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Biomedical subjects

A A Hartley

Publications and source records attributed to A A Hartley.

18 recordsLinked to original sources
PubMed1992

Allocation of visual attention in younger and older adults.

Younger and older adults were compared in three experiments, using procedures that had been shown to affect the spread of visual attention. The attentional effects found in previous experiments were replicated. A broader focus of attention speeded responses to peripheral targets. In addition, two established findings concerning aging were replicated: Responses were slower in older than in younger adults, and, in certain conditions, they slowed more rapidly as target eccentricity increased. No interactions of age effects with attentional manipulations were found. The results of all three experiments were consistent with the interpretation that younger and older adults do not differ in the allocation of attention.

Adult↗
PubMed1991

Attentional and perceptual contributions to the identification of extrafoveal stimuli: adult age comparisons.

Gerontological researchers have been cautioned that conclusions about age differences in attention may have been inferred from data that, in fact, reflected age differences in perceptual processing of stimuli falling outside the fovea (Cerella, 1985). Presumably, the experimental manipulations on which Cerella based his caution induced a broad focus of attention so that changes in perceptual processing would not be confounded with changes in attention. Experiment 1 tested this by comparing a condition similar to Cerella's with another in which attention was narrowly focused at fixation. The results replicated Cerella's findings. In addition, there were greater age differences when attention had been narrowly focused, showing that attentional effects can be separated from the effects reported by Cerella. Experiment 2 showed that age differences in extrafoveal perception could be removed by increasing the duration of the target from 200 to 2000 ms, suggesting that the perceptual deficits in older adults are due to differentially lengthened processing of stimuli outside the fovea.

Adolescent↗
PubMed1990

Age differences and similarities in the effects of cues and prompts.

A series of 6 experiments investigated the use of cues and prompts by younger and older adults. Cues provide useful information about an impending target, even though the information is not always valid. Prompts provide an instruction about what aspect of the target is to be responded to. The costs and benefits of cues were most consistent with models in which the attentional resources that are shifted in response to the cue were as large or larger in older adults as they were in younger adults. The results with both cues and prompts converged on the conclusion that the time course of processing and using a cue or prompt is the same in younger and older adults. The attentional resources tapped by these procedures cannot be the diminished processing resource to which many age differences in cognitive performance are attributed.

Adolescent↗
PubMed1990

Structural equation models of relationships between exercise and cognitive abilities.

Data were obtained from 300 men and women aged 55 to 91. Separate structural equation models of relationships between physical exercise and 3 cognitive performance variables--reaction time, working memory, and reasoning--fit the data well. Other variables in the models were age, health, education, and morale. Age and exercise affected each performance variable directly; education had a direct effect on reasoning only. There were also indirect effects of age and health on performance variables, mediated through exercise. The main hypothesis of the study, that exercise contributes to performance, was supported. A large decrease in model fit resulted when the path from exercise to each performance variable was deleted. Hypotheses that age-related deficits are primarily accounted for by lack of exercise or by poor health were not supported.

Aged↗
PubMed1990

The game of bridge as an exercise in working memory and reasoning.

Fifty bridge players and 50 nonplayers, between the ages of 55 and 91, were given tests of working memory, reasoning, reaction time, and vocabulary. Data were analyzed using multivariate and univariate analyses of variance with age as a covariate. Results indicated that the players outperformed nonplayers in measures of working memory and reasoning, but not vocabulary and reaction time. Results were consistent with the hypothesis that bridge, which provides specific experience in working memory and reasoning, should enhance performance in tasks tapping these abilities and not enhance performance in unrelated abilities. Because the data were correlational, the rival hypothesis that bridge playing selects for individuals who perform better at working memory and reasoning tasks could not be rejected.

Aged↗
PubMed1989

Relationships between physical exercise and cognitive abilities in older adults.

We investigated relationships between physical exercise and the cognitive abilities of older adults. We hypothesized that the performance of vigorous exercisers would be superior to that of sedentary individuals on measures of reasoning, working memory, and reaction time. We gave a series of cognitive tasks to 62 older men and women who exercised vigorously and 62 sedentary men and women. Multivariate and univariate analyses of variance, with age and education as covariates, indicated that the performance of the exercisers was significantly better on measures of reasoning, working memory, and reaction time. Between-group differences persisted when vocabulary, on which the performance of exercisers was superior, was used as a third covariate. Subsequent analyses showed that neither self-rated health, medical conditions, nor medications contributed to the differences between exercise groups. Results suggest that the possible contribution of physical exercise to individual differences in cognition among older adults should be further investigated.

Adult↗
PubMed1987

Age differences in the speed of cognitive operations: resolution of inconsistent findings.

Gaylord and Marsh (1975) and Cerella et al. (1981) found that the speed of cognitive operations in the mental rotation paradigm was significantly slower for groups of older adults with mean ages of 68 and 73 years than for groups of younger adults. Jacewicz and Hartley (1979) found no difference between a group of adults with a mean age of 56 and a group of younger adults. The present study included a group of younger adults, a late-middle age group with a mean age of 56, as well as an older group with a mean age of 74. The results replicated both those reported by Jacewicz and Hartley (1979) and those reported by Gaylord and Marsh (1975) and Cerella et al. (1981). They are consistent with a hypothesis of generalized central nervous system slowing, but they show that the slowing does not begin to affect performance until the sixth decade of life.

Adult↗
PubMed1986

Age differences and changes in sprint swimming performances of masters athletes.

