The ability to generate words from phonemic (i.e.,
words beginning with ‘F,’ ‘A,’
and ‘S’) and semantic (i.e., animals, fruits,
and vegetables) categories was assessed longitudinally
in patients with Alzheimer's disease (AD; N
= 59) and normal controls (NC; N = 59). Patients
with AD performed worse than NC participants on both tasks
at each of 4 annual evaluations and exhibited greater impairment
relative to controls on the semantic-category task than
on the phonemic-category task. In addition, the performance
of the patients with AD declined over time on both tasks,
but the rate of decline was faster on the semantic-category
than on the phonemic-category task. Examination of individual
responses across the annual evaluations revealed that patients
with AD were more consistent than NC participants in failing
to generate previously produced semantic-category, but
not phonemic-category, items in all years following the
1st year in which the item was not produced. These results
are consistent with the notion that patients with AD suffer
a gradual deterioration of the organization and content
of semantic memory as the disease progresses. (JINS,
1999, 5, 692–703.)