Task Load Index Research Articles

The Effect of Prehospital Clinical Trial-Related Procedures on Scene Interval, Cognitive Load, and Error: A Randomized Simulation Study

Introduction Globally, very few settings have undertaken prehospital randomized controlled trials. Given this lack of experience, there is a risk that such trials in these settings may result in protocol deviations, increased prehospital intervals, and increased cognitive load, leading to error. Ultimately, this may affect patient safety and mortality. The aim of this study was to assess the effect of trial-related procedures on simulated scene interval, self-reported cognitive load, medical errors, and time to action. Methods This was a prospective simulation study. Using a cross-over design, ten teams of prehospital clinicians were allocated to three separate simulation arms in a random order. Simulations were: (1) Eligibility assessment and administration of freeze-dried plasma (FDP) and a hemoglobin-based oxygen carrier (HBOC), (2) Eligibility assessment and administration of HBOC, (3) Eligibility assessment and standard care. All simulations also required clinical management of hemorrhagic shock. Simulated scene interval, error rates, cognitive load (measured by NASA Task Load Index), and competency in clinical care (assessed using the Simulation Assessment Tool Limiting Assessment Bias (SATLAB)) were measured. Mean differences between simulations with and without trial-related procedures were sought using one-way ANOVA or Kruskal-Wallis test. A p-value of <0.05 within the 95% confidence interval was considered significant. Results Thirty simulations were undertaken, representing our powered sample size. The mean scene intervals were 00:16:56 for Simulation 1 (FDP and HBOC), 00:17:22 for Simulation 2 (HBOC only), and 00:14:24 for Simulation 3 (standard care). Scene interval did not differ between the groups (p = 0.27). There were also no significant differences in error rates (p = 0.28) or cognitive load (p = 0.67) between the simulation groups. There was no correlation between cognitive load and error rates (r = 0.15, p = 0.42). Competency was achieved in all the assessment criteria for all simulation groups. Conclusion In a simulated environment, eligibility screening, performance of trial-related procedures, and clinical management of patients with hemorrhagic shock can be completed competently by prehospital advanced life support clinicians without delaying transport or emergency care. Future prehospital clinical trials may use a similar approach to help ensure graded and cautious implementation of clinical trial procedures into prehospital emergency care systems.

Physical and mental health impairments experienced by operating surgeons and camera-holder assistants during laparoscopic surgery: a cross-sectional survey.

Surgeons may experience physical and mental health problems because of their jobs, which may lead to chronic muscle damage, burnout, or even withdrawal. However, these are often ignored in camera-holder assistants during laparoscopic surgery. We aimed to analyze the differences between operating surgeons and camera-holder assistants. From January 1, 2022, to December 31, 2022, a cross-sectional survey was conducted to evaluate the muscle pain, fatigue, verbal scolding, and task load for operating surgeons and camera-holder assistants. The Nordic Musculoskeletal Questionnaire, the Space Administration Task Load Index, and the Surgical Task Load Index (SURG-TLX) were combined in the questionnaire. 2,184 operations were performed by a total of 94 operating surgeons and 220 camera assistants. 81% of operating surgeons and 78% of camera-holder assistants reported muscle pain/discomfort during the procedure. The most affected anatomic region was the shoulders for operating surgeons, and the lower back for camera-holder assistants. Intraoperative fatigue was reported by 41.7% of operating surgeons and 51.7% of camera-holder assistants. 55.2% of camera-holder assistants reported verbal scolding from the operating surgeons, primarily attributed to lapses in laparoscope movement coordination. The SURG-TLX results showed that the distributions of mental, physical, and situational stress for operating surgeons and camera-holder assistants were comparable. Like operating surgeons, camera-holder assistants also face similar physical and mental health impairments while performing laparoscopic surgery. Improvements to the working conditions of the camera-holder assistant should not be overlooked.

