Eye Tracking to Evaluate the Effects of Interruptions and Workload in a Complex Task

Author(s):  
Dina Kanaan ◽  
Nadine Marie Moacdieh

Objective To use eye tracking to understand the effects of interruptions in different workload conditions as part of a monitoring and change detection task. Background Interruptions are detrimental to performance in complex, multitasking domains. There is a need for better display design techniques that help users overcome interruptions regardless of their workload level. This requires understanding a user’s attentional state immediately after an interruption in order to determine what type of display adjustments are most suitable. Method An emergency dispatching simulator was developed with a visual primary task and auditory interruptive task. Two levels of workload were induced by varying the number of emergency vehicles to monitor for changes and the rate of changes to monitor. Eye tracking, performance, and subjective measures (NASA-Task Load Index) were collected and analyzed for 41 participants. Results As expected, high workload interacted with interruptions to further degrade primary task performance and alter participants’ attention allocation immediately after the interruption. Participants in the high workload condition had more narrowed, slower scan patterns immediately after the interruption as compared to before the interruption, as evidenced by lower scanpath length per second and mean saccade amplitude. However, this change was not observed in low workload. Conclusion High workload modulates the effects of interruptions on performance and eye movements. Users in the high workload condition struggle to quickly scan the display in the seconds following an interruption. Application The results can provide insight into the type of display adjustments needed right after an interruption in a high-workload environment.

2020 ◽  
Vol 14 (2) ◽  
pp. 132-151
Author(s):  
Nadine Marie Moacdieh ◽  
Shannon P. Devlin ◽  
Hussein Jundi ◽  
Sara Lu Riggs

High mental workload, in addition to changes in workload, can negatively affect operators, but it is not clear how sudden versus gradual workload transitions influence performance and visual attention allocation. This knowledge is important as sudden shifts in workload are common in multitasking domains. The objective of this study was to investigate, using performance and eye tracking metrics, how constant versus variable levels of workload affect operators in the context of a dual-task paradigm. An unmanned aerial vehicle command and control simulation varied task load between low, high, gradually transitioning from low to high, and suddenly transitioning from low to high. Performance on a primary and secondary task and several eye tracking measures were calculated. There was no significant difference between sudden and gradual workload transitions in terms of performance or attention allocation overall; however, both sudden and gradual workload transitions changed participants’ strategy in dealing with the primary and secondary task as compared to low/high workload. Also, eye tracking metrics that are not frequently used, such as transition rate and stationary entropy, provided more insight into performance differences. These metrics can potentially be used to better understand operators’ strategies and could form the basis of an adaptive display.


Author(s):  
Joseph K. Nuamah ◽  
Younho Seong

Psychophysiological measures can be used to determine whether a particular display produces a general difference in brain function. Such information might be valuable in efforts to improve usability in display design. In this preliminary study, we aimed to use the electroencephalography (EEG) task load index (TLI), given by the ratio of mean frontal midline theta energy to mean parietal alpha energy, to provide insight into the mental effort required by participants performing intuition-inducing and analysis-inducing tasks. We employed behavioral measures (reaction time and percent correct), and a subjective measure (NASA-Task Load Index) to validate the objective measure (TLI). The results we obtained were consistent with our hypothesis that mental effort required for analysis-inducing tasks would be different from that required for intuition-inducing tasks. Although our sample size was small, we were able to obtain a significant positive correlation between NASA-Task Load Index and TLI.


2016 ◽  
Vol 14 (4) ◽  
pp. 289 ◽  
Author(s):  
Erik G. Prytz, PhD ◽  
Jonas Rybing, MSc ◽  
Carl-Oscar Jonson, PhD

Objective: This study reports on an initial test using a validated workload measurement method, the NASA Task Load Index (TLX), as an indicator of joint emergency exercise effectiveness. Prior research on emergency exercises indicates that exercises must be challenging, ie, result in high workload, to be effective. However, this is often problematic with some participants being underloaded and some overloaded. The NASA TLX was used to test for differences in workload between commanders and subordinates and among three different emergency response organizations during a joint emergency exercise.Design: Questionnaire-based evaluation with professional emergency responders.Setting: The study was performed in conjunction with a large-scale interorganizational joint emergency exercise in Sweden.Participants: A total of 20 participants from the rescue services, 12 from the emergency medical services, and 12 from the police participated in the study (N = 44). Ten participants had a command-level role during the exercise and the remaining 34 were subordinates.Main Outcome Measure(s): The main outcome measures were the workload subscales of the NASA TLX: mental demands, physical demands, temporal demands, performance, effort, and frustration. Results: The results showed that the organizations experienced different levels of workload, that the commanders experienced a higher workload than the subordinates, and that two out of three organizations fell below the twenty-fifth percentile of average workload scores compiled from 237 prior studies.Conclusions: The results support the notion that the NASA TLX could be a useful complementary tool to evaluate exercise designs and outcomes. This should be further explored and verified in additional studies.


