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Biomedical subjects

P A Hancock

Publications and source records attributed to P A Hancock.

8 recordsLinked to original sources
PubMed1990

Driver workload during differing driving maneuvers.

Motorcycle-automobile accidents occur predominantly when the car driver turns left across the motorcyclist's right-of-way. Efforts to decrease this specific collision configuration, through an increase in motorcycle conspicuity, have concentrated on the physical characteristics of the motorcycle and its rider. The work reported here examines the behavior of car drivers during different driving sequences, in particular during left-turn maneuvers. An experiment is reported that used simultaneous video-taping of the driver and the forward-looking scene. Subjects followed a preset on-road course and were observed for head movements to determine the possibility of structural interference eye-blink frequency, probe-response time, and probe response error, as measures of cognitive or mental workload. In addition, the subjects completed two major subjective workload evaluations as reflections of effort directed to different components of the driving task. Results indicated that there were significant increases in head movements and mental workload during turn sequences compared to straight driving. This result of higher driver workload may be responsible for increasing the potential for detection failure. Such a propensity is also fostered by the higher structural interference that may be expected during turns. Failures to observe during turning sequences have differing outcomes depending on the presence of opposing traffic, as during the left turn, compared with the absence of such opposition, as occurs in the right turn. Also, the less conspicuous the oncoming vehicle in the left turn scenario, the higher the probability of detection failure. At the present time the least conspicuous powered vehicle is the motorcycle.

Accidents, Traffic↗
PubMed1989

A dynamic model of stress and sustained attention.

This paper examines the effects of stress on sustained attention. With recognition of the task itself as the major source of cognitive stress, a dynamic model is presented that addresses the effects of stress on vigilance and, potentially, a wide variety of attention-demanding performance tasks.

Adaptation, Physiological↗
PubMed1989

Time estimation performance before, during, and following physical activity.

An experiment is reported which evaluated performance on a 10-sec unfilled time interval estimation task before, during, and after physical work on a cycle ergometer at relative intensities of 30 and 60% VO2max. Results from eleven healthy male subjects revealed a significant increase in time estimation variability and a decrease in the mean estimated time intervals during exercise compared to non-exercise phases. These findings are part of a growing body of evidence which indicates that exercise and its severity has a substantive impact on perceptual and cognitive performance, particularly the ability to synchronize and anticipate the timing of events.

Adult↗
PubMed1986

The effect of skill on performance under an environmental stressor.

This paper examines the effect of individual skill level upon task performance in transient extreme heat. A summary of published data suggests that individuals who are skillful at the task are better able to withstand the detrimental effect of the stress exposure than their unskilled counterparts. Three theoretical explanations of such performance superiority are reviewed: behavioral arousal; attentional capacity; and automatic and controlled processing. It is concluded that the automatic and controlled information processing approach holds the greatest potential to account for this effect at the present time. It is suggested that the ability of skilled subjects who are able to resist the effect of heat stress may be a more general attribute of personnel who operate under a variety of non-optimal environmental conditions.

Arousal↗
PubMed1985

Combined effects of heat and noise on human performance: a review.

This paper examines the combined effects of heat and noise upon behavioral measures of human performance. Specifically, capabilities on a variety of neuromuscular and mental tasks are reviewed with respect to their vulnerability to joint thermal and acoustic action. The majority of evidence indicates that such stressors do not interact significantly within the ranges experienced commonly in the industrial setting. However, various experimental and methodological inadequacies in the meager data base caution at the present time against a simple interpretation of this apparent insensitivity.

Achievement↗
PubMed1985

Physiological reflections of mental workload.

Studies reporting physiological responses as reflections of mental workload are reviewed briefly. The differing measures are located in a two-dimensional space whose axes represent first, practical application and second, relevance to actual central nervous system activity as viewed from spatial and systemic congruence. Traditional methods such as those using heart rate are identified as the most practical current measures, while evoked cortical potentials emerge as superior upon the latter axis. The potential of auditory canal temperature as an optimal composite measure is explored.

Aerospace Medicine↗