Real-time hand interaction and self-directed machine learning agents in immersive learning environments

Integration of extended reality (XR) in education is becoming popular to transform the traditional classroom with immersive learning environments. The adoption of immersive learning is accelerating as an innovative approach for science and engineering subjects. With new powerful interaction techniques in XR and the latest developments in artificial intelligence, interactive and self-directed learning are becoming important. However, there is a lack of research exploring these emerging technologies research with kinesthetic learning or “hands-one learning" as a pedagogical approach using real-time hand interaction and agent-guided learning in immersive environments. This paper proposes a novel approach that uses machine learning agents to facilitate interactive kinesthetic learning in science and engineering education through real-time hand interaction in the virtual world. To implement the following approach, this paper uses a chemistry-related case study and presents a usability evaluation conducted with 15 expert reviewers and 2 subject experts. NASA task load index is used for cognitive workload measurement, and the technology acceptance model is used for measuring perceived ease of use and perceived usefulness in the evaluations. The evaluation with expert reviewers proposed self-directed learning using trained agents can help in the end-user training in learning technical topics and controller-free hand interaction for kinesthetic tasks can improve hands-on learning motivation in virtual laboratories. This success points to a novel research area where agents embodied in an immersive environment using machine learning techniques can forge a new pedagogical approach where they can act as both teacher and assessor.

Effect of emotion and workload on expertise in programming

In recent times, few studies on program comprehension have incorporated the use of psycho-physiological devices and self-report tools to measure participants’ emotions and cognitive workload. The use of self-report scales is beneficial in settings where there is no access to biosensors or a need for a general understanding of programmers’ emotions and workload during learning or in an assessment of a large group. Hence, we designed a study that would use self-report tools — the Self-Assessment Manikin (SAM) test and NASA TLX (Task Load Index) to obtain the emotions and workload of the participants on two types of programming tasks (logical and conceptual). Our aim was to identify the relationship between emotions and expertise, and workload and expertise on conceptual and logical questions in timed and untimed conditions. Our findings indicate that participants showed Low Valence-High Arousal (LVHA) in timed conditions and High Valence-Low Arousal (HVLA) in untimed conditions. Findings further indicate that high performers showed High Valence-Low Arousal (HVLA) on conceptual questions and High Valence-High Arousal (HVHA) on logical questions, whereas low performers showed High Valence-Low Arousal (HVLA) on conceptual questions and Low Valence-High Arousal (LVHA) on logical questions. We found that participants had a higher workload in timed conditions than untimed conditions and had a higher workload on logical questions than conceptual questions. Furthermore, we employed machine learning algorithms to predict expertise using emotions and workload and the best classifier produced an accuracy of 71.4%, with 72% weighted precision, 71.5% weighted recall, and 71.11% weighted F-score.

Health anxiety and its association with perceived subjective workload in psychiatric nurses during the COVID-19 outbreak: a correlational study.

Health care professionals, especially nurses, experience added workload, and psychological impact during the COVID-19 outbreak. This study aimed to investigate health anxiety and its association with perceived subjective workload in nurses working in psychiatric hospital wards. This descriptive correlational study was conducted on 206 nurses working in the psychiatric wards of Razi Psychiatry Hospital in Tabriz, Iran, in 2020-2021. Census sampling was applied and data were collected using the National Aeronautics and Space Administration Task Load Index, and the Health Anxiety Inventory. Data were analyzed using descriptive statistics, t-tests, and Pearson correlation in SPSS software version 16. The mean (SD) of health anxiety and workload of nurses was 23/22(6/86) score range of 0-54 and 71.46 (12.37) score range of 0-100, respectively. The correlation between the mean of health anxiety and workload was significant only in the temporary dimension. Given the high workload and moderate level of health anxiety and the significant correlation between health anxiety and the temporary dimension of workload and the important role of appropriate workload in the health of nurses and the quality of nursing care, organizations and nursing managers should provide some strategies, like stuff shortage management in psychiatric wards and creating a suitable organizational culture.

Scale Worlds: Iterative refinement, evaluation, and theory-usability balance of an immersive virtual learning environment

Feedback-based iterative refinement is important in the development of any human-computer interface. The present work aims to evaluate and iteratively refine an immersive learning environment called Scale Worlds (SW), delivered via a head-mounted display (HMD). SW is a virtual learning environment encompassing scientific entities of a wide range of sizes that enables students an embodied experience while learning size and scale. Five usability experts performed think aloud while carrying out four interactive tasks in SW and compared three different design options during A/B testing. Improvement features based on the feedback from an earlier SW usability evaluation as well as HMD-specific features were examined. Usability experts completed the post-study system usability questionnaire, the NASA task load index, and a bipolar laddering survey that collected subjective perception of specific SW features. Results show that the progress panel (an improvement feature) was informative while the instructions (another improvement feature) caused clutter. The experts indicated clear usability preferences during A/B testing, which helped resolve three sets of theory-usability conflicts. The overall assessment of SW paved a path for theory-usability balance and provided valuable insights for designing and evaluating usability in immersive virtual learning environments.

