Task Load Research Articles

Cortical and Subcortical Substrates of Working Memory in the Right Hemisphere: A Connectome-Based Lesion-Symptom Mapping Study

Working Memory (WM) is a cognitive system whose crucial role is to temporarily hold and manipulate information. Early studies suggest that verbal WM is typically associated with left hemisphere (LH) brain regions, while the processing of visuospatial information in WM more specifically depends on the right hemisphere (RH). However, recent evidence suggests a more complex network involving both hemispheres' prefrontal and posterior parietal cortices in these processes. Unfortunately, previous lesion studies often examined only one modality (either verbal, or visuospatial) or one hemisphere, which limits the possible conclusions regarding non-lateralized hemispheric involvement. Using connectome-based lesion-symptom mapping on a large sample of patients with left (LBD) and right (RBD) focal brain damage, we examined whether gray matter damage and white matter disconnections predict deficits of WM updating in an N-back task. Patients were examined with two WM tasks that differed regarding modality (verbal, spatial) and cognitive load (1-back, 2-back). Behavioral outcomes indicated that RBD patients showed significant deficits in WM updating, regardless of task modality or load. This observation was supported by whole-brain voxel-based analysis, revealing associations between WM deficits and gray matter clusters in the RH. Specifically, damage to the right lateral frontal cortex including the brain region homologous to Broca’s area was associated with verbal WM deficits, while damage to the right inferior parietal lobe and posterior temporal cortex predicted spatial WM deficits. Additionally, white matter analyses identified severely impacted tracts in the RH, predicting deficits in both verbal and spatial WM. Our findings suggest that the mental manipulation of both verbal and visuospatial information in WM updating relies on the integrity of the RH, irrespective of the specific type of information held in mind.

Tele-education in point-of-care ultrasound training

BackgroundTraditionally, ultrasound skills have been taught through a one-on-one approach, where instructors physically guide learners’ hands at the bedside or in the workshop. However, this method is frequently challenged by scheduling and cost limitations. Our objective was to create a tele-education model for point-of-care ultrasound training and evaluate its effectiveness and its impact on learners’ perceived workload compared to conventional education and self-directed learning methods.MethodsWe conducted a 3-arm randomized trial, comparing tele-education (TE), conventional education (CE) and self-directed learning (SL) methods. All subjects underwent online didactic lectures prior to a hands-on ultrasound workshop. The TE group utilized an ultrasound machine equipped with a speakerphone, a webcam for direct visualization of learner’s hand maneuvers, and an analog-to-video converter for the real-time streaming of ultrasound images. This configuration enabled remote instructors to provide immediate verbal feedback to learners. In contrast, the CE group received in-person coaching, while the SL group had no instructors present. Following the coaching session, subjects completed a scenario-based skill test and a survey on the National Aeronautics and Space Administration task load index (NASA-TLX) to measure their ultrasound competency and perceived workload, respectively.ResultsTwenty-seven ultrasound novices were randomly allocated into 3 groups. The median skill test score of TE, CE, and SL was 22 [interquartile range (IQR): 18–28], 24 [IQR: 21–31], and 16 [IQR: 15–18], respectively (p < 0.01). Pairwise comparisons of median test scores of 3 groups demonstrated a statistical significance in comparisons of TE vs. SL (22 vs. 16, p = 0.01) and CE vs. SL (24 vs. 16, p < 0.01), but not in TE vs. CE (22 vs. 24, p = 0.56). There was no statistical significance observed in the median NASA-TLX scores among the 3 groups; 54 [IQR:47–61] in TE, 57 [IQR:22–64] in CE, and 66 [IQR: 66–72] in SL (p = 0.05).ConclusionsOur tele-education model was more effective than self-directed learning. There was no statistically significant difference in effectiveness between the tele-education and the conventional education groups. Importantly, tele-education did not impose a significantly higher workload on learners compared to conventional education or self-directed learning. Tele-education has a substantial potential as an alternative to conventional ultrasound training.

