ABSTRACT
The computational simulation of the conceptual structure account revealed an interaction between severity of damage throughout the semantic system and the direction of impairment. Living things were more impaired at most levels of damage, but when damage was very severe and overall performance very inaccurate, living things had a slight advantage over artefacts. We suggest that this is due to the large number of highly intercorrelated shared properties for living things, which is the only information that can withstand this degree of damage, allowing a small percentage of living things trials to be correct (see Moss & Tyler [2000] for further details). This interaction means that the conceptual structure account can accommodate the double dissociation between living things and artefacts, with the proviso that artefact deficits are associated with the most severe semantic impairments, while mild or moderate impairments should generally produce deficits for living things. However, as will be discussed later it is not necessarily a simple matter to compare the severity of the semantic deficit across patients.
