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.