A theory of neuropsycholinguistic function in stuttering.

A theory of neurolinguistic function is proposed to explain fluency and the production of stuttered and nonstuttered speech disruptions. Central to the theory is the idea that speech involves linguistic and paralinguistic components, each of which is processed by different neural systems that converge on a common output system. Fluent speech requires that these components be integrated in synchrony. When they are dyssynchronous, the result can be either nonstuttered disfluency or stuttering, depending on time pressure. Time pressure is defined as the speaker's need to begin, continue, or accelerate an utterance. Nonstuttered disfluency results when the linguistic and paralinguistic components are dyssynchronous and the speaker is not under time pressure. Stuttering results when the speaker is under time pressure and is relatively unaware of the cause of dyssynchrony. Both of these factors are necessary for the identification of the phenomenon of stuttering. Stuttering is defined as disruption of speech that is experienced by the speaker as a loss of control. The theory presented here accounts for both the disruption and the experienced loss of control.