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PubMed1991

Serial-position effects in paragraph recall following mild closed-head injury.

Serial-position effects were examined on a contextual memory task (paragraph recall) for patients with minor to mild closed-head injury and normal controls. Analysis indicated that at immediate recall, both normals and closed-head-injury patients have primacy and recency effects. With regard to total recall, however, the closed-head-injury patients remembered significantly fewer items than normal controls. The poorer performance of the minor to mild closed-head-injury group was not related to the duration from injury to neuropsychological evaluation and appears to be a lasting feature of memory performance following such injury. The pattern of serial-position effects was different between the groups. Normal controls showed slight recency and primacy effects and relatively better recall for the middle portions of the story, while patients with minor to mild closed-head injuries have prominent recency and primacy effects. Potential explanations for this pattern of performance are discussed.

Adult↗
PubMed1991

Effects of a three-year exercise program on motor function and cognitive processing speed in older women.

This study evaluated the effects of a three-year exercise program on motor performance and cognitive processing speed of previously sedentary older women, ages 57-85. Variables tested were simple and choice reaction time (CRT), balance, sit and reach flexibility, shoulder flexibility, and grip strength. Subjects participated three times a week in exercise performance classes designed to meet American College of Sports Medicine guidelines. Results indicate that performance was significantly improved on all measures during the course of the study (p less than .01) except for the sit and reach test (SRT), where significance was approached (p less than .027), but not reached. A comparison of the exercise subjects with a comparable group of nonexercising control subjects revealed significant interactions between treatment and time on all variables except CRT and grip strength. Pretest to posttest scores of the exercise subjects tended to improve over the three-year period, whereas the scores of the control subjects declined. Improved reaction time indicated exercise is effective in reversing or at least slowing ceratin age-related declines in motor performance and in speed of cognitive processing.

Aged↗
PubMed1989

Measuring effectiveness in health visiting.

While resources for health remain limited, all managers must be able to demonstrate the cost-effectiveness of the services provided. Computer technology now provides the data with which to measure efficiency. Health visitors (together with other community-based professions) need to recognise the opportunities that information technology (IT) offers to help improve the planning and management of services. This article outlines the use of information to understand better the present delivery of health visitor services, to set objectives for the future and to measure actual performance against intended; in the near future to match better the supply of services to demand by developing neighbourhood or GP-practice profiles using mapping and graphics techniques; and in the longer term to refine measures of need or 'dependency' and 'outcome' to target resources and improve effectiveness.

Community Health Nursing↗
PubMed1991

Acute reduction in maximal oxygen uptake after long-distance running.

Nine male marathon runners, 24 to 39 years of age, were studied during steady state and maximal graded treadmill exercise under control conditions (C) and immediately after a paced outdoor 21.1-km run averaging 89.5 min (E). The half-marathon run and both treadmill trials were performed at 239 +/- 33 m/min. Oxygen uptake (VO2), respiratory exchange ratio (RER), heart rate (HR), plasma lactate concentration (PLa), and rating of perceived exertion (RPE) were measured in the steady state at 0% grade and at the fatigue end point. Compared to C, mean values in E were significantly lower (p less than 0.05) for time to exhaustion (6.0 vs 4.1 min), VO2max (60.0 vs 56.3 ml/kg/min), peak RER (1.18 vs 1.06), and PLa (9.7 vs 7.8 mM/L), whereas maximal HR (184 vs 184 b/min) and peak RPE (19.6 vs 19.9) were not significantly different between trials. Submaximal VO2 during steady-state runs was similar between C and E (44.4 vs 45.0 ml/kg/min; p = NS). Since the attainable VO2max decreased after E, the percentage of VO2max utilized during steady-state runs was higher, averaging 74% in C and 80% in E (p less than 0.05). In the steady state during E, HR (153 vs 161 b/min) and RPE (13.2 vs 14.8) were higher (p less than 0.05), and the increase in PLa from rest (2.7 vs 1.9 mM/L) was lower (p less than 0.05). Submaximal HR during graded exercise in E was 7 to 8 b/min higher (p less than 0.05) at a given VO2, indicating reduced heart rate reserve.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Divided attention and metabolic brain dysfunction in mild dementia of the Alzheimer's type.