Design and Implementation of Virtualization Cloud Computing System Intelligent Terminal Application Layer

Cloud task scheduling has become a trend, and the shortcomings of traditional scheduling algorithms can be optimized through mathematical models of other cloud task scheduling scenarios. In order to improve the virtualization data processing effect of intelligent terminal application layer, this paper proposes an improved krill swarm optimization algorithm based on adaptive weight. The optimization of cluster load balancing and task average response time ratio are used to improve the convergence and accuracy of task scheduling algorithm. Moreover, this paper uses CloudSim simulation tool to conduct experiments to verify the effectiveness of the proposed model. In addition, this paper proposes an application-based virtualization method, which virtualizes the application programs inside the host machine into the virtualization software inside the virtual machine, so that the virtual machine can access it. Finally, this paper verifies the reliability of the proposed method with experiments, thus providing a theoretical reference for the subsequent design of intelligent terminal application layer virtualization cloud computing system. Compared with the traditional way of using physical hardware, using virtual machine hardware is more flexible, efficient and safe, which brings great convenience to the development and deployment of applications.

Feasibility of Using Wearable Sensors to Measure Listening-Related Stress

Purpose: This study evaluated the feasibility of using wearable sensors to assess listening-related stress in varying listening difficulties. The results were compared to listening effort assessed using laboratory-grade physiological measures. We hypothesized that these wearable sensors could accurately measure listening-related stress and that the results would be in the same direction as those observed with laboratory-grade equipment. Method: A within-subject repeated-measures study was conducted on 16 young adults with typical hearing ability. Participants wore three commercially available sensors to record heart rate (HR), respiration rate (RR), and galvanic skin response (GSR). Participants' listening-related stress was assessed using self-report, wearable sensors, and laboratory-grade physiological measures while listening to sentences in noise. Listening conditions were manipulated in terms of signal-to-noise ratios (SNRs; −4, 0, +4, and +8 dB SNR), sentence predictability (high and low), and stress-inducing negative feedback (flash of light and monetary punishers). Results: On average, participants reported higher arousal and task load with decreasing SNR, for low predictability, and with negative feedback. Participants had significantly higher HR and RR in difficult listening conditions, when measured with wearable sensors. However, no significant differences were observed for skin conductance. There was a good agreement between the measures for HR but not for RR and GSR. Conclusions: Although wearable sensors have potential in reflecting changes in listening effort, the results were not consistent with laboratory-grade measures. Methodological choices in both measures and design appear to affect outcomes. Future studies should focus on crafting designs appropriate to wearable devices to reflect changes in listening-related stress.

Adaptive Privacy-Preserving Coded Computing with Hierarchical Task Partitioning.

Coded computing is recognized as a promising solution to address the privacy leakage problem and the straggling effect in distributed computing. This technique leverages coding theory to recover computation tasks using results from a subset of workers. In this paper, we propose the adaptive privacy-preserving coded computing (APCC) strategy, designed to be applicable to various types of computation tasks, including polynomial and non-polynomial functions, and to adaptively provide accurate or approximated results. We prove the optimality of APCC in terms of encoding rate, defined as the ratio between the computation loads of tasks before and after encoding, based on the optimal recovery threshold of Lagrange Coded Computing. We demonstrate that APCC guarantees information-theoretical data privacy preservation. Mitigation of the straggling effect in APCC is achieved through hierarchical task partitioning and task cancellation, which further reduces computation delays by enabling straggling workers to return partial results of assigned tasks, compared to conventional coded computing strategies. The hierarchical task partitioning problems are formulated as mixed-integer nonlinear programming (MINLP) problems with the objective of minimizing task completion delay. We propose a low-complexity maximum value descent (MVD) algorithm to optimally solve these problems. The simulation results show that APCC can reduce the task completion delay by a range of 20.3% to 47.5% when compared to other state-of-the-art benchmarks.

Distractor filtering and task load in working memory training in healthy older adults.

