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A category-specific advantage for numbers in verbal short-term memory: Evidence from semantic dementia

Jones, Roy W.; Bateman, David; Jefferies, Elizabeth; Patterson, Karalyn; Lambon Ralph, Matthew A.


Roy W. Jones

David Bateman

Elizabeth Jefferies

Karalyn Patterson

Matthew A. Lambon Ralph


This study explored possible reasons for the striking difference between digit span and word span in patients with semantic dementia. Immediate serial recall (ISR) of number and non-number words was examined in four patients. For every case, the recall of single-digit numbers was normal whereas the recall of non-number words was impaired relative to controls. This difference extended to multi-digit numbers, and remained even when frequency, imageability, word length, set size and size of semantic category were matched for the numbers and words. The advantage for number words also applied to the patients' reading performance. Previous studies have suggested that semantic memory plays a critical role in verbal short-term memory (STM) and reading: patients with semantic dementia show superior recall and reading of words that are still relatively well known compared to previously known but now semantically degraded words. Additional assessments suggested that this semantic locus was the basis of the patients' category-specific advantage for numbers. Comprehension was considerably better for number than non-number words. Number knowledge may be relatively preserved in semantic dementia because the cortical atrophy underlying the condition typically spares the areas of the parietal lobes thought to be crucial in numerical cognition but involves the inferolateral temporal-lobes known to support general conceptual knowledge. © 2003 Elsevier Ltd. All rights reserved.


Jones, R. W., Bateman, D., Jefferies, E., Patterson, K., & Lambon Ralph, M. A. (2004). A category-specific advantage for numbers in verbal short-term memory: Evidence from semantic dementia. Neuropsychologia, 42(5), 639-660.

Journal Article Type Article
Publication Date Jan 1, 2004
Journal Neuropsychologia
Print ISSN 0028-3932
Publisher Elsevier
Peer Reviewed Not Peer Reviewed
Volume 42
Issue 5
Pages 639-660
Keywords semantic dementia, numbers, short-term memory
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