Comprehension of Concrete and Abstract Words in Semantic Dementia

TY - JOUR

T1 - Comprehension of Concrete and Abstract Words in Semantic Dementia

AU - Jefferies, Elizabeth

AU - Patterson, Karalyn

AU - Jones, Roy W.

AU - Ralph, Matthew A. Lambon

PY - 2009/7

Y1 - 2009/7

N2 - The vast majority of brain-injured patients with semantic impairment have better comprehension of concrete than abstract words. In contrast, several patients with semantic dementia (SD), who show circumscribed atrophy of the anterior temporal lobes bilaterally. have been reported to show reverse imageability effects. that is. relative preservation of abstract knowledge. Although these reports largely concern individual patients, some researchers have recently proposed that superior comprehension of abstract concepts is a characteristic feature of SD. This would imply that the anterior temporal lobes are particularly crucial for processing sensory aspects of semantic knowledge, which are associated with concrete not abstract concepts. However, functional neuroimaging studies of healthy participants do not unequivocally predict reverse imageability effects in SD because the temporal poles sometimes show greater activation for more abstract concepts. The authors examined a case-series of 11 SD patients on a synonym judgment test that orthogonally varied the frequency and imageability of the items. All patients had higher success rates for more imageable as well as more frequent words, Suggesting that (1) the anterior temporal lobes underpin semantic knowledge for both concrete and abstract concepts, (2) more imageable items-perhaps because of their richer multimodal representations-are typically more robust in the face of global semantic degradation and (3) reverse imageability effects are not a characteristic feature of SD.

AB - The vast majority of brain-injured patients with semantic impairment have better comprehension of concrete than abstract words. In contrast, several patients with semantic dementia (SD), who show circumscribed atrophy of the anterior temporal lobes bilaterally. have been reported to show reverse imageability effects. that is. relative preservation of abstract knowledge. Although these reports largely concern individual patients, some researchers have recently proposed that superior comprehension of abstract concepts is a characteristic feature of SD. This would imply that the anterior temporal lobes are particularly crucial for processing sensory aspects of semantic knowledge, which are associated with concrete not abstract concepts. However, functional neuroimaging studies of healthy participants do not unequivocally predict reverse imageability effects in SD because the temporal poles sometimes show greater activation for more abstract concepts. The authors examined a case-series of 11 SD patients on a synonym judgment test that orthogonally varied the frequency and imageability of the items. All patients had higher success rates for more imageable as well as more frequent words, Suggesting that (1) the anterior temporal lobes underpin semantic knowledge for both concrete and abstract concepts, (2) more imageable items-perhaps because of their richer multimodal representations-are typically more robust in the face of global semantic degradation and (3) reverse imageability effects are not a characteristic feature of SD.

KW - semantic dementia

KW - imageability

KW - concreteness

KW - anterior temporal

KW - synonym judgment

KW - TEMPORAL-LOBE ATROPHY

KW - INTELLIGIBLE SPEECH

KW - PROCESSING CONCRETE

KW - OBJECT RECOGNITION

KW - ALZHEIMERS-DISEASE

KW - DEEP DYSLEXIA

KW - MEMORY

KW - IMAGEABILITY

KW - IMPAIRMENT

KW - ASSOCIATION

UR - http://www.scopus.com/inward/record.url?scp=67650102197&partnerID=8YFLogxK

U2 - 10.1037/a0015452

DO - 10.1037/a0015452

M3 - Article

SN - 0894-4105

VL - 23

SP - 492

EP - 499

JO - Neuropsychology

JF - Neuropsychology

IS - 4

ER -