LEVELS OF MORPHOLOGICAL DEFICIT - INDICATIONS FROM INFLECTIONAL REGULARITY

A language impairment that affects the production of inflected and/or derived words may result from a deficit that specifically affects morp hological processing mechanisms. but it might also arise from whole-wo rd processing failures as well (Badecker & Caramazza, 1987: Funnell, 1 987). However, to motivate a true morphological impairment, the defici t must be understood in terms of one or more different levels of morph ological structure. Minimally, we can distinguish a word's morphosynta ctic representation from its morphophonological representation. In the single-case study reported here a deficit affecting the representatio n or processing of morphosyntactic representations is motivated. A cri tical part of the argument is that the deficit affects both regular an d irregular inflection, and that no whole-word processing deficit can account for the particular pattern observed in this patient. (C) 1997 Academic Press.