Preparation time and response complexity effects on stutterers' and nonstutterers' acoustic LRT

Area of Science:

• Speech-language pathology
• Neuroscience of speech disorders
• Acoustic phonetics

Background:

• Stuttering is a complex speech disorder characterized by disruptions in fluency.
• Previous research suggests motor control and timing deficits in individuals who stutter.
• Understanding preparation processes is crucial for characterizing stuttering.

Purpose of the Study:

• To investigate acoustic laryngeal reaction times (LRTs) in non-stutterers, mild stutterers, and severe stutterers.
• To examine the influence of response preparation and complexity on LRTs.
• To explore differences in preparation deficits among stutterer subgroups.

Main Methods:

• Recorded acoustic laryngeal reaction times (LRTs) for isolated vowels and VCV responses.
• Manipulated stimulus conditions to govern response preparation.
• Analyzed LRTs across different stutterer severity groups (non-stutterers, mild, severe).

Main Results:

• Severe stutterers consistently showed the longest LRTs, followed by mild stutterers and non-stutterers.
• Significant differences in LRTs were observed between groups, with greater differences between mild and severe stutterers.
• Non-stutterers were most adept at using preparation cues to reduce LRTs, while severe stutterers were least able.
• Only non-stutterers demonstrated significant within-group differences in response to varying response complexity.

Conclusions:

• Stutterer subgroups exhibit differential preparation deficits and motor initiation variability.
• LRTs are influenced by stuttering severity, preparation time, and response complexity.
• Findings support models of preparation processes and highlight subgroup-specific deficits in stuttering.