ABSTRACT
It was argued at the beginning of Chapter 7 that language and motor processes are independent. Thus, language or motor factors alone may affect stuttering. When a language factor affects stuttering, speech motor output also will be influenced. This is because if language processing is in error, that error will propagate through to production, although explaining how higher order linguistic errors manifest themselves at the motor level is not a trivial problem. Therefore, to obtain evidence that the motor factors affect stuttering, it is necessary to ensure that the effects are not epiphenomena of a language-processing problem. People who take the view that stuttering is exclusively language-based attribute all observed motor deficits to a passive motor response associated with the language deficit (Levelt, 1989). This view is further evaluated in Chapter 10. The same passivity idea also has been applied in the field of stuttering, as illustrated by Bernstein Ratner and Wijnen (2007). They indicate that the motor processes passively translate linguistic input to speech output when they state in relation to stuttering “what we believe to be a problem in language encoding can lead to apparent motor execution difficulties.”
