Models, theories and heuristics in apraxia of speech

This paper presents an examination of efforts to explain acquired apraxia of speech. The history of the disorder is sketched, its relation to other forms of apraxia and aphasia is discussed, and the evolutionary relationship between speech and action is addressed. Most research hes been focused on whether apraxia of speech is best accounted for in terms of impairments at either an abstract-phonological level or a concrete-phonetic processing level, and the sum of the research concludes that it straddles traditional linguistic divides; it is an impairment in the transforming of phonological representation into phonetic fact. The issue is essentially a variant of the mind-body problem. Recent developments in phonological theory point to the importance of a less abstract phonology which is phonetically derived, phonetically constrained and phonetically dependent. Apraxia of speech provides a basis for an improved understanding of the nature of the control of speech processing.