Filtering efficiency (FE) has been suggested as a task-related process of working memory (WM) in older adults, but the interaction of distractors with WM when implemented as a training to improve WM capacity is unclear. To investigate the effect of manipulations of WM and/or FE load in a multicomponent model-based WM training in improving WM capacity. 205 healthy older adults (129 women; aged 64.0 ± 8.3 years) were randomised into three WM training groups with manipulations of WM and FE load (high WM; low FE load, high WM; high FE load and low WM; high FE load). All groups underwent three online cognitive testing sessions and twelve 40-min training sessions over three weeks using the SmartBrain smartphone application. WM capacity was measured with complex span tasks and FE using the Change Detection Task. Linear mixed-effect models adjusted for age, sex, education and pre-baseline performance showed increased WM capacity post-training, but no difference between groups. While both distractors and WM are needed to improve WM in the absence of distraction, manipulations of the FE and WM load do not influence improvements following training.

In-depth analysis of fault tolerant approaches integrated with load balancing and task scheduling

In-depth analysis of fault tolerant approaches integrated with load balancing and task scheduling

A case study of the subjective workload of forest equipment operators in South Carolina

ABSTRACT Logging operations in the Southern United States have become more mechanized over time. However, extensive use of complex and heavy forest machineries for long durations increases operator workload, especially the cognitive demand. Working under demanding conditions can decrease the health of forest equipment operators over time, reducing productivity and increasing the risk of accidents. This study provides an initial assessment of the workload of logging equipment operators during timber harvesting operations using conventional wheeled feller-buncher, grapple skidder, and knuckle-boom loader harvesting systems by assessing the subjective workload of the logging equipment operators in South Carolina. In addition, we observed the heart rate of equipment operators to study the activities causing excessive physical and mental workload. Logging equipment operators self-evaluated their workload using the NASA Task Load Index, a subjective measure of workload. Results show no significant difference in the overall workload of equipment operators working at clearcut and thinning sites. The workload dimensions of Effort and Frustration contributed the most to the overall workload, while Performance had the least contribution. Sudden heart rate spikes occurred when operators conducted physical activities such as clearing debris from a felling head but were otherwise unobserved.

Investigating mental workload across task modalities: a multimodal analysis using pupillometry

Understanding mental workload is challenging due to its multidimensional nature and varying sensitivities of its primary measures: task performance, perceived workload, and physiological responses. This study investigates the effects of task load on performance, perceived workload, and pupil measures across different information modalities. A within-subjects experiment involving three tasks (digit span, matrix span, and dual n-back) was conducted with three task load levels. Workload measures included accuracy/sensitivity, reaction time, NASA-TLX, peak pupil diameter, and peak pupil latency. Consistent patterns of associations between task load and these workload measures were found across the three modalities. Workload measures revealed a nuanced interplay between task modality and task load. Robustness of peak pupil latency, accuracy, and NASA-TLX was highlighted across verbal and visual modalities, while peak pupil diameter showed a weaker impact with differences between modalities. The findings encourage multivariate assessment of mental workload to account for different task modalities.

Using multivariate partial least squares on fNIRS data to examine load-dependent brain-behaviour relationships in aging.

Researchers implementing non-invasive neuroimaging have reported distinct load-dependent brain activity patterns in older adults compared with younger adults. Although findings are mixed, these age-related patterns are often associated with compensatory mechanisms of cognitive decline even in the absence of direct comparisons between brain activity and cognitive performance. This study investigated the effects of cognitive load on brain-behavior relationships in younger and older adults using a data-driven, multivariate partial least squares (PLS) analysis of functional near-infrared spectroscopy (fNIRS) data. We measured bilateral prefrontal brain activity in 31 older and 27 younger adults while they performed single and dual 2-back tasks. Behavioral PLS analysis was used to determine relationships between performance metrics (reaction time and error rate) and brain oxygenation (HbO) and deoxygenation (HbR) patterns across groups and task loads. Results revealed significant age-group differences in brain-behavior relationships. In younger adults, increased brain activity (i.e., increased HbO and decreased HbR) was associated with faster reaction times and better accuracy in the single task, indicating sufficient neural capacity. Conversely, older adults showed a negative correlation between HbR and error rates in the single task; however, in the dual task, they demonstrated a positive relationship between HbO and performance, indicative of compensatory mechanisms under the higher cognitive load. Overall, older adults' showed relationships with either HbR or HbO, but not both, indicating that the robustness of the relationship between brain activity and behavior varies across task load conditions. Our PLS approach revealed distinct load-dependent brain activity between age groups, providing further insight into neurocognitive aging patterns, such as compensatory mechanisms, by emphasizing the variability and complexity of brain-behavior relationships. Our findings also highlight the importance of considering task complexity and cognitive demands in interpreting age-related brain activity patterns.

