Rhythmic tapping difficulties in adults who stutter: A deficit in beat perception, motor execution, or sensorimotor...

Area of Science:

• Neuroscience
• Speech and Hearing Science
• Motor Control

Background:

• Stuttering is a complex speech disorder potentially involving motor control deficits.
• Rhythmic abilities and sensorimotor integration are crucial for fluent speech production.
• Understanding rhythmic impairments in people who stutter (PWS) can elucidate underlying mechanisms.

Purpose of the Study:

• To investigate rhythmic abilities in adults who stutter (PWS).
• To identify potential impairments in beat perception/reproduction, movement execution, and sensorimotor integration in PWS.
• To compare rhythmic task performance between PWS and typically developing controls (PNS).

Main Methods:

• 16 adults who stutter (PWS) and 16 matched controls (PNS) performed five rhythmic tasks.
• Tasks included synchronization (isochronous and non-isochronous patterns), reaction to unpredictable patterns, and reproduction of learned patterns.
• Finger tapping behavior was analyzed for accuracy, variability, and asynchrony.

Main Results:

• PWS exhibited increased tapping variability and larger negative mean asynchronies compared to PNS during synchronization tasks.
• While PWS could reproduce rhythmic patterns accurately, their variability was higher, indicating production rather than perception deficits.
• Sensorimotor learning and task complexity did not significantly alter group differences in rhythmic performance.

Conclusions:

• Findings support a deficit in neuronal oscillator coupling for rhythmic pattern production in PWS, not perception.
• PWS demonstrate delayed multi-modal feedback processing.
• These motor control and processing differences may contribute to stuttering.