Using Detection Response Task and NASA-TLX to Measure the Difference in Cognitive Workload Between Partially Automated Mode and Manual Mode: An On-Road Study

The purpose of this study is to investigate how partially automated vehicles affect cognitive load. The study involved an on-road experiment where 29 participants drove a Tesla in both partially automated and manual mode for up to 45 minutes. The researchers objectively measured the participants' cognitive workload using the Detection Response Task (DRT) and subjectively assessed it using NASA Task Load Index (NASA-TLX). The findings revealed that there was no significant difference in cognitive workload between the partially automated mode and manual mode in both objective and subjective measures. Our study expands the literature on the effects of partially automated vehicles on cognitive workload by using DRT and NASA-TLX. Further studies should adopt similar methodology with the addition of physiological and ocular measures.

Virtual reality exergame in older patients with hypertension: a preliminary study to determine load intensity and blood pressure

BackgroundLifestyle changes and physical activity can make an important contribution to reducing the risk factor for high blood pressure (BP). Whether virtual reality (VR) exergames are also appropriate and make a positive contribution to the reduction of BP has not yet been sufficiently investigated. Therefore, the aim of the study was to gain knowledge of the load intensities to be achieved during a VR exergame and to examine the short-term effects on BP.MethodsFor the preliminary study, 22 participants with hypertension over the age of 65 years were analyzed. The study took place in a mobile laboratory truck. All participants visited on two occasions. During visit 1, VR strength endurance training (VR-SET) and during visit 2, VR endurance training (VR-ET) was performed. Each VR session lasted approximately 25 min and was of a moderate intensity. Heart rate (HR) was measured across the entire session, as well as BP before and after the VR exergame. The Rating of Perceived Exertion (RPE) and task load using NASA Task Load Index were determined after each VR session. Included in the statistical analysis were the Shapiro–Wilk test, the paired t-test, the Wilcoxon test and ANOVA for repeated measures.ResultsDuring the “main part” (p < .001), at the “end” (p = .002) and for the “maximum HR” (p < .001), significant load differences between both VR sessions could be determined. In addition, significantly more participants in the VR-SET group achieved a moderate load intensity of at least 40% of heart rate reserve (p = .014). Regarding RPE, participants rated their subjectively perceived exertion significantly higher in the VR-SET than in the VR-ET (p = .028). Systolic BP decreased significantly in both VR sessions when compared before VR session and 5 min after VR session (p = .015; p = .003), as well as before VR session and 10 min after VR session (p = .018; p < .001).ConclusionsAn individual moderate load intensity of 40% can be reached during VR-SET. In addition, a positive short-term effect of the VR exergame on BP behavior (postexercise hypotension) was observed after both VR sessions. The preliminary results indicate that a VR exergaming could lead to blood pressure lowering effects for older people with hypertension.Trial registrationThe study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00022881, 07/09/2020, https://drks.de/search/de/trial/DRKS00022881).

890 Surgical Multidisciplinary Team Meetings Are Enhanced by Collaboration in the Metaverse

Abstract Aim Multidisciplinary team meetings (MDT-Ms) are utilised as a clinical decision-making tool. Currently, these are in-person or remote, using screen-sharing of patient health records including clinical findings, numerical data, and imaging (2D/3D). Immersive Virtual Reality (IVR) is an emerging technology allowing multiple care-providers to remotely interact with patient data in the metaverse. Our aim was to develop an IVR metaverse for MDT-M and test its feasibility and efficacy in the orthopaedic trauma setting. Method Interviews of users attending existing orthopaedic trauma MDT-Ms at a regional major trauma centre identified strengths, weaknesses, opportunities, and threats (SWOT analysis) for a novel platform. Iterative testing allowed feature development and curation of twenty-four simulated cases from previous admissions. User experience in pilot MDT-Ms was measured using the NASA Task Load Index (NASA-TLX) and System Usability Scale (SUS). Results An IVR metaverse platform was developed and four MDT-Ms were successfully conducted with healthcare professionals (n = 13). Participants found ‘data visualisation’ and ‘clinical decision-making’ effective in IVR: median 5 (IQR 4-5); and 5 (IQR 4-5) respectively. Ratings on ‘ease of communication’ in the metaverse were varied with a median of 3 (IQR 2-4.5). Qualitative analysis highlighted the strength of IVR for collaborative interrogation of 3D anatomy and injury patterns. The NASA-TLX domain ‘task performance’ was rated consistently highly. Conclusions Healthcare professionals can conduct MDT-Ms using a novel platform on commercially available IVR headsets. Participants were able to collaboratively interrogate clinical data, facilitating enhanced discussion, decision-making, and perceived task performance. Future iterations will focus on role designation to improve communication in MDT-Ms.

