing

Area of Science:

• Neuroscience
• Cognitive Science
• Psycholinguistics

Background:

• Accented speech processing (ASP) research has been limited by intelligibility issues.
• Previous studies often focused on isolated brain regions rather than networks.

Purpose of the Study:

• To investigate the neural correlates of accented speech processing using fMRI.
• To identify brain networks involved in processing speech with regional accents.
• To explore the influence of accent familiarity on neural responses.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed.
• Independent component analysis (ICA) was used to identify brain networks.
• Two regional Spanish accents (Latin American and Castilian) with differing prosody but similar phonetics were used to maintain intelligibility.

Main Results:

• Accented speech processing engaged a network including the cerebellum, putamen, and thalamus, crucial for prosody.
• Anterior fronto-temporal areas and the inferior frontal gyrus, involved in lexical-semantic and executive functions, were also recruited.
• Domain-general networks (dorsal attentional, default mode, salience) supported cognitive demands and salient event processing.
• The reward network exhibited a preference for the native accent, indicating a link to social belonging.

Conclusions:

• Accented speech processing relies on integrated brain networks rather than isolated regions.
• Cognitive control and salience detection networks play a significant role in managing accented speech.
• Neural responses to accents are influenced by social factors, such as a sense of belonging to a native group.