Bridging the divide between laboratory and "real world" in stuttering

Area of Science:

• Speech-language pathology
• Neuroscience of speech production
• Psycholinguistics

Background:

• Stuttering is a speech disorder characterized by disruptions in fluency.
• Observed fluency differences between clinical/laboratory settings and real-world communication are significant.
• Existing theories often focus on speech motor control deficits.

Purpose of the Study:

• To review literature explaining why stutterers exhibit greater fluency in laboratory/clinical settings compared to everyday situations.
• To propose a model where attentional focus on message content and social dynamics in real-world communication impacts speech production.
• To identify the specific mechanisms underlying stuttering during speech production.

Main Methods:

• Systematic review of existing literature on stuttering, speech production, and attention.
• Analysis of theoretical frameworks explaining fluency variations in different speaking environments.
• Synthesis of evidence to support a cognitive-attentional model of stuttering.

Main Results:

• In real-world settings, high personal stakes and interpersonal dynamics redirect attention to message content, promoting automatic speech processes (speech concatenation).
• In laboratory/clinical settings, reduced stakes and less complex interpersonal dynamics allow for greater conscious focus on speech motor planning (articulation and prosody).
• Speech construction (real-time motor plan preparation) appears incompatible with stuttering, while slight delays in retrieving motor plans during speech concatenation are implicated as the direct cause.

Conclusions:

• Stuttering frequency is modulated by the cognitive and attentional demands of the speaking situation.
• The proposed model highlights the interplay between cognitive factors, attentional allocation, and speech motor control in stuttering.
• Understanding these mechanisms offers new avenues for therapeutic interventions targeting attentional strategies and speech production.