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Biomedical subjects

J Botwinick

Publications and source records attributed to J Botwinick.

8 recordsLinked to original sources
PubMed1979

Stimulus persistence and age.

Stimulus persistence theory states that the effects of stimulation are longer lasting in the nervous system of the old person than the younger one. This concept and its relation to perceptual functioning and age was examined via two perceptual aftereffect tasks, the Spiral and the Waterfall. Twenty-four elderly adults (mean age = 65.5) and twenty-four young adults (mean age = 24.8) were each exposed to both stimulus displays, at four exposure durations: 45, 60, 90, and 120 seconds. Following the offset of each display, the duration of any apparent motion aftereffect was recorded. Although on the basis of stimulus persistence theory it was expected that the elderly would exhibit longer mean aftereffects than the young, no support for this hypothesis was noted. Possible explanations of these results and their relation to previous findings, in terms of fatigue effects and sample characteristics, are discussed.

Adult↗
PubMed1979

A long-term longitudinal study of intellectual ability of older adults: the matter of selective subject attrition.

Two hundred and forty-six subjects aged 60 to 94 were tested with the WAIS at test session 1, the start of a longitudinal study which lasted approximately 20 years. The subject attrition from the first session to the last (session No. 11) was progressive and selective, leaving mainly the intellectually superior ones in the study. Two facts appeared particularly important: One, little intellectual decline was seen in these superior subjects until very late in life. Two, analyses based on such superior subjects without reference to the larger body of subject populations can lead to spurious generalizations about aging in general. Age decline in intellectual ability seen in more representative populations may not be apparent when analyzing data of select samples.

Aged↗
PubMed1979

Age differences in resolving power and decision strategies in a weight discrimination task.

Current theories of aging suggest that at least part of the decline in performance on psychophysical tasks, commonly observed in older subjects, may be the result of their becoming more cautious about sensory decisions. This conclusion has been supported by experiments in which the criterion index, beta, from signal detection theory is shown to be higher (indicating a strict criterion) for older subjects. A weight-discrimination experiments is reported which failed to replicate the earlier results; older subjects' criteria were the same or more lax than those of younger controls on that task. The possibility that extreme caution on the part of older people may be specific to certain classes of task is discussed.

Adult↗
PubMed1978

Predicting death from behavioral test performance.

This study described several brief behavioral measures which, with further validation, could be useful in predicting the deaths of older adults within a five-year period following testing. Such tests can be used in routine biomedical examinations, alerting the physician to possible problems in the future. The study was based on a battery of 18 tasks as well as 8 measures of health, social activity, and demographic characteristics administered to 380 healthy men and women aged 60 to 89 years. Five years later, the scores of those who had subsequently died (N = 83) were compared with a matched sample of those still living. Thirteen of the 18 task performances significantly distinguished between those still living and those who died. Discriminative analyses were carried out, and the discriminative score cut-offs correctly classified 66% of the subjects as to survival status.

Affective Symptoms↗
PubMed1976

Disparate time spans in sequential studies of aging.

In several published studies of intelligence and adult age, a sequential design was used in which birth cohort and time of measurement were the independent variables in an ANOVA. The time span of these two variables were quite disparate; the cohort variable covered about 50 years whereas the time-of-measurement variable covered 7 or 14 years. It was demonstrated here that when time spans are disparate, even when all differences are attributable entirely to age changes, the F values typically will be larger for the cohort variable and errors in interpretations became likely. When cohort differences are statistically significant and time-of-measurement differences are not, the conclusion that age differences are "generational" and not due to age changes within individuals may be wrong.

Adult↗
PubMed1975

Predictors of a dimension of well-being in the relocated healthy aged.

One hundred twenty-two subjects aged 61 to 88 years were given a wide variety of tests around the time they moved to an apartment complex in which independent living and self-care was necessary. After living in their apartments approximately 15 mo., they were rated for how well they were faring in terms of a clinical dimension, from "played out" to "vital." Of 25 predictor variables, 14 were related to this dimension. Two were especially prominent--the WAIS Comprehension subtest and the Crossing-Off psychomotor task.

Adaptation, Psychological↗
PubMed1975

Qualitative vocabulary test responses and age.

Vocabulary test responses, as traditionally scored were compared to these same responses when scored for finer nuances of understanding, as determined by the criterion of superior synonyms. It was hypothesized that the latter would be more related to age in a deficit pattern than the former. The results partly supported the hypothesis and partly not. In the context of the positive results, it is not clear whether the aged cannot, or simply do not, give synonym responses as readily as the young. It may be more of a cohort preference not to, rather than an age limitation of intellectual ability.

Adult↗