An Exploratory Study of the Impact of Task Selection Strategies on Worker Performance in Crowdsourcing Microtasks

In microtask crowdsourcing systems like Amazon Mechanical Turk (AMT) and Appen Figure-Eight, workers often employ task selection strategies, completing sequences of tasks to maximize earnings. While previous literature has explored the effects of sequential tasks with varying complexities of the same type, there is a lack of knowledge on the consequences when multiple types of tasks with similar levels of difficulty are performed. This study examines the impact of sequences of three frequently employed task types, namely image classification, text classification, and surveys, on workers' engagement, accuracy, and perceived workloads. In addition, we analyze the influence of workers' personality traits on their strategies for selecting tasks. Our study, which involved 558 participants using AMT, found that engaging in sequences of distinct task types had a detrimental effect on classification task engagement and accuracy. It also increases the perceived task load and the worker's frustration. Nevertheless, the precise order of tasks does not significantly impact these results. Moreover, we showed a slight association between personality traits and the workers' selection strategy for the tasks. The results offered valuable knowledge for designing an efficient and inclusive crowdsourcing platform.

Speech-mediated manipulation of da Vinci surgical system for continuous surgical flow

AbstractWith the advent of robot-assisted surgery, user-friendly technologies have been applied to the da Vinci surgical system (dVSS), and their efficacy has been validated in worldwide surgical fields. However, further improvements are required to the traditional manipulation methods, which cannot control an endoscope and surgical instruments simultaneously. This study proposes a speech recognition control interface (SRCI) for controlling the endoscope via speech commands while manipulating surgical instruments to replace the traditional method. The usability-focused comparisons of the newly proposed SRCI-based and the traditional manipulation method were conducted based on ISO 9241-11. 20 surgeons and 18 novices evaluated both manipulation methods through the line tracking task (LTT) and sea spike pod task (SSPT). After the tasks, they responded to the globally reliable questionnaires: after-scenario questionnaire (ASQ), system usability scale (SUS), and NASA task load index (TLX). The completion times in the LTT and SSPT using the proposed method were 44.72% and 26.59% respectively less than the traditional method, which shows statistically significant differences (p &lt; 0.001). The overall results of ASQ, SUS, and NASA TLX were positive for the proposed method, especially substantial reductions in the workloads such as physical demands and efforts (p &lt; 0.05). The proposed speech-mediated method can be a candidate suitable for the simultaneous manipulation of an endoscope and surgical instruments in dVSS-used robotic surgery. Therefore, it can replace the traditional method when controlling the endoscope while manipulating the surgical instruments, which contributes to enabling the continuous surgical flow in operations consequentially.

Effects of simulated driving task screen background color combinations on visual performance and visual fatigue

ABSTRACT In-car smart devices, such as touchscreen control systems, internet interfaces and hands-free phone functions can cause problems affecting driver comfort, visual fatigue and performance, resulting in decreased reaction times, increasing the likelihood of accidents. This study utilizes a touchscreen display and driving simulator as the operational tools in experiments designed to investigate how changes in screen brightness and different color combinations affect the visual performance and the level of visual fatigue of the driver. Specifically, the aim is to explore the impact of changes in brightness and color combinations on visual fatigue and whether there are interactions between them. During the experimental process, relevant data, including the Critical Fusion Frequency (CFF), touchscreen offset, and the NASA Task Load Index (NASA-TLX), are collected and then analyzed using the SPSS statistical software to provide objective and reliable supporting data and valuable insights to related research fields. The experimental results show that the environmental illumination significantly affects the touchscreen offset, CFF and the NASA-TLX), while the color combination significantly affects touchscreen offset (movement and rotation) and the NASA-TLX.

