Evaluation of mental workload in automation design for a main control room task

Background: The amount of mental resources required to perform simultaneously a series tasks is considered as mental workload (MWL). High and Low mental workload in the workplace is usually associated with mental fatigue, decreased performance, human error, and even harmful long-term health effects. Among the various MWL assessment techniques, the outcome measures such as questionnaires are easier and more practical in workplace settings. We aimed to compare the three current commonly advocated and used questionnaires. Material and Methods: Three common different outcome measures for evaluation of the MWL are NASA Task Load Index (NASA-TLX), Subjective Workload Assessment Technique (SWAT), and the CarMen-Q workload questionnaire. Among them the NASA-TLX is well known and more popular with six subscales that are used extensively in industrial and official workplaces. SWAT is the simplest one with three dimensions. The NASA-TLX is preferable method because of its higher sensitivity, especially in low MWL conditions. The CarMen-Q questionnaire is a new questionnaire with 29 items and 4 subscales that focuses on cognitive workload and mental fatigue. Conclusion: SWAT is the simplest and less sensitive measure than the NASA-TLX and CarMen-Q questionnaires. In contrast, the NASA-TLX is widely used and more known instrument for MWL evaluation.

Objective To compare the subjects' scores of National Aeronautics and Space Administration-task load index (NASA-TLX), the indexes of ECG and performance between the reverse target tracking task and the ordinary target tracking task which simply simulatereverse operationof carrier aircraft landing, and to preliminarily investigate the effect ofreverse operationon pilot's mental workload and its influence factors. Methods Twenty-five young male subjects accomplished the reverse and the ordinary target tracking tasks with two degrees of difficulty. ECG signals were recorded during the resting period before the task, periods of each task and the resting period after the task. Each subjects filled in NASA-TLX scale after the completion of each task and had a score feedback for each task. The scores of NASA-TLX and the indexes of performance were analyzed by analysis of variance (ANOVA) in 2×2 factorial design. The indexes of ECG were analyzed by Friedman M test and the multiple comparisons were carried out by LSD-t test. Results The scores of NASA-TLX and the average tracking distance of the reverse target tracking task were higher than those of the ordinary target tracking task (F=21.70, 16.14, P<0.05) and the highest appeared in the reverse dual task (F=6.67, P<0.05). HR also had the corresponding change (χ2=34.87, P<0.05), but the indexes of HRV had no significant differences. Conclusions Mental workload of the reverse operation task is higher than that of the ordinary operation task if the other conditions are the same. The reverse operation impacts mental workload severer when more information processing is required. Mental demand, physical demand and frustration level are the major influence factors of causing high mental workload in reverse operations. Key words: Workload; Cognition; Habituation, psychophysiologic; Work capacity evaluation; Electrocardiography

Background: Academic staff have different roles which may impose a high mental workolad on them and affect their cognitive function. This study was designed to assess different subscales of mental worklaod and cognitive function in university academic staff. Methods: This was a cross-sectional study on 86 faculty members of Shahid Sadoughi University of Medical Sciences. Stratified sampling was used to select participants from different schools. The participants were divided into basic sciences and clinical faculty members. Mental workload was assessed by National Aeronautics and Space Administration-Task Load Index (NASA-TLX). Cognitive function was assessed by Stroop test. Data were analyzed by SPSS 26 using Shapiro-Wilks test, Student’s T-test, Mann Whitney U test, univariate ANOVA, and Kruskal-Wallis test. The level of significance was 0.05. Results: Mean age and work history of the participants was 43.6±8.6 yr. and 11.7±9.1 yr., respectively. Mental workload, especially two aspects of mental demand and performance, was high and it was significantly higher in the participants from school of medicine and among those with executive/administrative responsibilities. From subscales of mental workload, physical demand was significantly higher among clinical than basic sciences faculty members (p&lt;0.05). Among different aspects of cognitive function, only numbers of congruent errors were significantly higher among clinical faculties. Mental workload and cognitive function were not significantly correlated. Conclusion: This study showed a high level of mental workload in university academic staff, especially in clinical faculty members, but this high mental workload did not affect their cognitive function.

This case of study takes place at a university’s information technology center where it is possible to damage computers seriously during the initial checking due to procedural or human errors. Thirteen technicians were observed in this work. They perform tasks and subtasks suffering from mental and physical workload that can cause human errors since an average of 300 maintenance orders must be attended weekly. According to the participants, changing the power supply is the task that can cause the most severe damage on computers in case of error, so human error identification and mental workload evaluation techniques were applied using TAFEI and NASA TLX correspondingly. Results found that human errors are mainly due to the poor identification of the equipment waiting to be repaired, while Mental Demand is the highest source for mental workload. Recommendations are given to prevent human errors and reduce mental workload.

