Letter matching: effects of age, Alzheimer's disease, and major depression

• Published in: Journal of clinical and experimental neuropsychology Vol. 14; no. 4; p. 478
• Main Authors: Kerr, B, Calogero, M, Vitiello, M V, Prinz, P N, Williams, D E, Wilkie, F
• Format: Journal Article
• Language: English
• Published: England 01-07-1992
• Subjects: Adult; Aged; Aging - psychology; Alzheimer Disease - psychology; Cognition - physiology; Depressive Disorder - psychology; Female; Humans; Intelligence Tests; Male; Psychiatric Status Rating Scales; Psychomotor Performance - physiology; Reaction Time
• ISSN: 1380-3395
• DOI: 10.1080/01688639208402839

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.