Cognitive neuropsychological approaches to word production in aphasia: Beyond boxes and arrows

Abstract

Background: The cognitive neuropsychological approach aims to describe aphasic disorders of word production by identifying the specific cognitive process(es) that are impaired in each individual. This approach is becoming increasingly influential in the assessment, investigation, and treatment of word production difficulties in aphasia. The classical cognitive neuropsychological approach, with its signature box‐and‐arrow diagrams, is now highly familiar to most aphasiologists. However, more recent theoretical innovations are much less widely known. There is a need for an up‐to‐date review that summarises the current thinking in this field in a way that is accessible to non‐specialists. This article is adapted from material to appear in the forthcoming book Cognitive Neuropsychology: Exploring the Mind Through Brain Dysfunction by C. E. Wilshire, to be published by Psychology Press. The author would like to thank Kate Smith for her feedback on an earlier version of the manuscript and for her assistance in preparing the manuscript. I am especially grateful to Kate for creating the figures that appear in this article. Aims: The present article reviews recent theoretical innovations in the cognitive neuropsychology of word production. It aims to demonstrate how these have led to a more dynamic view of word production that emphasises processes rather than representations, and offers new ways of understanding the diversity of word production impairments seen in aphasia. Main Contribution: Starting from the earliest box‐and‐arrow theories, the article describes how cognitive neuropsychological accounts of aphasic word production have evolved as a result of cross‐pollination from other fields, particularly cognitive psychology. Through the use of specific examples, the review outlines some of the ways in which newer theoretical accounts for particular types of disorders differ from more classical explanations. The article also discusses some recent empirical approaches that have been inspired by the new theoretical accounts, including computer simulation studies of patterns of naming errors. It also illustrates how the tighter relationship between theories of normal and impaired language processing has increased the potential contribution of aphasia studies to language research more generally. The review closes with a discussion of some current and future issues in the cognitive neuropsychology of language, including those relating to the degree of discreteness/continuity in the language system, and the relationship between production and comprehension in aphasia. It also comments upon some recent research regarding the role of sentence‐level and other contextual factors in word production, which may lead to a better understanding of the kinds of language production difficulties that are observed in nonfluent aphasia. Conclusions: The argument that emerges from the review is that more recent cognitive neuropsychological approaches to word production disorders cannot be understood as mere extensions or refinements of the classical box‐and‐arrow theories. Rather, they offer a fundamentally different view of word production, and this has important implications for both researchers and practitioners in the field.