Semantic memory is an amodal, dynamic system: Evidence from the interaction of naming and object use in semantic dementia

Classic neurological accounts and some contemporary theories of semantic memory assume that concepts are acquired through a learning process that draws together information experienced in each of our verbal and nonverbal modalities. These accounts embody three critical assumptions: semantic represen...

Full description

Saved in:
Bibliographic Details
Published in:Cognitive neuropsychology 2004-07, Vol.21 (5), p.513-527
Main Authors: Coccia, Michela, Bartolini, Marco, Luzzi, Simona, Provinciali, Leandro, Lambon Ralph, Matthew A.
Format: Article
Language:English
Subjects:
Adult and adolescent clinical studies
Anomia
Biological and medical sciences
Cognitive neuropsychology
Conceptual knowledge
Impairment
Medical sciences
Organic mental disorders. Neuropsychology
Psychology. Psychoanalysis. Psychiatry
Psychopathology. Psychiatry
Selective
Semantic dementia
Semantic memory
Theory
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Classic neurological accounts and some contemporary theories of semantic memory assume that concepts are acquired through a learning process that draws together information experienced in each of our verbal and nonverbal modalities. These accounts embody three critical assumptions: semantic representations are amodal; the mapping between surface form and meaning varies for different modalities; and the representations are dynamic. The influence of these three factors was revealed in data collected over a 4-year longitudinal period in two patients with semantic dementia. Semantic assessment revealed a parallel decline in verbal and nonverbal aspects of conceptual knowledge, reflecting a gradual degradation of a single amodal semantic system. As expected, when the patients' semantic impairment was mild, they presented with profound anomia but relatively preserved object use. Over time, performance on all semantic tasks including object use declined. High item-by-item consistency across these tasks was observed in all testing sessions. The impact of dynamic semantic representations was revealed by a striking clinical finding. Although unable to name many of the objects in isolation, their performance was significantly facilitated if they were asked to name while they demonstrated the use of each object. These results are discussed in the context of contemporary models of semantic memory.
ISSN:0264-3294
1464-0627
DOI:10.1080/02643290342000113