The Neural Circuitry Underlying the "Rhythm Effect" in Stuttering.

Area of Science:

• Neuroscience
• Speech and Hearing Sciences
• Cognitive Science

Background:

• Stuttering involves speech disfluencies, often reduced by rhythmic speech.
• The neural mechanisms behind rhythmic speech fluency are not fully understood.

Purpose of the Study:

• To investigate the neural basis of stuttering fluency induced by rhythmic speech using fMRI.
• To compare brain activity and connectivity in adults who stutter and controls during normal and rhythmic speech.

Main Methods:

• fMRI data collected from 16 adults who stutter and 17 controls reading sentences.
• Speech was either self-paced or synchronized to isochronous tones (rhythmic).
• Task activation and functional connectivity analyses were performed, controlling for speaking rate.

Main Results:

• Adults who stutter showed reduced disfluencies in the rhythmic condition.
• Rhythmic speech increased activation in speech sequencing, sensory feedback, and timing regions.
• Increased cerebellar connectivity and decreased fronto-cerebellar connectivity were observed in adults who stutter during rhythmic speech.

Conclusions:

• Rhythmic speech may activate a compensatory cerebellar timing system.
• This technique could modulate motor control and attention systems.
• The cerebellum shows potential as a therapeutic target for enhancing fluency in stuttering.