Name agreement in aphasia

Abstract

ABSTRACTBackground: Images are essential materials for assessment and rehabilitation in aphasia. Psycholinguistic research has identified name agreement (the degree to which different people agree on a particular name for a particular image) to be a strong predictor of picture naming in healthy individuals in a wide variety of languages. Despite its significance in naming performance and its impact across linguistic families, studies investigating the effects of name agreement in neuropsychological populations are limited. Determining the impact of name agreement in neuropsychological populations can inform us about lexical processing, which in turn can aid in development of improved assessment and rehabilitation materials.Aims: To compare the naming accuracy and error profile in naming high versus low name agreement (HighNA and LowNA) images in people with aphasia (PWA) and in healthy Adults (HA).Methods & Procedures: Participants were 10 PWA and 21 age- and gender-matched HA. Stimuli were black-and-white line drawings of 50 HighNA images (e.g., acorn, bell) and 50 LowNA images (e.g., jacket, mitten). The image sets were closely matched on a range of image and lexical variables. Participants were instructed to name the drawings using single words. Responses were coded into exclusive categories: correct, hesitations, alternate names, visual errors, semantic errors and omissions.Outcomes and Results: HighNA images were named more accurately than LowNA images; the HA group had higher accuracy than the PWA group; there was a significant interaction in which the name agreement effect was stronger in HA than in PWA. In individual analyses, 7 of 10 PWA participants showed the group pattern of higher accuracies for HighNA, whilst 3 PWA did not. HighNA and LowNA images gave rise to more alternate names in HA than in PWA. There were also fewer visual errors, and more omissions, in PWA than in HA, but only for LowNA items.Conclusions: Name agreement produced measurable differences in naming accuracy for both HA and PWA. PWA shows a reduced effect of name agreement and exhibit a different pattern of errors, compared to healthy controls. We speculate that in picture naming tasks, lower name agreement increases competitive lexical selection, which is difficult for PWA to resolve. In preparation of clinical materials, we need to be mindful of image properties. Future research should replicate our findings in a larger population, and a broader range of pathologies, as well as determine the executive mechanisms underpinning name agreement effects.