Neuropsychological models of stuttering--II. Interhemispheric interference

Area of Science:

• Neuroscience
• Speech and Language Pathology

Background:

• Stuttering is a complex speech disorder with debated neurological underpinnings.
• Previous research suggests potential differences in brain activity and interhemispheric communication in individuals who stutter.

Purpose of the Study:

• To investigate the impact of concurrent tasks on motor sequencing in adult male stutterers compared to fluent speakers.
• To explore the role of hemispheric interaction in the pathophysiology of stuttering.

Main Methods:

• Participants performed sequential finger tapping and single-finger tapping tasks with one hand.
• Concurrent paced tasks were administered to the contralateral hand.
• Interference effects on tapping performance were measured under specific hand conditions.

Main Results:

• Stutterers exhibited significantly greater interference on right-hand sequential tapping when performing a concurrent left-hand task compared to fluent speakers.
• This finding was specific to the condition involving right-hemisphere motor activity (tapping) and left-hemisphere cognitive processing (concurrent task).

Conclusions:

• The results support a neuropsychological model of stuttering.
• This model posits an enhanced vulnerability of the left hemisphere to interference from concurrent right-hemisphere activity in individuals who stutter.
• Further research is needed to elucidate the precise neural mechanisms involved.