Selective enhancement of functional connectivity in the left prefrontal cortex during sentence processing

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Psycholinguistics

Background:

• Understanding brain mechanisms underlying language processing is crucial.
• Functional connectivity analysis reveals how different brain regions interact.
• The prefrontal cortex plays a key role in complex cognitive functions, including language.

Purpose of the Study:

• To investigate functional connectivity between the left inferior frontal gyrus (L. F3t/F3O) and left precentral sulcus (L. PrCS).
• To determine if this connectivity differs between sentence comprehension and lexical decision tasks.
• To explore the role of prefrontal cortex functional connectivity in syntactic integration.

Main Methods:

• Functional magnetic resonance imaging (fMRI) data were analyzed using correlation analyses.
• Temporal correlations of fMRI signals were examined between L. F3t/F3O and L. PrCS.
• Analyses were conducted during auditory and visual sentence comprehension and lexical decision tasks.

Main Results:

• Reciprocal functional connectivity between L. F3t/F3O and L. PrCS was significantly enhanced during sentence processing.
• This enhancement was observed under both auditory and visual conditions.
• Correlated regions were predominantly located in the left prefrontal cortex during sentence tasks, but not lexical tasks.

Conclusions:

• Functional connectivity within the left prefrontal cortex is selectively enhanced for sentence processing.
• This selective enhancement may support the integration of lexico-semantic information using syntactic cues.
• Findings highlight the role of specific prefrontal circuits in grammatical processing.