Digitalized nuclear instruments and control systems have become the main stream design for the main control room (MCR) of advanced nuclear power plants (NPPs) nowadays. Digital human-system interface (HSI) could improve human performance and, on the other hand, could reduce operators’ situation awareness as well. It might cause humans making wrong decision during an emergency unintentionally. Besides, digital HSI relies on computers to integrate system information automatically instead of human operation. It has changed the operator’s role from mainly relating operational activity to mainly relating monitoring. However, if operators omit or misjudge the information on the video display units or wide display panel, the error of omission and error of commission may occur. Therefore, how to avoid and prevent human errors has become a very imperative and important issue in the nuclear safety field. This study applies Performance Evaluation Matrix to explore the potential human errors problems of the MCR. The results show that the potential problems which would probably affect to the human performance of the MCR in advanced NPPs are multiple accidents, pressure level, number of operators, and other factors such as working environmental.

BackgroundDifficult surgical procedures may result in a higher mental workload, leading to increased fatigue and subsequent errors. This study was aimed to investigate the effect of repeated simulation training in ureterorenoscopy in a high-fidelity setting on the performance and mental workload of novice operators.MethodsMedical students voluntarily participated in the present simulation study. After a didactic and video-based lecture, they underwent simulation training involving a renal stone case, including a rigid cystoscope component (task 1, performing a WHO checklist, assembling a scope, and insertion of a guide-wire and an access sheath after examining the bladder) and a flexible ureterorenoscope component (task 2, retrieving a stone located in the upper calyx using a basket after inspecting the upper, middle, and lower calyx). Training was performed in a mock operating theater. Technical skills were assessed by one author (an experienced urologist) onsite using an Objective Structured Assessment of Technical Skills (OSATS) score at each training session. The mental workload was subjectively evaluated by the National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire after each training session.ResultsSeventeen students completed a minimum of 6 training sessions (male: female = 10: 7, median age of 22) over a median of 21 days (range, 10–32). In both tasks 1 and 2, the OSATS score improved over the 6 sessions with evidence of plateauing (MANOVA model, task 1: p < 0.0001, task 2: p < 0.0001). In contrast, the NASA-TLX score persistently decreased without plateauing (task 1: p = 0.0005, task 2: p = 0.0028).ConclusionsUnder repeated simulation training in ureterorenoscopy in a high-fidelity setting, participants showed a continual decrease of the mental workload, while the improvement of technical skills reached a plateau over the 6 sessions. Our study showed the important benefit of simulation training to reduce the mental workload by repeated scenario training before actual clinical practice.

Effect of user interface layout on the operators’ mental workload in emergency operating procedures in nuclear power plants

OCCUPATIONAL APPLICATIONS The findings from the current study illustrate the adverse effects of concurrent physical and mental demands on shoulder muscle activation. Furthermore, the results also suggest that the effects of concurrent physical and mental demands are more pronounced during static, as opposed to dynamic, exertions. As such, it is important to consider the interaction of said work parameters (i.e., force levels, mental demands, and type of exertion) when evaluating/designing tasks. Occupational tasks requiring concurrent physical and mental work should be redesigned to reduce static loading (by changing postures or providing frequent breaks). With tasks requiring static exertions, other physical parameters (such as force) should be reduced to minimize interference due to additional cognitive processing. To conclude, concurrent physical and mental demands affect muscle activation and impede worker performance; ergonomists should consider this interaction during task design/redesign, evaluations of injury risk, and potential causal models of injury development. TECHNICAL ABSTRACT Background: Static work is considered an occupational risk factor in the development of injuries, thus there is an emphasis on employing dynamic exertions to work tasks. With workers experiencing concurrent physical and mental demands in their daily jobs, it is unclear whether these exertion types affect overall task demands differentially. Objective: The aim of this study was to compare exertion-dependent physiological responses due to concurrent physical and mental workload during intermittent shoulder exertion. Methods: Twelve young participants, balanced by gender, performed intermittent static and dynamic shoulder abduction for 3 minutes at three levels of physical workload (low, moderate, and high) in the absence and presence of a mental arithmetic task. Study measures included muscle activity, muscle oxygenation, motor and mental arithmetic task performance, and subjective responses (NASA-Task Load Index and Borg CR10 Scale). Results: Static exertions and higher physical demands adversely affected physiological responses (i.e., muscle activity and oxygenation) and performance measures, and they were associated with higher levels of perceived exertion and workload. Additional mental demands negatively affected muscle activity, mental task performance, and subjective workload measures. However, these results were more pronounced during static exertions at high physical demand levels. Conclusions: Results indicated that certain job parameters (static exertions and high physical demands) are more susceptible to interference with mental demands than others (dynamic exertions and low demands). When assessing overall demands placed on workers during concurrent physical and mental work, it is important to consider the interaction of work parameters, specifically physical demand levels and exertion type, with mental demands.

