A domain-specific deficit for foodstuffs in patients with Alzheimer's disease.

Although some studies have reported a category specific naming deficit in Alzheimer’s patients (invariably for living things), others have failed to replicate this finding (Laws et al., in press). Inconsistencies may partly stem from the fact that category effects are hidden in group analyses because individual Alzheimer’s patients show category deficits in opposing directions, namely, some living and some nonliving (Gonnerman et al., 1997). Additionally, category effects may depend upon the specific composition of living things, such as the ratio of animals to fruits and vegetables, though this has never been explicitly examined. To examine this, we conducted a more detailed fractionation of living and nonliving categories for individual patients.