Articulatory consequences of Parkinson's disease: Perspectives from two modalities

Language production involves complex yet productively varying motor behavio r. Rule-governed combinations yield a finite set of formational units combi ned in an infinite number of ways. The creativity of language ensures that no particular articulation will be highly automatized. Linguistic articulat ion is highly complex and varied. As such, it differs from the other more a utomatized motor behaviors typically studied such as learned movements in a praxia studies or repetitive behavior as occurs in walking or other everyda y activities. Language also strives to maintain a balance between ease of a rticulation and ease of perception, while maintaining linguistically releva nt distinctions. We report here a number of studies on the articulatory con sequences of Parkinson's disease (PD) in the spoken and signed modalities. Our goal is to highlight the commonalities and distinctions between the two modalities of speech and sign that will allow us to better understand the impingements of PD on language production in general. (C) 1999 Academic Pre ss.