Workload Assessment of Operators: Correlation Between NASA-TLX and Pupillary Responses

Operators in high-stress environments often face significant cognitive demands that can impair their performance, underscoring the need for comprehensive workload assessment. This study aims to study the relationship between subjective self-reported measures, the NASA task load index (NASA-TLX), obj...

Full description

Saved in:
Bibliographic Details
Main Authors: Yun Wu, Yao Zhang, Bin Zheng
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Applied Sciences
Subjects:
Online Access:https://www.mdpi.com/2076-3417/14/24/11975
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850042515969802240
author Yun Wu
Yao Zhang
Bin Zheng
author_facet Yun Wu
Yao Zhang
Bin Zheng
author_sort Yun Wu
collection DOAJ
description Operators in high-stress environments often face significant cognitive demands that can impair their performance, underscoring the need for comprehensive workload assessment. This study aims to study the relationship between subjective self-reported measures, the NASA task load index (NASA-TLX), objective bio-signal measures, and pupillary responses. The participants engaged in either a visual tracking task or a laparoscopic visuomotor task while their eye movements were recorded using a Tobii Pro Nano eye tracker (Tobii Technology Inc., Stockholm, Sweden). Immediately after completing the tasks, participants provided NASA-TLX scores to assess their perceived workload. The study tested three hypotheses: first, whether increased pupil dilation correlates with higher NASA-TLX scores; second, whether task type affects workload; and third, whether task repetition influences workload. The results showed a moderate positive correlation between pupil size and NASA-TLX scores (r = 0.513, <i>p</i> < 0.001). The laparoscopic surgery task, which requires visuomotor coordination, resulted in significantly higher NASA-TLX scores (t = –6.23, <i>p</i> < 0.001), larger original pupil sizes (t = –22.57, <i>p</i> < 0.001), and more adjusted pupil sizes (t = –22.57, <i>p</i> < 0.001) than the purely visual task. Additionally, task repetition led to a significant reduction in the NASA-TLX scores (t = 2.86, <i>p</i> = 0.005), the original mean pupil size (t = 5.50, <i>p</i> < 0.001), and the adjusted pupil size (t = 6.34, <i>p</i> < 0.001). In conclusion, the study confirms a positive correlation between NASA-TLX scores and pupillary responses. Task type and repetition were found to influence workload and pupillary responses. The findings demonstrate the value of using both subjective and objective measures for workload assessments.
format Article
id doaj-art-d892546f0bca4e3998e92bdeff60f37f
institution DOAJ
issn 2076-3417
language English
publishDate 2024-12-01
publisher MDPI AG
record_format Article
series Applied Sciences
spelling doaj-art-d892546f0bca4e3998e92bdeff60f37f2025-08-20T02:55:31ZengMDPI AGApplied Sciences2076-34172024-12-0114241197510.3390/app142411975Workload Assessment of Operators: Correlation Between NASA-TLX and Pupillary ResponsesYun Wu0Yao Zhang1Bin Zheng2Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, CanadaDepartment of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, CanadaDepartment of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, CanadaOperators in high-stress environments often face significant cognitive demands that can impair their performance, underscoring the need for comprehensive workload assessment. This study aims to study the relationship between subjective self-reported measures, the NASA task load index (NASA-TLX), objective bio-signal measures, and pupillary responses. The participants engaged in either a visual tracking task or a laparoscopic visuomotor task while their eye movements were recorded using a Tobii Pro Nano eye tracker (Tobii Technology Inc., Stockholm, Sweden). Immediately after completing the tasks, participants provided NASA-TLX scores to assess their perceived workload. The study tested three hypotheses: first, whether increased pupil dilation correlates with higher NASA-TLX scores; second, whether task type affects workload; and third, whether task repetition influences workload. The results showed a moderate positive correlation between pupil size and NASA-TLX scores (r = 0.513, <i>p</i> < 0.001). The laparoscopic surgery task, which requires visuomotor coordination, resulted in significantly higher NASA-TLX scores (t = –6.23, <i>p</i> < 0.001), larger original pupil sizes (t = –22.57, <i>p</i> < 0.001), and more adjusted pupil sizes (t = –22.57, <i>p</i> < 0.001) than the purely visual task. Additionally, task repetition led to a significant reduction in the NASA-TLX scores (t = 2.86, <i>p</i> = 0.005), the original mean pupil size (t = 5.50, <i>p</i> < 0.001), and the adjusted pupil size (t = 6.34, <i>p</i> < 0.001). In conclusion, the study confirms a positive correlation between NASA-TLX scores and pupillary responses. Task type and repetition were found to influence workload and pupillary responses. The findings demonstrate the value of using both subjective and objective measures for workload assessments.https://www.mdpi.com/2076-3417/14/24/11975workload assessmentNASA-TLXpupillary responsesvisual-tracking tasklaparoscopic task
spellingShingle Yun Wu
Yao Zhang
Bin Zheng
Workload Assessment of Operators: Correlation Between NASA-TLX and Pupillary Responses
Applied Sciences
workload assessment
NASA-TLX
pupillary responses
visual-tracking task
laparoscopic task
title Workload Assessment of Operators: Correlation Between NASA-TLX and Pupillary Responses
title_full Workload Assessment of Operators: Correlation Between NASA-TLX and Pupillary Responses
title_fullStr Workload Assessment of Operators: Correlation Between NASA-TLX and Pupillary Responses
title_full_unstemmed Workload Assessment of Operators: Correlation Between NASA-TLX and Pupillary Responses
title_short Workload Assessment of Operators: Correlation Between NASA-TLX and Pupillary Responses
title_sort workload assessment of operators correlation between nasa tlx and pupillary responses
topic workload assessment
NASA-TLX
pupillary responses
visual-tracking task
laparoscopic task
url https://www.mdpi.com/2076-3417/14/24/11975
work_keys_str_mv AT yunwu workloadassessmentofoperatorscorrelationbetweennasatlxandpupillaryresponses
AT yaozhang workloadassessmentofoperatorscorrelationbetweennasatlxandpupillaryresponses
AT binzheng workloadassessmentofoperatorscorrelationbetweennasatlxandpupillaryresponses