BACKGROUND:Public health and improving the working conditions of people working in hospitals is very important because the health of nurses will have a significant impact on community health. Mental workload is a fundamental concept in the job. Therefore, it is very important to know the relation between mental workload and human performance, especially in nurses. The aim of this study was to determine the relationship between workload with cognitive failures and needle sticks in nurses of Alzahra Hospital in Isfahan.MATERIALS AND METHODS:This descriptive cross-sectional study was conducted on 245 nurses who worked in Al-Zahra Hospital in Isfahan. For collecting data, National Aeronautics and Space Administration Task Load Index (NASA-TLX), the Cognitive Failure questionnaire (CFQ), and accidental needle stick injuries questionnaire were used. Data were collected and analyzed by using SPSS.RESULTS:The mean ± SD of the age of the participants was 35.85 ± 7.15 years. There is a significant relationship between the demographic variables and the frequency of needle stick (P.value < 0.05). The mean of workload among the nurses was 81.75 ± 9.8. In addition, the mean of cognitive failure was 63.46 ± 7.92. The correlation between workload and cognitive failure was not significant (R = -0.017, P.value > 0.05). There is a significant difference between the workload mean (P.value < 0.05) and no significant difference between the cognitive failure mean (P.value > 0.05) in the two groups with needle stick experience and without needle stick experience.CONCLUSION:Needlestick is one of the most common accidents that usually occurs among health workers. Many factors affect the occurrence of these injuries. High mental workload can cause accidents and injuries by affecting the cognitive abilities of nurses. Therefore, it is important to manage the work schedule, training, supervision, as well as complying with safety and health procedures and standards in this occupational group.

PT XXX specializes in producing processed shrimp products using a make-to-order system, with large quantities distributed directly to consumers across various countries. The quality and precision of these products hinge on the effectiveness of the production process, in which labor plays a pivotal role. This study aims to assess the mental workload level of workers at the peel-off station using the NASA Task Load Index (NASA-TLX) and to identify key factors influencing mental workload. Data were collected through direct observation and interviews using questionnaires targeted at managers, staff, and production line workers, focusing on issues specifically encountered at the peel-off station. A theoretical framework for mental workload measurement, combined with the NASA-TLX methodology, was employed for analysis. Results show that, among a workforce of 47 employees aged 18-35 years, mental workload scores ranged from 32 to 42, placing them in the “rather high” category (30-49). This indicates frequent fatigue among workers. Mental Demand (MD) emerged as the most influential factor, attributed to the high cognitive load and necessary acclimation to the working environment at the peel-off station. Additionally, the findings suggest that mental workload is positively correlated with age, where increased age corresponds to a higher perceived mental workload.

In making mine roads, workers carry out work in conditions that are less comfortable carrying out work activities for long periods of time. For example, surveyors carry out their activities from morning to evening in hot or rainy weather conditions and require little time. Supervise the control of work so that it complies with the directions and time that has been determined. In carrying out these activities, high energy and precision is required, resulting in mental and physical workload. By carrying out this research, an evaluation of mental workload will be carried out to find out how much mental workload is felt by workers in carrying out work activities and what load factors most influence workers' mental workload. The analysis was carried out using the NASA-TLX method to identify the mental workload experienced by workers. The results of data processing show that the section that has the highest workload is the supervisory section with an average of 81.1, then the operator section with an average value of 80.9, and the lowest is the survey section with an average value of 80. In the shift comparison The workload for operators on the morning shift has a total score of 822, while on the night shift the total score is 796. Then on the morning shift the supervisor has a higher workload with a total score of 335, while on the night shift the total score is 314. So it can be seen that the workload during the shift morning shift is greater than the night shift.