2002 ◽  
Vol 95 (1) ◽  
pp. 27-46 ◽  
Author(s):  
Sean Reilley ◽  
Anthony F. Grasha ◽  
John Schafer

The relationships among workload, stress, and performance efficiency are topics of applied interest and theoretical importance to researchers concerned with human performance. Such interest extends to a variety of occupational areas including inpatient, outpatient, and community pharmacies. In that context, these relationships have become a consumer health issue given concerns that workload contributes to job stress and a significant decline in dispensing accuracy. In the present study, 102 trained college-aged individuals evaluated simulated pharmacy prescriptions for errors under conditions of either low workload (72 orders over 120 min. on task) or high workload (120 orders over 120 min. on task) in a high-fidelity simulated pharmacy environment. Overall, cumulative and detection theory indices of error detection were compatible with estimates from pharmacy field studies. When rates of sensitivity and specificity for detection were examined, substantial variations in the identification of errors (sensitivity) and difficulties with detection of data-entry mistakes were observed in the high workload condition, but only modest effects emerged for the low workload condition. Although increases in objective workload were associated with modest declines in detection accuracy, objective workload did nor significantly affect negative mood (Mood Adjective Checklist) or perceived workload (NASA-Task Load Index) as expected.


Author(s):  
Arun Sivananthan ◽  
Alexandros Kogkas ◽  
Ben Glover ◽  
Ara Darzi ◽  
George Mylonas ◽  
...  

Abstract Background Interventional endoluminal therapy is rapidly advancing as a minimally invasive surgical technique. The expanding remit of endoscopic therapy necessitates precision control. Eye tracking is an emerging technology which allows intuitive control of devices. This was a feasibility study to establish if a novel eye gaze-controlled endoscopic system could be used to intuitively control an endoscope. Methods An eye gaze-control system consisting of eye tracking glasses, specialist cameras and a joystick was used to control a robotically driven endoscope allowing steering, advancement, withdrawal and retroflexion. Eight experienced and eight non-endoscopists used both the eye gaze system and a conventional endoscope to identify ten targets in two simulated environments: a sphere and an upper gastrointestinal (UGI) model. Completion of tasks was timed. Subjective feedback was collected from each participant on task load (NASA Task Load Index) and acceptance of technology (Van der Laan scale). Results When using gaze-control endoscopy, non-endoscopists were significantly quicker when using gaze-control rather than conventional endoscopy (sphere task 3:54 ± 1:17 vs. 9:05 ± 5:40 min, p = 0.012, and UGI model task 1:59 ± 0:24 vs 3:45 ± 0:53 min, p < .001). Non-endoscopists reported significantly higher NASA-TLX workload total scores using conventional endoscopy versus gaze-control (80.6 ± 11.3 vs 22.5 ± 13.8, p < .001). Endoscopists reported significantly higher total NASA-TLX workload scores using gaze control versus conventional endoscopy (54.2 ± 16 vs 26.9 ± 15.3, p = 0.012). All subjects reported that the gaze-control had positive ‘usefulness’ and ‘satisfaction’ score of 0.56 ± 0.83 and 1.43 ± 0.51 respectively. Conclusions The novel eye gaze-control system was significantly quicker to use and subjectively lower in workload when used by non-endoscopists. Further work is needed to see if this would translate into a shallower learning curve to proficiency versus conventional endoscopy. The eye gaze-control system appears feasible as an intuitive endoscope control system. Hybrid gaze and hand control may prove a beneficial technology to evolving endoscopic platforms.


Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S209-S221
Author(s):  
Lu Han ◽  
Hechen Zhang ◽  
Zhongxia Xiang ◽  
Jinze Shang ◽  
Shabila Anjani ◽  
...  

BACKGROUND: The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes. OBJECTIVE: The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment. METHODS: An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively. RESULTS: Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort. CONCLUSION: The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen.


Author(s):  
Ahmed Ezzat ◽  
Alexandros Kogkas ◽  
Josephine Holt ◽  
Rudrik Thakkar ◽  
Ara Darzi ◽  
...  

