Letter matching: effects of age, Alzheimer's disease, and major depression.
We compared Alzheimer's disease (AD) patients and Major Depressive Disorder (MDD), Aged normal, and Young normal controls on a letter-matching task designed to measure the time needed to access overlearned linguistic information in long-term memory. Name identity (NI) and physical identity (PI) reaction time and the NI-PI difference were compared for ADs, MDDs, and Aged normals and separately for Aged and Young normal groups. AD subjects had slower NI and PI reaction times and a bigger NI-PI difference than Aged normal and MDD subjects, suggesting that speed of access to overlearned letter-name information in long-term memory is slowed for ADs. There were no reliable differences between Aged normal and MDD subjects. Aged normals had slower NI and PI reaction times and a bigger NI-PI difference than Young normals, suggesting that the highly practiced operations needed to access letter-name information slow with age. A discriminant analysis was used to evaluate the usefulness of the "easy to perform" letter-matching task for diagnostic purposes. Ninety percent of normal and MDD subjects but only 68% of AD subjects were classified correctly.
Kerr
B
B
Department of Psychology, University of Washington, Seattle 98195.
Calogero
M
M
Vitiello
M V
MV
Prinz
P N
PN
Williams
D E
DE
Wilkie
F
F
D000328:Adult; D000368:Aged; D000375:Aging / Q000523:psychology*; D000544:Alzheimer Disease / Q000523:psychology*; D003071:Cognition / Q000502:physiology; D003866:Depressive Disorder / Q000523:psychology*; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time