Effect of Mixed Reality on Delivery of Emergency Medical Care in a Simulated Environment

Mixed-reality (MR) technology has the potential to enhance care delivery, but there remains a paucity of evidence for its efficacy and feasibility. To assess the efficacy and feasibility of MR technology to enhance emergency care delivery in a simulated environment. This pilot randomized crossover trial was conducted from September to November 2021 at a single center in a high-fidelity simulated environment with participants block randomized to standard care (SC) or MR-supported care (MR-SC) groups. Participants were 22 resident-grade physicians working in acute medical and surgical specialties prospectively recruited from a single UK Academic Health Sciences Centre. Data were analyzed from September to December 2022. Participants resuscitated a simulated patient who was acutely unwell, including undertaking invasive procedures. Participants completed 2 scenarios and were randomly assigned to SC or MR-SC for the first scenario prior to crossover. The HoloLens 2 MR device provided interactive holographic content and bidirectional audiovisual communication with senior physicians in the MR-SC group. The primary outcome was error rate assessed via the Imperial College Error Capture (ICECAP) multidimensional error-capture tool. Secondary outcomes included teamwork (Observational Teamwork Assessment for Surgery [OTAS]; range, 0-6 and Teamwork Skills Assessment for Ward Care [T-SAW-C]; range, 1-5), scenario completion, stress and cognitive load (NASA Task Load Index [NASA-TLX; range 0-100]), and MR device user acceptability. A total of 22 physicians (15 males [68.2%]; median [range] age, 28 [25-34] years) were recruited. MR technology significantly reduced the mean (SD) number of errors per scenario compared with SC (5.16 [3.34] vs 8.30 [3.09] errors; P = .003), with substantial reductions in procedural (0.79 [0.75] vs 1.52 [1.20] errors; P = .02), technical (1.95 [1.40] vs 3.65 [2.03] errors; P = .01), and safety (0.37 [0.96] vs 0.96 [0.85] errors; P = .04) domains. MR resulted in significantly greater scenario completion rates vs SC (22 scenarios [100%] vs 14 scenarios [63.6%]; P = .003). It also led to significant improvements in the overall quality of teamwork and interactions vs SC as measured by mean (SD) OTAS (25.41 [6.30] vs 16.33 [5.49]; P < .001) and T-SAW-C (27.35 [6.89] vs 18.37 [6.09]; P < .001) scores. As reported via mean (range) NASA-TLX score, there were significant reductions for MR-SC vs SC in participant temporal demands (38 [20-50] vs 46 [30-70]; P = .03) and significant improvements in self-reported task performance (50 [30-60] vs 39 [10-70]; P = .01). Overall, 19 participants (86.4%) reported that they were more confident in making clinical decisions and undertaking clinical procedures with MR support. This study found that the use of MR technology reduced error, improved teamwork, and enhanced practitioner confidence when used to support the delivery of simulated emergency medical care. ClinicalTrials.gov Identifier: NCT05870137.

Laparoscopic ultrasonography of the liver is feasible and safe in dogs.

