Theta Modulated Neural Phase Coherence Facilitates Speech Fluency in Adults Who Stutter

Area of Science:

• Neuroscience
• Speech and Language Sciences
• Cognitive Science

Background:

• Adults who stutter (AWS) exhibit distinct neural phase coherence patterns in the speech motor system before disfluencies.
• Phase coherence is crucial for understanding neural communication within brain networks relevant to stuttering.

Purpose of the Study:

• To investigate the oscillatory cortical dynamics preceding fluent speech in adults who stutter (AWS) compared to adults who do not stutter (AWNS).
• To identify neural markers that differentiate fluent speech preparation in AWS and AWNS.

Main Methods:

• Utilized electroencephalographic (EEG) techniques to record brain activity.
• Examined oscillatory cortical dynamics during a single-word delayed reading task.
• Analyzed phase coherence and spectral power in different frequency bands (theta, beta, gamma).

Main Results:

• AWS showed decreased theta-gamma phase coherence and increased theta-beta coherence preceding fluent speech compared to AWNS.
• AWS exhibited higher spectral power in the beta and gamma bands before fluent utterances.
• These findings indicate altered neural communication during speech planning in AWS.

Conclusions:

• Adults who stutter (AWS) display atypical neural communication patterns even during fluent speech preparation.
• Evidence suggests an atypical allocation of feedforward control in AWS, even before fluent utterances.
• Altered oscillatory dynamics provide insights into the neural basis of stuttering.