Electromyographically controlled prosthetic wrist improves dexterity and reduces compensatory movements without added cognitive load

Wrist function is a top priority for transradial amputees. However, the combined functional, biomechanical, and cognitive impact of using a powered prosthetic wrist is unclear. Here, we quantify task performance, compensatory movements, and cognitive load while three transradial amputees performed a modified Clothespin Relocation Task using two myoelectric prostheses with and without the wrists. The two myoelectric prostheses include a commercial prosthesis with a built-in powered wrist, and a newly developed inexpensive prosthetic wrist for research purposes, called the “Utah wrist”, that can be adapted to work with various sockets and prostheses. For these three participants, task failure rate decreased significantly from 66% ± 12% without the wrist to 39% ± 9% with the Utah wrist. Compensatory forward leaning movements also decreased significantly, from 24.2° ± 2.5 without the wrist to 12.6° ± 1.0 with the Utah wrist, and from 23.6° ± 7.6 to 15.3° ± 7.2 with the commercial prosthesis with an integrated wrist. Compensatory leftward bending movements also significantly decreased, from 20.8° ± 8.6 to 12.3° ± 5.3, for the commercial with an integrated wrist. Importantly, simultaneous myoelectric control of either prosthetic wrist had no significant impact on cognitive load, as assessed by the NASA Task Load Index survey and a secondary detection response task. This work suggests that functional prosthetic wrists can improve dexterity and reduce compensation without significantly increasing cognitive effort. These results, and the introduction of a new inexpensive prosthetic wrist for research purposes, can aid future research and development and guide the prescription of upper-limb prostheses.

Robotic-Assisted Navigation in Single-Level Transforaminal Lumbar Interbody Fusion Reduces Surgeons’ Mental Workload Compared With Fluoroscopic and Computed Tomographic Techniques: A Nonrandomized Prospective Controlled Trial

Background: Pedicle screw placement during spine fusion is physically and mentally demanding for surgeons. Consequently, spine surgeons can become fatigued, which has implications for both patient safety and surgeon well-being. Purpose: We sought to assess the cognitive workload of surgeons placing pedicle screws using robotic-assisted navigation compared with fluoroscopic and computed tomography (CT)-assisted placement. Methods: We performed a nonrandomized prospective controlled trial to compare the cognitive workload of 3 surgeons performing single-level minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) using robotic, CT, or fluoroscopic navigation on 25 patients (15 in the robotic navigation group and 10 in the nonrobotic group). Immediately after each procedure, surgeons submitted the National Aeronautics and Space Administration–Task Load Index (NASA-TLX), which has 6 subscales: mental demands, physical demands, temporal demands, performance, effort, and frustration. Four tasks associated with pedicle screw placement were assessed independently: (1) screw planning, (2) calibrating robot/obtaining imaging/registration, (3) pedicle cannulation, and (4) screw placement. Patient demographics and surgical characteristics were obtained and reviewed. Results: Surgeons’ self-reported cognitive workload was significantly reduced when using robotic-assisted navigation versus CT/fluoroscopic navigation. Workload was reduced for screw planning, pedicle cannulation, and screw placement. In addition, there were significant reductions in each subdomain for these 3 tasks, encompassing mental demand, physical demand, temporal demand, effort, and frustration with improved task performance. Conclusions: This study found significant reductions in mental workload with improved perceived performance for robotic-assisted pedicle screw placement compared with fluoroscopic and CT-navigation techniques. Lowering the cognitive burden associated with screw placement may allow surgeons to address the remainder of the operative case with less decision fatigue, prevent complications, and increase surgeon wellness.

