Affiliations: Dementia Research Centre, Department of
Neurodegeneration, UCL Institute of Neurology, University College London, London, UK
Note: [] Address for correspondence: Dr. Sebastian Crutch, Dementia
Research Centre, Box 16, National Hospital for Neurology and Neurosurgery,
Queen Square, London, WC1N 3BG, UK. Tel.: +44 8451 555 000 ext. 723113; Fax:
+44 20 7676 2066; E-mail: [email protected]
Abstract: We report the investigation of the organisation of proper names in
two aphasic patients (NBC and FBI). The performance of both patients on spoken
word to written word matching tasks was inconsistent, affected by presentation
rate and semantic relatedness of the competing responses, all hallmarks of a
refractory semantic access dysphasia. In a series of experiments we explored
the semantic relatedness effects within their proper name vocabulary, including
brand names and person names. First we demonstrated the interaction between
very fine grain organisation and personal experience, with one patient with a
special interest in the cinema demonstrating higher error rates when
identifying the names of actors working in a similar film genre (e.g. action
movies: Arnold Schwarzenegger, Bruce Willis, Sylvester Stallone, Mel Gibson)
than those working in different genres (e.g. Arnold Schwarzenegger, Gregory
Peck, Robin Williams, Gene Kelly). Second we compared directly two potential
principles of semantic organisation – taxonomic and thematic. Furthermore we
considered these principles of organisation in the context of the individuals'
personal knowledge base. We selected topics matching the interests and
experience of each patient, namely cinema and literature (NBC) and naval
history (FBI). The stimulus items were arranged in taxonomic arrays (e.g. Jane
Austen, Emily Bronte, Agatha Christie), thematic arrays (e.g. Jane Austen,
Pride and Prejudice, Mr Darcy), and unrelated arrays (e.g. Jane Austen,
Wuthering Heights, Hercule Poirot). We documented that different patterns of
taxonomic and thematic organisation were constrained by whether the individual
has limited knowledge, moderate knowledge or detailed knowledge of a particular
vocabulary. It is suggested that moderate proper name knowledge is primarily
organised by taxonomy whereas extensive experience results in a more detailed
knowledge base in which theme is a powerful organising principle.
