Timing variability of sensorimotor integration during vocalization in individuals who stutter

Area of Science:

• Neuroscience
• Speech-language pathology
• Auditory processing

Background:

• Persistent developmental stuttering affects approximately 1% of adults.
• Stuttering is hypothesized to involve difficulties in sensorimotor integration.
• Individuals who stutter exhibit altered responses to auditory feedback during speech.

Purpose of the Study:

• To investigate how adults who stutter respond to pitch-shifted auditory feedback.
• To examine the compensatory mechanisms in vocal production related to auditory feedback alterations.
• To explore the role of sensorimotor integration timing in stuttering.

Main Methods:

• Participants sustained the vowel /a/ while receiving real-time auditory feedback of their voice.
• Auditory feedback pitch was briefly shifted up or down by 100 cents.
• Vocal production adjustments were measured to assess compensatory responses.

Main Results:

• Adults who stutter demonstrated smaller average compensatory responses compared to controls.
• Fewer trials with robust corrective responses were observed in adults who stutter.
• The timing of compensatory responses in adults who stutter was more variable.

Conclusions:

• Dysfunctional sensorimotor integration in stuttering is characterized by timing variability.
• Reduced coupling between auditory and speech motor systems may underlie stuttering.
• These findings offer insights into the neural mechanisms of stuttering.