Phonemic retrieval in anomic aphasia: A case study

Abstract

Phonemic retrieval deficits may underly some of the phonological production errors of aphasic adults in immediate repetition. This study examined the influence of real and nonsense distractor words on the retrieval of real and nonsense target words in an anomic aphasic woman (RL) with a phonological retrieval deficit but relatively preserved immediate memory, using a deferred repetition paradigm. The experimental task involved presentation of pairs of Consonant-Vowel-Consonant (CVC) stimuli, each pair consisting of a target word and a distractor word. Target and distractor words were either real or nonsense words, with distractors varying in their phonetic similarity to target words. RL was required to retrieve target words following presentation of real and nonsense distractors. The number of errors produced on deferred target repetition based on distractor type and error type were determined. RL's performance was influenced by the lexical nature of the target, the phonetic similarity/dissimilarity between the target and distractor, as well as the lexical relationship between the target and distractor. RL produced significantly more errors on nonsense than real target words, regardless of distractor type. Errors for retrieving real target words were significantly prevalent in two conditions: when target and distractor were real words that were very phonetically similar and when real targets were paired with nonsense distractors that were completely phonetically dissimilar. These two conditions resulted in different types of errors: phonetic similarity errors reflect segmental interference of the distractor whereas phonetic dissimilarity reflect resource allocation problems in retrieving novel information. These performance patterns provide additional insight into the phonological retrieval deficit underlying anomic aphasia.