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Biomedical subjects

G Salvendy

Publications and source records attributed to G Salvendy.

At least 19 recordsLinked to original sources

Effects of respirators on performance of physical, psychomotor and cognitive tasks.

Possible work decrements caused by respirator usage were examined. A battery of physical, psychomotor and cognitive tasks was used to investigate the effects of respirator wear on 12 subjects. A repeated measures experimental design was used to study the effects of three types of respirators: a disposable dust mask; an air purifying half-mask; and a full-face airline mask. Performance while wearing a mask was compared to the control condition without a respirator. The results from the physical work task of riding a bicycle ergometer indicated approximately a 10% increase in oxygen consumption when subjects wore half and full-face masks in comparison to when they performed the tasks without a mask. The results indicate that wearing the respirators did not have a significant effect on the performance of cognitive tasks but did affect significantly the performance of psychomotor tasks such as steadiness of work performance and movements requiring accurate control for positioning of objects.

Adult

Microbreak length, performance, and stress in a data entry task.

The effects of brief rest pauses on performance and well-being were evaluated for a highly repetitive, data entry task. Experienced data entry operators (N = 20) performed the task in a two-day experiment in a simulated office environment. Each day was divided into six, 40-min work periods. Subjects took a brief rest pause at the workstation (microbreak) in the middle of each work period. Subjects were instructed to terminate this microbreak when ready to resume work. Keystroke rate, error rate, correction rate, heart rate and heart rate variability were scored for each half of the work period. In addition, mood states before and during the work period were assessed. Microbreaks were found to average 27.4 s in duration. High ratings of fatigue and boredom during the work period were associated with longer microbreaks, suggesting that the break period was self-adjusted relative to mood state. In addition, correction rate and heart rate were lower following long microbreaks, implying that the degree of recovery was linked to the length of the microbreak. Comparison of keystroke output and correction rate before and after the microbreak, however, revealed that performance worsened after the microbreak, suggesting that subjects terminated microbreaks before complete recovery could occur.

Adolescent

Discriminating the structure of rotated three-dimensional figures.

Visualizing the structure of transformed (by rotation) three-dimensional (3-D) figures is an important aspect of information processing for computer-graphics tasks. However, little research exists to establish the speed and accuracy in which subjects perform discrimination tasks for transformed images and the effects of rotation variables on perceiving transformed images. This research tests the effects of figural complexity, angles and axes of rotation on the speed and accuracy in which subjects discriminate the structure of rotated 3-D wireframe images. Results show that response times are affected more by angles than axes of rotation, the specific form of the image affects error rates, and the number of 90 degrees bends which determine the structure of an image may be an inadequate measure of form complexity for the task described here.

Cues

Effects of personality, perceptual difficulty and pacing of a task on productivity, job satisfaction, and physiological stress.

The relative psychological, physiological, and performance advantages and disadvantages of utilizing machine-paced and self-paced work were examined by having 12 subjects perform a marking-stapling task at 2 levels of perceptual difficulty and under 2 pacing conditions for 30 min. each. (a) 3 subjects who on the personality tests were identified as introverted, reserved, and trusting preferred to work in the machine-paced condition, while 9 subjects who were identified as extroverted, outgoing and suspicious preferred the self-paced condition, (b) the performance errors in machine-paced operation were 372% higher than for self-paced work, and (c) there were no differences between machine-paced and self-paced work on physiological variables, except for sinus arrhythmia for the task with high perceptual load, and quantity of production.

Achievement

Improving evaluation of amalgam restorations.

A predictive model of overall quality of performance is presented which might assist both dental students and dental faculty by increasing the reliability of clinical and laboratory evaluations. Training effectiveness can be improved by identification of those restorative skills which contribute most to the quality rating of restoration.

Dental Amalgam

Perceptual and motor training for the acquisition and retention of psychomotor skills in dental amalgam restorations: class I in the mandibular first molar.

From a study of 72 dental students during amalgam restoration using four training methods (psychomotor, mental, psychomotor and mental, and conventional)--one method for each 18 students--the following conclusions are drawn: (1) It is economically feasible to develop and utilize self-paced instructions without the aid of instructors for the acquisition of psychomotor skills. (2) Training through self-paced analytical programs results in higher retention of the acquired skills than training through conventional training methods.

Dental Amalgam

Skills analysis of a class I amalgam restoration in a mandibular right first molar.

1. Students changed their body position 32% more often than instructors during amalgam condensation. 2. Experienced instructors used 38% fewer strokes than students to condense the amalgam. 3. On the average, instructors used 65% less time per condensation stroke than students. This was not due to ability to move the instrument more quickly, since both students and instructors had similar minimum stroke times, but rather to the fact that instructors performed slowly less often. 4. The upstroke during condensation required nearly the same time for both students and instructors (an eight percent difference). It was the downstroke that was greatly different (a 96% difference). 5. Instructors repeated condensation strokes 22% more often than students, working more systematically with less "jumping around" in the cavity. 6. The total number of carving strokes was not related to experience. 7. Students repeated carving strokes more often than instructors. 8. Students and instructors tended to use the same length of strokes in carving. 9. There was a noticeable difference between instructors and students in the method used to grasp the instruments.

Dental Amalgam

Objective evaluation of quality in cavity preparations.

Significant improvements in reliability of criteria measures were obtained by using a newly developed instrument to evaluate objectively the quality of cavity preparations in comparison to subjective ratings by the instructors of the quality of cavity preparations.

Dental Cavity Preparation

A second generation training simulator for acquisition of psychomotor skills in cavity preparation.

Thirty freshmen dental students, without prior dental technique laboratory experience, were divided randomly into two groups of 15 subjects. One group (control) was trained in the traditional way while the other group used a newly developed dental training simulator. The results for Class I cavity preparations in the mandibular right first molar indicate that a two-thirds reduction in training time occurred for the group trained by the simulator as compared to the control group. The mean training times were 57 minutes for the control group and 21 minutes for the experimental group. No statistically significant differences in quality were noted.

Adult