To describe the feasibility and technique for performing laparoscopic ultrasound (LUS) of the liver in dogs. 12 client-owned dogs presenting for elective laparoscopic surgery from January 1, 2022, to October 31, 2022. Laparoscopic exploration and LUS of the liver were performed in all dogs. Dogs were positioned in reverse Trendelenburg and laterally rotated to facilitate access to all liver lobes. Time to perform laparoscopic exploration and LUS, ability to visualize and access each liver lobe entirely, and any complications were recorded. Each dog underwent an elective laparoscopic procedure. The surgeon completed a National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire after surgery. Mean body weight was 25.9 kg (SD, ± 4.1 kg; range, 5.7 to 62 kg). All liver lobes were scanned to the level of the hilus in 10/12 dogs. In 2 dogs, the caudate lobe could not be completely imaged. Median time to perform LUS was 9 minutes (IQR, 5 to 16.5 minutes), and median NASA-TLX score was 9/100 (IQR, 6.3 to 20). There was a significantly strong negative correlation between time to perform LUS (r = -0.77; P = .0037) and NASA-TLX score (r = -0.84; P = .0006) with trial number. Minor complications occurred in 2 dogs during laparoscopic exploration. No complications occurred during LUS. LUS was feasible and safe in all dogs. The right lateral and caudate lobes were occasionally challenging to access. Technical demand and time to perform LUS improved with experience, suggesting a learning curve. Evaluation of LUS in dogs with clinical disease is warranted.

Job satisfaction and perception of workloads among dietitians and nutritionists registered in South Africa

Background: Personal perspective concerning work demands directly impacts quality health care and patient satisfaction. Little is known about job satisfaction amongst dietitians and nutritionist, while workload has not previously been studied in this population. Methods: A descriptive cross-sectional study was performed using an online questionnaire. Data were collected on sociodemography. Job satisfaction was measured with Spector’s Job Satisfaction Survey (JSS) (including an added subscore for resource availability) and workload with the National Aeronautics and Space Administration Task Load Index (NASA-TLX). Results: Respondents (n = 238) had a median age of 32.0 years (IQR: 27−39 years); 92.4% were female; 95.7% were dietitians, 2.4% were nutritionists and 18.9% had a postgraduate degree. Respondents had practised the profession for a median of 8 years (IQR 3−15 years), and 225 were in dietetic and nutrition-related jobs. Median scores indicated that they were slightly satisfied with their jobs (n = 224) and experienced slightly high workload (n = 224). Most respondents were moderately satisfied with the nature of their work and found it rewarding. The median scores for salaries, promotion opportunities, work environment and availability of resources were low. Total JSS was higher in older and more experienced dietitians and nutritionists than in younger ones (p < 0.05). Those employed in the government sector (n = 100) experienced higher physical demands and levels of frustration, and had lower JJS than those employed elsewhere (n = 124), particularly regarding promotion opportunities and resources availability. Conclusion: Despite being generally positive towards practising their profession, South African dietitians and nutritionists, particularly in the public health sector, experienced only slight job satisfaction, related to salary and promotion issues and lack of resources, and were slightly overworked. Understanding the factors that shape perceptions of work within nutrition and dietetics may assist managers in recruiting and retaining a highly skilled workforce, particularly in developing countries with overburdened healthcare systems.

Is it cognitive effort you measure? Comparing three task paradigms to the Need for Cognition scale.

Measuring individual differences in cognitive effort can be elusive as effort is a function of motivation and ability. We report six studies (N = 663) investigating the relationship of Need for Cognition and working memory capacity with three cognitive effort measures: demand avoidance in the Demand Selection Task, effort discounting measured as the indifference point in the Cognitive Effort Discounting paradigm, and rational reasoning score with items from the heuristic and bias literature. We measured perceived mental effort with the NASA task load index. The three tasks were not correlated with each other (all r's < .1, all p's > .1). Need for Cognition was positively associated with effort discounting (r = .168, p < .001) and rational reasoning (r = .176, p < .001), but not demand avoidance (r = .085, p = .186). Working memory capacity was related to effort discounting (r = .185, p = .004). Higher perceived effort was related to poorer rational reasoning. Our data indicate that two of the tasks are related to Need for Cognition but are also influenced by a participant's working memory capacity. We discuss whether any of the tasks measure cognitive effort.

Usability evaluation of augmented reality visualizations on an optical see-through head-mounted display for assisting machine operations

This study explores the effect of using different visual information overlays and guiding arrows on a machine operation task with an optical see-through head-mounted display (OST-HMD). Thirty-four participants were recruited in the experiment. The independent variables included visual information mode (text, animation, and mixed text and animation) and the use of guiding arrows (with and without arrows). In addition, gender difference was also an objective of this study. The task performance indicators were determined based on task completion time and error counts as well as subjective measures (system usability scale, NASA task load index, and immersion scale). This study used the mixed analysis of variance design to evaluate the main and interaction effects. The results showed that males performed better when using the mixed text and animation mode. Females performed better when using the text mode. In addition, using the mixed text and animation mode demonstrated the best outcome in system usability scale and NASA task load index. For the use of guiding arrows, the task completion time was reduced and the system usability scale, NASA task load index, and immersion scale showed positive effects.

