Functional connectivity between face-movement and speech-intelligibility areas during auditory-only speech...

Area of Science:

• Neuroscience
• Cognitive Science
• Auditory Perception

Background:

• Auditory speech recognition is crucial for communication.
• Internal simulation of visual speech (talking faces) may aid auditory comprehension.
• Brain regions processing auditory speech are hypothesized to interact with visual face-movement areas.

Purpose of the Study:

• To investigate if learned visual information about speakers enhances auditory-only speech recognition.
• To determine if functional connectivity between face-movement sensitive areas and auditory speech areas increases with visual familiarity.
• To examine this interaction in both typical individuals and those with developmental prosopagnosia.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity.
• Participants learned to associate six speakers' faces with their voices.
• Connectivity analyses were performed during auditory-only speech and voice recognition tasks.

Main Results:

• Increased functional connectivity was observed between the posterior superior temporal sulcus (STS) and anterior STS during speech recognition when speakers were visually familiar.
• This effect was present regardless of whether participants had typical face recognition abilities or developmental prosopagnosia.
• No significant differences were found between typical participants and those with developmental prosopagnosia.

Conclusions:

• Learned visual information about a speaker's face is integrated into auditory-only speech processing.
• This integration is mediated by increased functional connectivity between face-movement sensitive visual areas and auditory speech-sensitive areas.
• The findings support the role of the superior temporal sulcus (STS) in integrating visual and auditory speech information for enhanced comprehension.