The differential dependence of abstract and concrete words upon associative and similarity-based information: Complementary semantic interference and facilitation effects

Abstract

We report mirror-image effects of interference and facilitation in the semantic processing of identical sets of abstract and concrete words in a patient F.B.I. with global aphasia following a large left middle cerebral artery stroke. Interference was elicited when the tasks involved comprehending the spoken form of each word, but facilitation was found when the patient read aloud the written forms of the same words. More importantly, irrespective of whether the dynamic effect was one of facilitation or interference, effects of semantic association were observed for abstract words, whilst effects primarily of semantic similarity were observed for concrete words. These results offer further neuropsychological evidence that the more abstract a word, the greater its dependence upon associative information and the smaller its dependence upon similarity-based information. The investigations also contribute to a converging body of evidence that suggests that this theory generalizes across different experimental paradigms, stimuli, and participants and also across different cognitive processes within individual patients. The data support a graded rather than binary or ungraded model of the relationships between concreteness, association, and similarity, and the basis for concrete words’ greater dependence upon similarity-based information is discussed in terms of the development of taxonomic structures and categorical thought in young children.

Keywords:

• Abstract and concrete knowledge
• Semantic processing
• Verbal comprehension
• Deep-phonological dyslexia
• Stroke aphasia

Acknowledgments

We are grateful to Martin Rossor for his support of this work. We would like to thank David Cohen and the therapists on the Harrow Stroke Unit at Northwick Park Hospital for allowing us to work with a patient under their care. We are grateful to Jason Warren for his opinion on the neuroimaging data, to Sue Gathercole for her helpful discussion of these topics, and to Matt Lambon Ralph and Gabriella Vigliocco for their insightful comments on an earlier version of this paper. This work was undertaken at University College London Hospitals/University College London (UCLH/UCL) who received a proportion of funding from the Department of Health's National Institute for Health Research (NIHR) Biomedical Research Centres funding scheme. The Dementia Research Centre is an Alzheimer's Research Trust Co-ordinating Centre. This work was supported by a Research Fellowship to S.C. and an equipment grant from the Alzheimer's Research Trust.

Notes

¹ For Set A stimuli, concreteness ratings were available for only 80% of words, and AoA ratings were available for only 89% of words. Consequently, 10 healthy control participants (mean age = 31.0 years, SD = 6.8) were presented with the missing items in the same randomized order and were asked to provide concreteness and/or AoA ratings. The instructions for the concreteness ratings followed Paivio et al. (1968), with participants being requested to rate each word on a Likert scale from 1 (abstract) to 7 (concrete). The instructions for the AoA ratings followed Gilhooly and Logie (1980), with participants being asked to rate the age at which they had learned the word on a Likert scale from 1 (0–2 years) to 7 (13 years or more). The mean ratings for each item were calculated and then multiplied by 100 in order to match the 100–700 scale provided by the MRC Psycholinguistic Database.

² In an attempt to prevent simple repetition priming, the original unrelated word lists were checked and where necessary rearranged to ensure that related and unrelated arrays in any given condition (e.g., abstract association) could be administered over two sessions without any individual words occurring more than once in a single session.