Phonemic retrieval in conduction aphasia and broca's aphasia with apraxia of speech: underlying processes

Abstract

Phonemic retrieval deficits may underly some of the phonological production errors of aphasic adults. This study examined the retrieval of real and nonsense distractor words in Broca's aphasic adults with apraxia of speech and conduction aphasic adults using a deferred repetition paradigm. A non brain damaged group also participated in the investigation. The task involved presentation of 70 pairs of CVC stimuli, each pair consisting of a target word and distractor word. Distractors varied in lexicalness (real versus nonsense) and phonetic similarity to target words. The mean proportion of errors on deferred recall based on target/distractor pairing and error type were determined for each group. The results revealed that: (1) brain damaged adults produced significantly more errors than non brain damaged subjects; (2) all groups showed a lexical target effect with more errors produced on nonsense than real target words; (3) Broca's aphasic adults exhibited a greater lexical distractor effect with more errors on targets paired with nonsense distractors; and (4) conduction aphasic adults displayed a greater phonetic similarity effect between target and distractor, with more errors on deferred retrieval of targets when the distractor was phonetically similar to the target.