Neuropathological diagnosis of Alzheimer disease.
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Alzheimer Disease↗
Biomedical subjects
W Zigman
Publications and source records attributed to W Zigman.
Alzheimer-type neuropathology and clinical symptoms of dementia in mentally retarded people without Down syndrome.
Postmortem morphometric analyses of Bielschowsky stained sections from brains of 70 mentally retarded people without Down syndrome, age 65 and over when they died, indicated Alzheimer-type neuropathology in 22 cases (31%) and a majority with at least presence of some Alzheimer-type lesions. Based upon information abstracted from clinical histories, however, old-age-associated dementia proved to be difficult to judge reliably. Nevertheless, for otherwise healthy individuals (n = 25), loss of motor skills, development of problem behaviors, and a 10-point drop in IQ appeared to be likely indicators of Alzheimer's disease. Prevalence estimates of Alzheimer-type neuropathology among nonretarded people and the present sample appear comparable, and projections must be made to address the special needs of this rapidly growing population of retarded people.
Aged↗
Extended recency effect extended: blocking, presentation mode, and retention interval.
The effect of blocking of stimulus items on the free recall of EMR adolescents was examined. In Experiment 1 a multitrial free-recall list of 15 pictures was presented either simultaneously in groups of 3, or sequentially, one at a time. Consistent ordering was used in both conditions, so that on each trial, each item in each set of 3 pictures was presented contiguously with the other 2 items from that set. In addition, recall came immediately or after a filled or unfilled delay of 24.5 seconds. Results showed that simultaneous presentation led to higher recall, subjective organization, and clustering than did sequential presentation, but analysis of serial-position curves showed a much reduced extended recency effect in comparison with previous studies. Experiment 2 was designed to determine whether the cause of the reduced extended recency was the use of pictures rather than words as stimuli. Stimuli were presented either as pictures, as pictures with auditory labels, or as words with auditory labels, with both simultaneous and consistent ordering for all conditions. Results indicated a strong extended recency effect for all groups, eliminating presentation mode as a causal factor in the data of Experiment 1. We concluded that blocking leads to increased organization and recall over a variety of presentation modes, rates, and block sizes.
Adolescent↗