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Biomedical subjects

A Kjellberg

Publications and source records attributed to A Kjellberg.

13 recordsLinked to original sources
PubMed1992

Sustained attention and serial responding in heat: mental effort in the control of performance.

The effects of heat (40 degrees C) on sustained attention and serial responding were studied in a simple reaction time task and a serial four choice reaction time task, respectively. Core temperature (Tc), heart rate variability (HV) and subjective reactions were monitored during the 80 min of exposure time. Simple reaction time performance and accuracy in the serial choice reaction time task deteriorated significantly in heat. In the serial choice reaction time task, the effects of heat on response times and on HV were correlated. Performance and level of Tc were not correlated, but a relationship was found between performance and rate of Tc change. Results are discussed in relation to the thermophysiological status of the subjects and the compensatory mechanism of effort allocation. It is proposed that task characteristics regulate the degree of activity of this compensatory mechanism.

Adult↗
PubMed1991

Noise annoyance during the performance of different nonauditory tasks.

Three experiments were performed to study the effects of an ongoing task on the annoyance response to noise. In the first two experiments a total of five tasks were used: three versions of a proofreading task, a finger-dexterity task, and a complex reaction time (RT) task. Subjects performed the tasks during exposure to two levels of a continuous broadband noise. Task was of no consequence for rated annoyance. Four tasks were used in Experiment 3: proofreading, complex RT, grammatical reasoning, and simple RT. A third type of noise, irrelevant speech, was added to the broadband noises. Rated annoyance was lower during simple RT than during the reasoning and proofreading tasks, especially in the irrelevant speech condition. The difference corresponded to a 6-dB difference in noise level. It was concluded that task differences probably only explain a small part of the widely differing noise tolerance levels at different work places.

Adult↗
PubMed1990

Behavioral and psychophysiological effects of the physical work environment. Research strategies and measurement methods.

An international course on the behavioral and psychophysiological effects of the physical work environment was held in Stockholm, Sweden, in April 1988 by the Nordic Institute of Advanced Training in Occupational Health and the Swedish National Institute of Occupational Health. It dealt primarily with the behavioral and psychophysiological responses to aspects of the physical work environment and was devoted to neural and behavioral functions. The increasing interest in these functions is mainly motivated by the involvement of the central nervous system in the adverse effects induced by unfavorable environmental conditions of the workplace and by the need for more sensitive indicators than those based solely on recognized occupational disease and pathology. By describing the main aspects of the research strategies and the measurement methods used in this field of research, this paper provides a background for the assessment and evaluation of the early behavioral and psychophysiological indices of potential occupational hazards.

Affect↗
PubMed1990

Psychological aspects of occupational vibration.

A short review is given of the subjective responses to vibration (primarily whole-body vibration) and of its performance and psychophysiological effects. The subjective importance of the basic physical vibration parameters and the effects of whole-body vibration on performance of tasks requiring manual control and visual acuity have been well covered by research, whereas knowledge of the effects on cognitive performance is rather meager.

Biomechanical Phenomena↗
PubMed1990

Subjective, behavioral and psychophysiological effects of noise.

The subjective and psychophysiological responses to noise and the effects of noise on performance have been reviewed in this article. Emphasis was placed on moderate-intensity noise and on the effects relevant for occupational noise exposure. It was concluded that in many respects research presents a rather inconsistent picture of these effects. Still, it is evident that the nonauditory effects of noise may be serious enough to warrant as much general attention in the occupational setting as has for some time been accorded in residential settings.

Attention↗
PubMed1987

Acute effects of whole-body vibration. Stabilography and electrogastrography.

The influence of whole-body vibration on postural control and stomach motility was investigated. Fifteen subjects were exposed to two vibration signals (3 and 6 Hz random) while sitting for 1 h on a vibration simulator. A control situation, ie, sitting for 1 h without vibration, was also included. Stabilographic recordings before and 1 and 15 min after the sitting showed that exposure to these frequencies had no effect on postural control. Electrogastrographic (EGG) measurements before and during the sitting showed that, for 3 Hz, there was an initial increase in activity which decreased towards normal values. For 6 Hz there was a significant increase in activity for EGG frequencies of 0.05 and 0.13 Hz. The results imply that stomach motility can be affected by whole-body vibration in certain frequency ranges.

Adult↗
PubMed1979

Physiological response patterns during "intake" and "rejection" tasks.

Two 2-min tasks, one requiring outer-directed attention (intake task), the other a mental arithmetic task (rejection task) were presented to 20 subjects. According to Lacey the distinguishing feature of the response to intake tasks are cardiac deceleration and blood pressure decreases. None of these responses was obtained. Some variables, however, were only affected by one of the tasks; the intake task led to a decreased hand (skin) blood flow and an increased hand vascular resistance, whereas a heart rate acceleration and increased forearm (muscle) blood flow and decreased forearm vascular resistance were observed during the rejection task. Blood pressure, respiration rate and skin conductance were similarly affected by the two tasks. Inconsistencies among previous studies of the response to the two types of tasks were discussed and found to be partially explained by methodological differences.

Adult↗