Fatigue in elite fencing: Effects of a simulated competition.

The fatigue induced by fencing remains scarcely investigated. We aimed to investigate both objective (neuromuscular performance fatigability) and subjective (perceived fatigue, effort, and workload) manifestations of fatigue in elite fencers following a five-bout simulated competition. Changes in countermovement jump height, knee extensors maximal isometric torque, rate of torque development, voluntary activation, and contractile response to muscular electrical stimulation were measured in 29 elite fencers [12 epee (6 women), 11 saber (5 women), and 6 foil]. Perceived fatigue and effort were evaluated with visual analog scales, and the perceived workload with the NASA Task Load Index scale. During the competition, maximal torque and rate of torque development decreased by 1.6% (p = 0.017) and 2.4% (p < 0.001) per bout, respectively. Perceived fatigue before each bout increased (12% per bout), with similar values observed at the end of all bouts (bout × period interaction: p < 0.001). Perceived effort increased during the bouts (10% per period, p < 0.001) and during the competition (3% per bout, p = 0.011). Perceived mental demand increased during the competition (2% per bout, p = 0.024). These results suggest that elite fencers needed to increase the allocation of mental rather than physical resources to the task to counterbalance the deleterious effect of fatigue on performance.

Robotic arm training in neurorehabilitation enhanced by augmented reality – a usability and feasibility study

BackgroundRobotic therapy and serious gaming support motor learning in neurorehabilitation. Traditional monitor-based gaming outputs cannot adequately represent the third dimension, whereas virtual reality headsets lack the connection to the real world. The use of Augmented Reality (AR) techniques could potentially overcome these issues. The objective of this study was thus to evaluate the usability, feasibility and functionality of a novel arm rehabilitation device for neurorehabilitation (RobExReha system) based on a robotic arm (LBR iiwa, KUKA AG) and serious gaming using the AR headset HoloLens (Microsoft Inc.).MethodsThe RobExReha system was tested with eleven adult inpatients (mean age: 64.4 ± 11.2 years; diagnoses: 8 stroke, 2 spinal cord injury, 1 Guillain-Barré-Syndrome) who had paretic impairments in their upper limb. Five therapists administered and evaluated the system. Data was compared with a Reference Group (eleven inpatients; mean age: 64.3 ± 9.1 years; diagnoses: 10 stroke, 1 spinal cord injury) who trained with commercially available robotic therapy devices (ArmeoPower or ArmeoSpring, Hocoma AG). Patients used standardized questionnaires for evaluating usability and comfort (Quebec User Evaluation of Satisfaction with assistive technology [QUEST]), workload (Raw Task Load Index [RTLX]) and a questionnaire for rating visual perception of the gaming scenario. Therapists used the QUEST, the System Usability Scale and the short version of the User Experience Questionnaire.ResultsTherapy with the RobExReha system was safe and feasible for patients and therapists, with no serious adverse events being reported. Patients and therapists were generally satisfied with usability. The patients’ usability ratings were significantly higher in the Reference Group for two items of the QUEST: reliability and ease of use. Workload (RTLX) ratings did not differ significantly between the groups. Nearly all patients using the RobExReha system perceived the gaming scenario in AR as functioning adequately despite eight patients having impairments in stereoscopic vision. The therapists valued the system’s approach as interesting and inventive.ConclusionsWe demonstrated the clinical feasibility of combining a novel robotic upper limb robot with an AR-serious game in a neurorehabilitation setting. To ensure high usability in future applications, a reliable and easy-to-use system that can be used for task-oriented training should be implemented.Trial registrationEthical approval was obtained and the trial was registered at the German Clinical Trials Register (DRKS00022136).

Impact of experience on the sensitivity, acceptability, and intrusive of two subjective mental workload techniques: The NASA TLX and workload profile.