Sprint swimming speeds were compared in cohorts of masters swimmers ranging from 25-29 to 65-69 years of age in 1976. The cross-sectional comparisons were repeated for the same cohorts in 1981. The ten fastest performers in the United States in each cohort were obtained for women (n = 1407) and men (n = 1437) in 50-yd and 100-yd races for each of the four competitive strokes. Results showed the greatest decrement in performance with increasing age for the butterfly stroke. The slowing with age was unaffected by the length of the race. The results supported the hypothesis that age differences in performance are due primarily to differences in muscle strength. As in previous studies, changes in performance with age in the same cohort were substantially smaller than differences between cohorts.

Adult↗
PubMed1986

Instruction, induction, generation, and evaluation of strategies for solving search problems.

Two experiments found that older adults can execute efficient strategies for search problems when instructed in their use. They continue to use these strategies after instruction and transfer their use to similar problems. The results did not support the contention that older adults can be led to discover efficient strategies by manipulation of salient stimulus features such as color. It seemed likely that age differences in search performance were due to deficiencies in strategy production. A third experiment directly examined the generation and evaluation of strategies by younger and older adults. Age differences were localized in optimal strategies; older adults were less likely to generate or use optimal strategies and rated them as less informative than did younger adults.

Adult↗
PubMed1984

Performance changes in champion swimmers aged 30 to 84 years.

Performance changes in champion swimmers aged 30 to 84 years were examined using both longitudinal and repeated cross sectional designs. When single cross sectional slices of the data were analyzed, decrements in performance with advancing age were found, similar to those reported in older track athletes. When the same individuals or cohorts were followed over time, the changes were found to be substantially smaller. The results also showed greater age changes in short, anaerobically-swum races than in longer, aerobically-swum races.

Adult↗
PubMed1983

Meaningfulness and problem-solving performance by younger and older adults.

Younger and older adults solved reasoning problems in either abstract or meaningful form. Contrary to expectation, older adults did not differ on the two versions, but younger adults were aided by meaningfulness. Results of a second task showed no age differences in the time to produce associations to problem elements or in the number of associations. There were differences in the quality of associations, and association quality was significantly related to performance on the reasoning problems for older adults.

Adolescent↗
PubMed1983

Task complexity and problem-solving performance in younger and older adults.

In problems resembling the Twenty Questions game, older and younger adults were asked to discover the square or squares the experimenter had in mind from an array of squares. Complexity was varied in three conditions in which problems had 6, 8, or 12 bits of information. Task demands were increased in a fourth condition by imposing a 60-sec time limit. Contrary to a hypothesis drawn from prior results, no evidence was found that older adults select more efficient strategies as task complexity or demands increase. Both age groups maintained the same strategies; the less efficient strategies selected by the older persons were reduced in effectiveness as task complexity increased.

Adolescent↗
PubMed1983

Task complexity, problem representation, and problem-solving performance by younger and older adults.

To test the hypothesis that increased task difficulty elicits more efficient problem-solving strategies from older adults, younger and older persons were given Twenty Questions tasks with either 64 or 10,000 possible solutions and with the possible solutions either physically present or not. Although younger adults were more efficient than older adults, there was no evidence that task difficulty affected problem solving for either age group.

Adult↗
PubMed1981

Mental measurement of line length: the role of the standard.

Reaction times were examined for magnitude estimates of line length. In the first two experiments, reaction times increased linearly with judged length. This result is consistent with the hypothesis the judgments are made by laying off a mental image of the standard along the line to be judged. The slope of the function relating judged length to reaction time was not affected by the length of the standard line, suggesting that the rate at which the image of the standard is laid off is not a function of the length of the standard. Reaction time also increased linearly with judged length when subjects judged line length when the standard of 1 in. was suggested but not provided as well as when no standard was suggested. The hypothesized laying-off process was compared to other cognitive manipulations, such as mental rotation and size scaling. Equivalence of judgments based on the representation of the standard in perceptual memory and in imagination is discussed.

Discrimination Learning↗
PubMed1981

Adult age differences in deductive reasoning processes.

To explore deductive inference processes on concept learning a problem was given to individuals from four groups: younger adults (mean age 20.0 years), middle-aged adults (41.4 years), and two groups of older adults (65.4 and 71.5 years). The first three groups were college students or college graduates; the last group was drawn from the local community. Likelihood of solution was lower in the older groups; the two older groups did not differ, not did the younger and middle-aged groups. Analyses of hypotheses generated during the task showed that those who failed to solve the problem, whatever their age, overlooked evidence that a dimension as relevant (but only when attention had not been drawn previously to that dimension) and failed to respond appropriately when a dimension was shown to be irrelevant.

Adolescent↗
PubMed1979

Rotation of mental images by young and old college students: the effects of familiarity.

Younger and older college students judged whether letters, rotated from 0 to 180 degrees away from normal, upright position, were standard letters or mirror-images of standard letters. The analysis separated basic speed of response from the rate at which mental manipulations of the images of the letters took place. With letters from the English alphabet, younger (mean age, 21.6 years) and older (mean age 55.9 years) sugjects did not differ either in basic speed or in rate of manipulation. With unfamiliar, lower-case Greek letters, however, the basic speed of older subjects (mean age, 56.5 years) was slower than that of younger subjects (mean age, 21.2 years) while there was no difference in rate of manipulation. The results are inconsistent with an hypothesis of general slowing of central nervous system activity.

Adolescent↗