Nursing is among the most stressful professions. Studies that examine possible factors that influence the mental workload (MWL) of nurses are of fundamental importance, because through these results, efforts can be concentrated on improving their working conditions more efficiently. To investigate the influence of hospital infection on the MWL of nurses in an intensive care unit (ICU). Cross-sectional and descriptive study, with a quantitative approach. Three research instruments were used: a sociodemographic questionnaire, the NASA Task Load Index (NASA-TLX) and the Nursing Work Index-Revised Brazilian version (B-NWI-R). The sample consisted of 30 nurses from the ICU of a public hospital in João Pessoa city, Brazil, during the daytime period, and the Spearman correlation test (α= 0,05) was applied to verify associations. There was a high MWL among nurses, with a NASA-TLX weighted average of 66.38 (SD±15.0). Correlations were found between the levels of hospital infection in the ICU and the MWL of the nurses (r = 0.654, p < 0.01); in the nurses' care of patients with urinary tract infection, the correlation is 0.546, p < 0.01; if care is provided to patients with lung problems, the correlation is 0.563, p < 0.01 The ICU presented a favorable environment to nursing practices, with means lower than 2.5, according to the B-NWI-R. The MWL of the nurses was associated with the hospital infection levels of the intensive care sector studied. It was found that the MWL of nurses in relation to hospital infection in the ICU increased by 42.8%. This MWL is impacted by 29.8% when nurses' care is linked to patients with urinary infection. But if care is provided to patients with lung problems, this percentage rises to 31.7.

We investigated variable autonomy in a teleoperated robot navigation task within a simulated office environment, focusing on who controls the shift between levels of automation (LoA). Two switch control modes—human-initiated (HI) and robot-initiated (RI)—were examined. The study assessed whether these modes influence operators’ cognitive workload, situational awareness (SA), and task performance. The task involved two LoA conditions: teleoperation (low LoA) and remote monitoring (high LoA), while participants simultaneously performed a secondary task. Task performance was measured through completion time, collision rates, time spent in low LoA, and secondary task performance. Operator-related measures included workload National Aeronautics and Space Administration Task Load Index (NASA-TLX), trust, ease of use, and perceived SA. The results revealed a clear tradeoff between operational efficiency and situational awareness. The RI mode improved task efficiency and reduced workload but compromised SA, whereas HI mode enhanced SA at the cost of efficiency. These findings highlight the inherent tension between automation-driven performance gains and operator’s cognitive engagement. The study contributes to the understanding of variable autonomy in human–robot collaboration (HRC) and underscores the need to evaluate both operator experience and task performance when designing teleoperation systems for habituated environments.

Objectives: This study aimed at measuring the mental and physical workload and its association with the prevalence of wrist disorders. Methods: This cross-sectional study was conducted on 120 female workers working in the assembly line of a porcelain company. The mental and physical workloads and also the prevalence of wrist disorders were measured using the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) questionnaire, the OCRA method, and the Nordic musculoskeletal questionnaire for wrists and hands, respectively. Results: The results showed that 63.3% of the participants had discomfort in their wrist and hands. The Mann-Whitney test results showed that OCRA risk levels were significantly higher in those with wrist pain than those without. The NASA-TLX results revealed that the physical demands and effort (78.79 ± 19.562 and 78.37 ± 20.002, respectively) had the higher scores among the 6 subscales of NASA-TLX, which were significantly higher in those with wrist pain. Conclusions: The findings suggested a high rate of physical and mental workloads and also the wrist disorders in the assembly line workers of the porcelain company. It seems that mental workload is one of the risk factors associated with the incidence of MSDs. Therefore, the high amount of mental workload should be considered as a risk factor.

PT XYZ is one of the companies in Indonesia engaged in providing telecommunications products. There are several interconnected and systematic teams at PT XYZ including the OBL, SM/PRPO, Solution and Reporting Data teams which are related to human resources and have jobs that create their own workload in order to achieve the tasks that have been done. PT XYZ wants to know the value of the large mental workload that the workforce gets on its four teams by applying the NASA TLX method. The aim of this research is to be able to identify events and investigate the risks of mental workload, rating levels and suggestions for improving work systems for employees of the OBL, SM/PRPO, Solution and Reporting Data teams at PT XYZ. Based on the mental workload score using the NASA-TLX method, it was found that 14 employees had a very high mental work load, while 2 employees had a high mental work load. Then, for the most dominant variable, it can affect the final mental work load according to the questionnaire that was given before, namely effort and performance. Proposals for improvements that can be shared in order to reduce the score/rating of employees' mental workload, namely by adding employees according to the needs of the relevant team members and also the company, training activities on anticipating mental workload and sharing sessions among fellow employees regarding hearings about complaints annoyed while working.