The relationship between reaction time (RT) measures under single-task and dual-task conditions and resting levels of brain metabolism, as measured by positron emission tomography (PET), was examined in patients with mild dementia of the Alzheimer type (DAT) and age- and educationally-matched controls. Slowing of RT in dual-task but not single-task conditions correlated with reductions in brain metabolism in right premotor and right parietal association areas only for the mild DAT patients. The results suggest a relation between divided attention deficits and metabolic dysfunction of right frontal and parietal lobes in mild DAT patients.

Aged↗
PubMed1976

Misuse of analysis of covariance in aging research revisited.

Storandt and Hudson's treatment of the issue of which general linear model technique is preferable to use when age effects are confounded is misleading. Contrary to their position that hierarchical ANOVA or step-wise multiple regression is superior to ANCOVA, it is demonstrated, using hypothetical data, that identical amounts of variance can be explained by ANCOVA relative to hierarchical ANOVA and multiple regression. Multiple regression is recommended as the most appropriate technique for a variety of pragmatic reasons concerning calculation of significance tests, the distinction between gross and net effects, and the choice of the metric used in measurement.

Adult↗
PubMed1975

Some effects of ACTH 4-10 on performance during a serial reaction task.

Eighteen subjects worked continuously for half an hour in a self-paced reaction task. Half of the subjects were injected with ACTH 4-10 (30 mg/s.c.) and the other half with a placebo. The subjects injected with ACTH 4-10 showed a larger improvement in reaction time during the experimental session than the placebo group. However, this effect disappeared in a short retest, which was given half an hour after the experimental session. These results suggest that ACTH 4-10 has no effect on skill acquisition, but counteracts the build-up of reactive inhibition during the experimental session; that is, the peptide suppresses the decrease in motivation, which usually occurs during continuous performance tasks. This notion is confirmed by an analysis of the frequency distributions of the reaction times. Treatment effects were only found for the long reaction times. Long reaction times tend to occur with increasing frequency as a function of time-on-task and are an indication for the level of motivation of the subject. It was concluded that ACTH 4-10 counteracts the usual decay in performance as a function of time-on-task due to increasing boredom and mental fatigue.

Adrenocorticotropic Hormone↗
PubMed1988

Instrument flight performance under the influence of certain combinations of antiemetic drugs.

Two different combinations of antiemetic drugs were evaluated using a digital flight simulator. Drug treatments consisted of a lactose placebo, a combination of thiethylperazine (10 mg) and cimetidine (300 mg), and a combination which added promethazine (25 mg) to the two-drug combination. The performance effects of these combinations were evaluated on both a dual task (instrument flight task with the Sternberg Memory Scanning task) and a single task condition (Sternberg task only) for 3 h post drug ingestion. Analysis indicated a significant treatment effect on three of the six flight performance variables and that the three-drug combination, containing promethazine, was primarily responsible for the decrease in performance. Implications for operation in a radiation environment are that thiethylperazine and cimetidine will not cause significant performance decrements, but the addition of promethazine to those two drugs will significantly impair performance. The Sternberg task was sensitive to changes in workload.

Adult↗
PubMed1992

Characterization of the physical demands of firefighting.

To characterize the physical demands associated with on-the-job use of current firefighting equipment and the performance of essential firefighting operations, an initial task analysis of all firefighting operations was followed by an in-depth physical and physiological characterization of those tasks deemed to be physically demanding. The most commonly encountered applications of strength and endurance were lifting and carrying objects (up to 80 lbs), pulling objects (up to 135 lbs), and working with objects in front of the body (up to 125 lbs). The most demanding firefighting operations required a mean VO2 of 41.5 ml/kg.min-1 with peak lactate concentrations of 6 to 13.2 mM. Ninety percent of the demanding firefighting operations that were studied required a mean VO2 of 23 ml/kg.min-1. These aerobic energy requirements corresponded to 85 and 50% VO2max, respectively. Therefore a minimum VO2max standard for firefighter applicants of 45 ml/kg.min-1 is recommended.

Adult↗
PubMed1976

Laboratory investigation of "biorhythms".

Three subjects were tested on an information processing task on a daily basis for a period of 70 d. Performance measurement included reaction time, movement time, and information processing rate. The data set obtained was subjected to Fast Fourier Transforms (FFT) in an attempt to identify periodicities in performance. Twelve significant harmonics were identified and nine were found to be within 1 d of at least one of the cycles hypothesized by the theory of "biorhythms." The probability of this occurring by chance is remote (p less than 0.05), assuming a uniform distribution of significant amplitude. The results were interpreted as suggesting the possibility of a biorhythmic influence in the performance of the task.

Adult↗