Today's work environments have high cognitive demands, and mental workload is one of the main causes of work stress, human errors, and accidents. While several mental workload studies have compared the mental workload perceived by groups of experienced participants to that perceived by novice groups, no comparisons have been made between the same individuals performing the same tasks at different times. This work aims to compare NASA Task Load Index (NASA-TLX) to Workload Profile (WP) in terms of their sensitivity. The comparison considers the impact of experience and task differentiation in the same individual once a degree of experience has been developed in the execution of the same tasks. It also considers the acceptability and intrusivity of the techniques. The sample consisted of 30 participants who performed four tasks in two sessions. The first session was performed when participants had no experience; the second session was performed after a time of practice. Mental workload was assessed after each session. Statistical methods were used to compare the results. The NASA-TLX proved to be more sensitive to experience, while the WP showed greater sensitivity to task differentiation. In addition, while both techniques featured a similar degree of intrusivity, the NASA-TLX received greater acceptability. The acceptability of WP is low due to the high complexity of its dimensions and clarifying explanations of these may be necessary to increase acceptability. Future research proposals should be expanded to consider mental workload when designing work environments in current manufacturing environments.

Quantification of cognitive ergonomic factors and task performance for the use of passive upper limb exoskeleton while performing overhead tasks.

Exoskeleton has been proposed as a solution for musculoskeletal problems. Designed for physical attributes, it is crucial to determine the effect of its usage on cognitive aspects during task execution. This study aims to quantify cognitive ergonomic factors and task performance for the use of passive upper limb exoskeleton while performing overhead tasks. Ten male participants (mean age of 23.2 years (SD= 0.6)) took part in single and dual-task experiments. Subjective ratings using NASA Task Load Index (NASA-TLX) and Situation awareness rating technique (SART), physiological measure using Heart Rate Variability (HRV) and task performance (number of error) were measured. The dual-task setup reveals that there were strong positive correlations between the overall workload and number of errors percentage, which was statistically significant (r = 0.822, n = 10, p = 0.004). This finding is crucial as a reference for designers, developers, and policymakers in optimizing and sustaining task performance.

Comparing driver reaction and mental workload of visual and auditory take-over request from perspective of driver characteristics and eye-tracking metrics

The objective of this study was to compare the driver’s reaction and mental workload of different take-over requests (TOR) modalities concerning driver characteristics in semi-autonomous driving when the driver is engaged in different non-driving related tasks. A driving simulator was developed for two TOR modalities (visual and auditory). Thirty-three individuals participated in the driving simulation experiment. NASA Task Load Index, driver characteristics (driving style questionnaire and work-load sensitive questionnaire), and eye-tracking metrics were collected. Through the structural equation model, we found that driving style affects driver’s mental work-load and reaction sequence in a visual TOR alert situation, while in auditory TOR alert situation, a driver characteristics have no significance on mental workload and reaction sequence. Strong correlation between mental workload and reaction sequence was only found in the auditory TOR alert situation. These results can be used to develop an adaptive multi-modal interface that take driver characteristics into account.

Human Performance in Highly Automated, Cyber Vulnerable Unmanned Aerial Systems: Effects of Operators’ Background and Task Load

This article evaluated the effects of operator background and task load on operator ability to detect and respond to cyber events while controlling multiple unmanned aerial systems (UAS). Cyber physical systems (CPS) are susceptible to cyber threats and associated events via connections critical to their operations. The effects of cyber intrusions on UAS operator performance as a function of background and task load have been understudied. Fifty-one operators with different backgrounds (Aviators, Gamers and Non-Gamers; n = 17 per group) were evaluated across two levels of task load (in-the-loop (ITL) and out-of-the-loop (OTL)) while controlling a simulation of multiple UAS involving cyber events. Cyber events represented spoofed information that could not be corroborated with available secondary information/displays. Multivariate analysis of variance was used to analyze the effect of background and task load on operator performance, subjective perception of workload (assessed using the NASA Task Load Index), and trust. Nongamers responded to cyber events 62.8% and 67.7% slower than aviators and gamers, respectively. Mean response times across task load conditions were substantially longer for cyber events (128.9 s) than for noncyber, “real” events (42.8 s). Scenario type (ITL/OTL) was statistically significant for workload, cyber classification, and cyber action response. The findings may inform recruitment criteria for future UAS operators. Individuals with gaming experience may be as adept at responding to cyber events while operating multiple UAS as aviators. Cyber events are likely to affect the performance of the overall CPS due to their impact on the human operator.