The influence of word frequency on semantic word substitutions in aphasic naming

Abstract

Background: Semantic word substitutions are frequent errors of aphasic speakers when naming a picture. The role of word frequency in the generation of these semantic errors provides an important testing ground for models of lexical access. The discrete two‐stage model of Levelt, Roelofs, and Meyer (1999) predicts that frequency should not play a role in semantic errors. In contrast, cascading and interactive models of lexical access allow for an influence of frequency on lexical selection. Aims: To assess the role of word frequency in the generation of semantic substitutions. Methods & Procedures: We re‐analysed a large corpus of aphasic semantic word substitutions in response to target words from carefully controlled semantic categories. Frequency of these errors was compared to randomly selected pseudo‐errors from the same semantic category. Outcomes & Results: Errors were more frequent than randomly selected competitors from the same semantic category. Conclusions: The results support interactive or cascading models of lexical access and speak against the discrete two‐stage model of lexical access. The data are discussed with regard to models of lexical access and to previous studies that failed to find a frequency effect for aphasic semantic naming errors. We would like to thank the aphasic patients for participating in this research, and the speech therapists for referring the patients to us. The idea to compare word frequency of the actual semantic errors and randomly chosen competitors came from an anonymous reviewer of a previous paper of our group. We are very grateful for this suggestion. We would like to thank Myrna Schwartz and an anonymous reviewer for helpful comments on a previous version of this paper.