Lost in semantic space: a multi-modal, non-verbal assessment of feature knowledge in semantic dementia.

Full Abstract

A novel, non-verbal test of semantic feature knowledge is introduced, enabling subordinate knowledge of four important concept attributes--colour, sound, environmental context and motion--to be individually probed. This methodology provides more specific information than existing non-verbal semantic tests about the status of attribute knowledge relating to individual concept representations. Performance on this test of a group of 12 patients with semantic dementia (10 male, mean age: 64.4 years) correlated strongly with their scores on more conventional tests of semantic memory, such as naming and word-to-picture matching. The test's overlapping structure, in which individual concepts were probed in two, three or all four modalities, provided evidence of performance consistency on individual items between feature conditions. Group and individual analyses revealed little evidence for differential performance across the four feature conditions, though sound and colour correlated most strongly, and motion least strongly, with other semantic tasks, and patients were less accurate on the motion features of living than non-living concepts (with no such conceptual domain differences in the other conditions). The results are discussed in the context of their implications for the place of semantic dementia within the classification of progressive aphasic syndromes, and for contemporary models of semantic representation and organization.

Author information

Author/s: Garrard, Peter (P); Carroll, Erin (E);

Affiliation: University College London, Institute of Cognitive Neuroscience, Alexandra House, Hampstead, London, UK. p.garrard(-atsign-)ucl.ac.uk

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Brain : a journal of neurology (Brain), published in England. (Language: eng)

Reference: 2006-May; vol 129 (issue Pt 5) : pp 1152-63

Dates: Created 2006/04/21; Completed 2006/05/31; Revised 2006/11/15;

PMID: 16585052, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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