Lexical retrieval mechanisms underlying whole-word perseveration errors in anemic aphasia

In this study, factors that influence the occurrence of perseverative and non-perseverative word substitution errors produced by three subjects on the Philadelphia Naming Test are examined. Specifically, target-error similarity (semantic and/or phonological) is shown to influence the occurrence of both perseverative and non-perseverative errors within a subject's error profile. In a second analysis, an interaction between target-error similarity and processing factors (recency and frequency of prior production) are identified on the overall probability that word perseverations will occur. Two accounts of perseveration are considered in the discussion of these findings: (1) perseveration results from a failure to inhibit a prior response; and (2) perseveration results from a summation of residual priming activation of a prior response and spreading activation from the representation of the current target word.