Abstract Background Within surgery, assistive robotic devices (ARD) have reported improved patient outcomes. ARD can offer the surgical team a “third hand” to perform wider tasks and more degrees of motion in comparison with conventional laparoscopy. We test an eye-tracking based robotic scrub nurse (RSN) in a simulated operating room based on a novel real-time framework for theatre-wide 3D gaze localization in a mobile fashion. Methods Surgeons performed segmental resection of pig colon and handsewn end-to-end anastomosis while wearing eye-tracking glasses (ETG) assisted by distributed RGB-D motion sensors. To select instruments, surgeons (ST) fixed their gaze on a screen, initiating the RSN to pick up and transfer the item. Comparison was made between the task with the assistance of a human scrub nurse (HSNt) versus the task with the assistance of robotic and human scrub nurse (R&HSNt). Task load (NASA-TLX), technology acceptance (Van der Laan’s), metric data on performance and team communication were measured. Results Overall, 10 ST participated. NASA-TLX feedback for ST on HSNt vs R&HSNt usage revealed no significant difference in mental, physical or temporal demands and no change in task performance. ST reported significantly higher frustration score with R&HSNt. Van der Laan’s scores showed positive usefulness and satisfaction scores in using the RSN. No significant difference in operating time was observed. Conclusions We report initial findings of our eye-tracking based RSN. This enables mobile, unrestricted hands-free human–robot interaction intra-operatively. Importantly, this platform is deemed non-inferior to HSNt and accepted by ST and HSN test users.


2017 ◽  
Vol 5 (1) ◽  
pp. 148-159 ◽  
Author(s):  
Louisa D. Raisbeck ◽  
Jed A. Diekfuss

Performance benefits exist for an external focus of attention compared with an internal focus of attention for performance and learning (Wulf, 2013). It is unknown, however, if varying the number of verbal cues affects learning and performance. Focus of attention and the number of verbal cues were manipulated during a simulated handgun-shooting task. For the internal focus conditions, participants were told to focus on their hand, arm, and wrist, whereas the external focus instructions were to focus on the gun, gun barrel, and gun stock. To manipulate the number of verbal cues, participants received instruction to focus on a single verbal cue or multiple verbal cues. Shooting performance was assessed at baseline, acquisition, and at two separate retention phases (immediate, delayed) that included transfer tests. Participants completed the NASA—Task Load Index to assess workload following all trials. Participants who received one verbal cue performed significantly better during immediate retention than those who received three verbal cues. Participants who used external focus of attention instructions had higher performance and reported less workload at delayed retention compared to those who used internal focus instructions. This research provides further support for the benefits of an external focus and highlights the importance of minimizing the number of verbal cues.


Author(s):  
Cindy Chamberland ◽  
Helen M. Hodgetts ◽  
Benoît R. Vallières ◽  
François Vachon ◽  
Sébastien Tremblay

Dynamic and complex command and control situations often require the timely recognition of changes in the environment in order to detect potentially malicious actions. Change detection can be challenging within a continually evolving scene, and particularly under multitasking conditions whereby attention is necessarily divided between several subtasks. On-screen tools can assist with detection (e.g., providing a visual record of changes, ensuring that none are overlooked), however, in a high workload environment, this may result in information overload to the detriment of the primary task. One alternative is to exploit the auditory modality as a means to support visual change detection. In the current study, we use a naval air-warfare simulation, and introduce an auditory alarm to coincide with critical visual changes (in aircraft speed/direction) on the radar. We found that participants detected a greater percentage of visual changes and were significantly quicker to detect these changes when they were accompanied by an auditory alarm than when they were not. Furthermore, participants reported that mental demand was lower in the auditory alarm condition, and this was reflected in reduced classification omissions on the primary task. Results are discussed in relation to Wickens’ multiple resource theory of attention and indicate the potential for using the auditory modality to facilitate visual change detection.


2021 ◽  
Author(s):  
Taiwo Amida

The majority of Unmanned Aerial Vehicle (UAV) accidents can be directly related to human error. For this reason, standards and guidelines focusing on human factors have been published by various organizations such as Transport Canada, FAA, EASA, NASA and military agencies. The objective of this thesis is to present a methodology for designing a Ground Control Station (GCS) using available standards and guidelines for human factors. During the design process, a detailed analysis was performed using human factors methods to ensure all requirements were met; each phase of the design follows the guidelines presented in the compiled human factors standards and guidelines. The GCS interface was developed using advanced programming techniques and commercial off-the-shelf software. Moreover, an operator workload evaluation was carried out using NASA task load index for validation of design methodology. It was found that the applied methodology not only improved the pilot workload, but also ensured that all user and stakeholders’ requirements are met.


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