DIFFERENTIAL RECOVERY FROM IMPAIRMENT TO THE PHONOLOGICAL LEXICON

Word production was examined in four aphasics diagnosed acutely with n eologistic jargon and who displayed impairment to the lexical stage of phonological production (Kohn & Smith, 1993, 1994a). To investigate t he major source of their nonword errors (i.e., neologisms, phonemic pa raphasias), single word production was tested at three different times over the first 6 months postonset, with one subject receiving additio nal testing at 14 months postonset. Two subjects showed signs of recov ery to the phonological output system with respect to: (1) improved wo rd production scores, (2) increased frequency of phonemic paraphasias versus neologisms, and (3) increased production of target phonemes. Th ese subjects also displayed above-chance production of target phonemes and no significant tendency to perseverate phonemes across picture-na ming trials. It was argued that this pattern reflects a resolving dist urbance in retrieving entries from the phonological lexicon. The other two subjects showed no improvement in word production. They also cons istently produced target phonemes at chance levels and had a tendency to perseverate phonemes across picture-naming trials. This static patt ern of performance was considered to reflect loss of information from the phonological lexicon. The neuroanatomical damage sustained by each case was consistent with these two recovery patterns. (C) 1996 Academ ic Press, Inc.