CATEGORIES OF KNOWLEDGE - UNFAMILIAR ASPECTS OF LIVING AND NONLIVING THINGS

This paper reports an investigation into an apparent category-specific disorder in a young woman whose semantic memory was impaired following a road accident. In Experiment 1, an impairment for processing specific items in tasks of naming pictures and defining words was related to a selective impairment for living things and also to the familiarity level of the items. In Experiment 2, a difference in semantic category (living or nonliving) was pitted against a difference in familiarity (high or low) in a picture-naming task. A significant effect of familiarity was found, but no effect of semantic category. It was shown that, in a widely used set of published pictures, living things were generally of lower familiarity than nonliving things. Moreover, measures of familiarity were shown to be confounded with some reported evidence in support of a selective impairment to living things. It was concluded that, at present, there is no convincing evidence to support the theory that semantic memory is organised into dissociable categories of living and nonliving things.