title: Letter matching: effects of age, Alzheimer's disease, and major depression.
abstract: 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.
authors.affiliation: Department of Psychology, University of Washington, Seattle 98195.
authors.forename: B
authors.initials: B
authors.lastname: Kerr
authors.forename: M
authors.initials: M
authors.lastname: Calogero
authors.forename: M V
authors.initials: MV
authors.lastname: Vitiello
authors.forename: P N
authors.initials: PN
authors.lastname: Prinz
authors.forename: D E
authors.initials: DE
authors.lastname: Williams
authors.forename: F
authors.initials: F
authors.lastname: Wilkie
mesh_terms: 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