Atypical associations to abstract words in Broca's aphasia
Författare
Summary, in English
Introduction
Left frontal brain lesions are known to give rise to aphasia and impaired word associations. These associations have previously been difficult to analyze. We used a semantic space method to investigate associations to cue words. The degree of abstractness of the generated words and semantic similarity to the cue words were measured.
Method
Three subjects diagnosed with Broca’s aphasia and twelve control subjects associated freely to cue words. Results were evaluated with latent semantic analysis (LSA) applied to the Swedish Parole corpus.
Results
The aphasic subjects could be clearly distinguished from controls by a lower degree of abstractness in the words they generated. The aphasic group’s associations showed a negative correlation between semantic similarity to cue word and abstractness of cue word.
Conclusions
By developing novel semantic measures, we showed that Broca’s aphasic subjects’ word production was characterized by a low degree of abstractness and low degree of coherence in associations to abstract cue words. The results support models where meanings of concrete words are represented in neural networks involving perceptual and motor areas, whereas the meaning of abstract words is more dependent on connections to other word forms in the left frontal region. Semantic spaces can be used in future developments of evaluative tools for both diagnosis and research purposes.
Left frontal brain lesions are known to give rise to aphasia and impaired word associations. These associations have previously been difficult to analyze. We used a semantic space method to investigate associations to cue words. The degree of abstractness of the generated words and semantic similarity to the cue words were measured.
Method
Three subjects diagnosed with Broca’s aphasia and twelve control subjects associated freely to cue words. Results were evaluated with latent semantic analysis (LSA) applied to the Swedish Parole corpus.
Results
The aphasic subjects could be clearly distinguished from controls by a lower degree of abstractness in the words they generated. The aphasic group’s associations showed a negative correlation between semantic similarity to cue word and abstractness of cue word.
Conclusions
By developing novel semantic measures, we showed that Broca’s aphasic subjects’ word production was characterized by a low degree of abstractness and low degree of coherence in associations to abstract cue words. The results support models where meanings of concrete words are represented in neural networks involving perceptual and motor areas, whereas the meaning of abstract words is more dependent on connections to other word forms in the left frontal region. Semantic spaces can be used in future developments of evaluative tools for both diagnosis and research purposes.
Publiceringsår
2012
Språk
Engelska
Sidor
1068-1072
Publikation/Tidskrift/Serie
Cortex
Volym
48
Issue
8
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Neurology
Nyckelord
- aphasia
- latent semantic analysis
- LSA
- concreteness
- abstractness
Status
Published
Projekt
- Abstract, emotional and concrete words in the mental lexicon
- Thinking in Time: Cognition, Communication and Learning
ISBN/ISSN/Övrigt
- ISSN: 1973-8102