Dynamic Modelling of the Spine for the Estimation of Vertebral Joint Torques using Gordon’s Method

World Health Organization (WHO) recognised musculoskeletal disorder (MSD) as the main contributor to disability worldwide, with low back pain as the major disorder globally. The occupational disorder normally occurs during lifting. The weight of the load and manual handling tasks during lifting has an impact on the spine and joint torque. The purpose of this study is to propose a dynamic model of the spine that can estimate the vertebral joint torques. This study is a bimodal approach that consists of the experimental and theoretical parts. Ten healthy UniMAP students (10 males) participated in this study. The subjects were required to lift a 3kg weight plate for kinematics and EMG data collection. Retro-reflective markers were attached to the subject body, and then, the data was collected and stored in QTM software. Kinematic data was processed using C-Motion Visual3D. Eight Trigno Wireless Sensors were attached on the back muscles (left and right erector spinae, latissimus dorsi, external oblique and internal oblique). The EMG data were stored in EMG Acquisition software and subsequently, were processed using EMG Analysis software. Gordon’s method was used to develop a mathematical model of the spine. The model comprises of five kinematic chains which connected three lumbar, two thoracic and one cervical. The model calculated the value of joint torque on flexion/extension movement using Matlab and Microsoft Excel. When calculated on L5, the model gives an estimation within 0 – 30 kgm2s-2. The model was further used to estimate value of L3, L1, MAI and T2. The estimate average value of joint torque at L3 is within 5 – 25 kgm2s-2, MAI is within 0 – 6 kgm2s-2 and T2 is within 0 – 1 kgm2s-2. The average RMS values show the highest muscle activity on the right internal oblique muscle (1519 µV), followed by the right external oblique (1166 µV) and left external oblique (418 µV). The results obtained gives an insight on the value of joint torque that have been applied by the spine and the most activated back muscles during lifting.

Abdominal Drawing-In Maneuver is Less Effective for Core Stability During High Load Tasks: A Systematic Review

Context: The abdominal drawing-in maneuver (ADIM) is a technique commonly used to activate deep core muscles for the prevention and rehabilitation of low back pain. However, its benefits during high-load tasks (HLT) are unclear. Objectives: The primary objective of this article is to review the literature to determine whether the use of ADIM enhances core stabilization during HLT. Additionally, we will examine if other factors, beyond load, could influence the effectiveness of this activation maneuver. Methods: A search was conducted using PubMed databases for studies that compared interventions using ADIM to those without ADIM. The literature search spanned from January 1981 to March 2024. Only studies that included kinematic assessments were selected. Results: The search yielded 359 studies, of which 24 were included in the final analysis. Task load was analyzed based on Mottram and Comerford's criteria, alongside other approaches such as the source of the perturbation applied to the subject and body position. In conditions using ADIM, better performance was observed in only 16.66% of interventions with HLT, whereas other conditions (OC) without ADIM performed better in 83.33% of interventions using HLT. When core stability was tested against external perturbations, ADIM was less effective in all scenarios. In lying positions, ADIM performed better in 4 tasks, while OC performed better in 2. In upright positions, ADIM was more effective in 7 tasks, while OC performed better in 6. Conclusions: The findings suggest that ADIM should not be used if the goal is to train core stability and strength during HLT. Abdominal drawing-in maneuver was less effective for stabilizing the core during tasks involving external perturbations, and its use was also less effective in upright positions.

A Multiparametric Acoustic and Self-Perceptual Measure of Laryngeal Hydrations in Speech-Language Pathologists: A Preliminary Longitudinal Investigation

