DISTINCTIONS BETWEEN 2 PHONOLOGICAL OUTPUT DEFICITS

Two aphasics with a similar level of phonological production difficult y are compared to distinguish the properties of disruption to two stag es in the phonological system for producing single words: activation o f stored lexical-phonological representations versus construction of p honemic representations. A set of distinguishing behavioral features f or breakdown at each stage is generated on the basis of a model of sin gle word production. Important variables for analyzing output include: (a) the unit of phonological encoding (morpheme versus syllable), (b) the phonemic relationship between targets and responses, (c) the effe cts of target consonant-vowel (CV) structure, and (d) the level of pse udoword production. On a set of production tests, the expected behavio ral pattern for impaired lexical-phonological activation was displayed by LW, while the expected behavioral pattern for impaired phonemic pl anning was displayed by CM.