Affiliations: Cerebral Function Unit, Greater Manchester
Neuroscience Centre, Salford Royal Foundation Trust, Salford, UK | Mental Health and Neurodegeneration Research Group,
Faculty of Medicine and Human Sciences, University of Manchester, Manchester, UK
Note: [] Corresponding author: Professor Julie S. Snowden, Cerebral
Function Unit, Greater Manchester Neuroscience Centre, Salford Royal Foundation
Trust, Salford M6 8HD, UK. Tel.: +44 161 206 2561; Fax: +44 161 206 0388;
E-mail: julie.snowden@manchester.ac.uk
Abstract: It is generally accepted that the anterior temporal lobes support
knowledge of famous people. The specific roles of the right and left temporal
lobe remain a subject of debate, with some studies suggesting differential
roles based on modality (visual versus verbal information) and others category
(person knowledge versus general semantics). The present study re-examined
performance of semantic dementia patients with predominantly right and
predominantly left temporal lobe atrophy on famous face, famous name and
general semantic tasks, with the specific aim of testing the hypothesis that
the right temporal lobe has a privileged role for person knowledge and the left
temporal lobe for general semantic knowledge. Comparisons of performance
rankings across tasks showed no evidence to support this hypothesis. By
contrast, there was robust evidence from naming, identification and familiarity
measures for modality effects: right-sided atrophy being associated with
relatively greater impairment for faces and visual tasks and left-sided atrophy
for names and verbal tasks. A double dissociation in test scores in two
patients reinforced these findings. The data present a challenge for the
influential `semantic hub' model, which views the anterior temporal lobes as an
area of convergence in which semantic information is represented in amodal form.
