Effective neural connectivity deficits during speech auditory feedback processing in post-stroke aphasia: An fMRI...

Area of Science:

• Neuroscience
• Speech-language pathology

Background:

• Post-stroke aphasia causes significant speech and auditory processing impairments.
• Understanding neural connectivity in sensorimotor networks is crucial for aphasia research.

Purpose of the Study:

• Investigate neural connectivity within sensorimotor networks in individuals with post-stroke aphasia.
• Compare connectivity patterns between aphasia patients and neurotypical controls.

Main Methods:

• Functional magnetic resonance imaging (fMRI) during speaking and listening tasks.
• Altered auditory feedback (pitch-shifted) was used.
• Dynamic causal modeling and parametric empirical Bayes for effective connectivity analysis.

Main Results:

• Significant alterations in intrinsic and extrinsic connectivity were found in the aphasia group.
• Decreased connectivity during listening and mixed modulation during speaking were observed.
• Increased self-inhibition in the left precentral gyrus (PrCG) and compensatory reorganization in right-hemisphere connectivity were noted.

Conclusions:

• Post-stroke aphasia involves impaired and redistributed bilateral speech networks.
• Findings emphasize the importance of examining both receptive and productive speech aspects in sensorimotor networks for treatment.
• Altered connectivity suggests impaired feedforward mechanisms and potential compensatory processes.