PurposeSpeech-language pathologists (SLPs) work with individuals with communication disorders. Their work can strain their voice, resulting in dysphonia, adversely affecting their career and quality of life. Laryngeal hydration can prevent vocal damage and improve vocal performance in SLPs. However, there is limited research on the effects of laryngeal hydration in SLPs using longitudinal studies. Hence, the present study aims to assess the longitudinal impact of laryngeal hydration in SLPs using multiparametric acoustic and self-perceptual measures. MethodThe research method lasted for six consecutive days, with each day lasting 2-3 hours for each participant. Ten SLPs, aged 18-30 years, were recruited. On alternate days, laryngeal hydration treatment (Systemic, surface, and combined hydration) was given while participants performed vocal loading tasks. Pre- and post-recordings of the Acoustic Voice Quality Index (AVQI) and its consistent parameters (CPPs, HNR, shimmer%, shimmer local, LTAS slope, LTAS Tilt) and self-perceptual measures [Perceived Phonatory Effort (PPE), Perceived Vocal Tiredness (PVT)] were taken. Kruskal-Wallis Test and the Wilcoxon Signed Rank Test were used to assess vocal changes in SLPs with laryngeal hydration. ResultsNo significant differences in overall AVQI scores were found between pre and post-tests for all types of laryngeal hydration treatment. However, there was a significant increase in CPPs and the LTAS slope for combined hydration and a decrease in HNR with an increase in shimmer local for systemic hydration in the post-test compared to the pre-test. Only systemic hydration in the post-test showed a rise in PPE and PVT compared to the pre-test, compared to surface and combined hydration. ConclusionVoice outcome measures of the present study demonstrated the immediate beneficial effects of surface hydration and combined hydration in SLPs by preserving voice quality during vocal loading. Systemic hydration had less of an immediate impact on voice quality. This study suggests empirical evidence for laryngeal hydration, which can enhance vocal performance and preserve voice quality in SLPs.

Muscle Synergy Differences During A Single-limb Loading Task Following Anterior Cruciate Ligament Reconstruction

Muscle Synergy Differences During A Single-limb Loading Task Following Anterior Cruciate Ligament Reconstruction

Augmented reality visualization for ultrasound-guided interventions: a pilot randomized crossover trial to assess trainee performance and cognitive load

BackgroundAugmented reality (AR) technology involving head-mounted displays (HMD) represents a significant innovation in medical education, particularly for training in guided invasive procedures. Novice physicians often face challenges in simultaneously identifying anatomical landmarks and performing procedures when learning point-of-care ultrasound (POCUS). Our primary objective was to determine the effectiveness of AR in enhancing physician training for ultrasound-guided interventions using AR visual overlays. The secondary objective was to compare cognitive load between traditional ultrasound training settings and AR-assisted training settings.MethodsThis randomized crossover study, conducted from 2021 to 2022, compared performance and cognitive load of trainees attempting accurate central venous catheter (CVC) placement using an AR-HMD to display ultrasound images (AR-US), compared with standard ultrasound without visual overlay (S-US). We enrolled 47 trainees, including 22 final-year undergraduate medical students and 25 postgraduate physicians (years 1–4) from three hospitals in Taiwan. All participants had basic training in US-guided CVC placement but lacked AR-US experience. Performance and cognitive load were assessed using time measurements and NASA Task Load Index (NASA-TLX), covering the dimensions of Mental-, Physical- and Temporal Demand, and Performance, Effort and Frustration.ResultsWe found AR technology reduced the time required for critical steps in CVC placement, while minimizing users’ neck strain. Female and junior trainees using AR-US identified anatomy and localized veins faster than those using S-US. Using AR-US, female trainees significantly outperformed males in anatomical identification [mean difference (MD): -10.79 s (95% CI: -2.37 to -19.21)]. The NASA-TLX cognitive load assessment showed mental workload trending lower in all dimensions except performance while using AR-US, compared to S-US. Similarly, junior trainees’ effort- and frustration scores were lower [MD: -2.73 (95% CI: -5.04 to -0.41) and -2.41 (95% CI: -4.51 to -0.31), respectively], as were female trainees’ effort scores [MD: -3.07 (95% CI: -6.10 to -0.03)] when using AR-US, compared to S-US, whereby these differences were statistically significant.ConclusionsAR technology helped improve trainee performance and reduced cognitive load during ultrasound-guided CVC placement. These findings support the application of AR technology to enhance physician training in ultrasound-guided interventional procedures, suggesting that AR-HMDs could be a valuable tool in medical education.Trial registrationThe trial was registered with Clinicaltrials.gov on 20/09/2023 as a clinical trial, under the identifier NCT 06055400.