ABSTRACT
In many studies in which category-specific deficits were reported, the stimuli were taken from Snodgrass and Vanderwart’s (1980) collection of object drawings. Snodgrass and Vanderwart (1980) have supplied norms for name agreement, image agreement, familiarity, and visual complexity for their picture set, so it is relatively straightforward to determine whether the living and non-living objects used in studies that report category-specific deficits differed on these variables, or to design studies in which these variables are controlled. Interestingly, when familiarity, word frequency and name agreement were matched for living and non-living stimuli, Funnell and Sheridan (1992) found that a disproportionate impairment for living things disappeared in one patient. Gaffan and Heywood (1993) and Stewart, Parkin, and Hunkin (1992) also found that the poorer performance for living things compared to non-living things observed in their patient disappeared once word frequency, familiarity and visual complexity were matched for the two categories. However, Farah, Meyer, and McMullen (1996) found that when two of their patients were tested on exactly the same set of pictures but with further replications, their selective deficits for living things remained. Gainotti and Silveri (1996) and Kurbat (1997) also found that category-specific effects occurred in their patients when the normed variables were controlled. Together, these results indicate that category-specific effects are not purely due to any differences in familiarity, word frequency, and name agreement that might exist between the categories of living and non-living things.
