Plural dominance effects in picture naming for language-impaired and unimpaired speakers: a comparison

This study looks at the effect of frequency on plural processing. Plural-dominant plural forms (e.g. ‘ears’, ‘mice’) are higher in frequency compared to their singular forms (‘ear’, ‘mouse’), whereas singular-dominant plural forms (e.g. ‘clocks’) are lower in frequency compared to their singular forms. While plural dominance effects have been found in comprehension tasks (such as lexical decision) in healthy speakers, production tasks such as picture naming have been neglected to date as a tool of investigation. We explored the effect of plural dominance by comparing picture naming performance from brain-impaired with unimpaired speakers, and relating the outcome to current theories of morphological processing. Two Australian-English men with aphasia and 40 healthy, native English speakers named sets of pictures corresponding to plural-dominant and singular-dominant nouns, matched for frequency, name agreement, age of acquisition, etc. Both people with aphasia showed a significant plural advantage in naming accuracy for the plural-dominant plural stimuli compared to their singulars. In contrast, the healthy speakers exhibited only a trend for faster production times for plural-dominant plurals compared to their singulars. Additional analyses (mixed modeling) will be reported and the issue of controlling for recognition time in picture naming studies will be discussed.