Abstract Background Eye-movement metrics and subjective workload measures are extensively used to determine mental workload of participants. The aim of this study was to assess Electric overhead travelling (EOT) crane operators’ mental workload variability based on eye movement metrics such as fixation frequency, fixation duration, saccade duration, saccade amplitude, and fixation/saccade ratio during EOT crane operations in virtual reality (VR) based EOT crane simulator. Methods A 2k (k = 3) factorial experiment with factors namely, hazardous scenario, activity level, and trial was designed and conducted to demonstrate the proposed assessment approach. Throughout the experiment, we recorded the eye movements of 12 EOT crane operators of a steel industry of authors’ country. Post experiment, the National Aeronautics and Space Administration task load index (NASA-TLX) was adopted as a subjective workload measure and run time of task completion was recorded. Eye-movement metrics, subjective workload measure, run time were tested with multivariate analysis of variance (MANOVA), and three way repeated measure analysis of variance (ANOVA). Results At the level of α = 0.05, the experimental factors significantly influence the means of eye movement metrics, subjective ratings and run time. There was also significant influence among their interactions. A positive correlation was also found for eye movements metrics with NASA-TLX and run time. Conclusions Eye movement metrics help in understanding the mental workload of participants unobtrusively and continuously. Analysis of subjective workload measure and run time along with eye-gaze analysis provide a deeper understanding on the pattern of mental workload.

中文翻译：

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评估基于虚拟现实的 EOT 起重机操作中的心理工作量：一种多测量方法

摘要背景眼动指标和主观工作量测量被广泛用于确定参与者的心理工作量。本研究的目的是评估电动桥式 (EOT) 起重机操作员在虚拟 EOT 起重机操作期间基于眼动指标（如注视频率、注视持续时间、跳视持续时间、跳视幅度和注视/跳视比率）的心理工作量变化。基于现实 (VR) 的 EOT 起重机模拟器。方法 设计并进行了一项 2k (k = 3) 因子试验，其中包含危险情景、活动水平和试验等因素，以证明所提出的评估方法。在整个实验过程中，我们记录了作者所在国家钢铁行业的 12 名 EOT 起重机操作员的眼球运动。实验后，采用美国国家航空航天局任务负荷指数（NASA-TLX）作为主观工作量衡量标准，并记录任务完成的运行时间。眼动指标、主观工作量测量、运行时间通过多变量方差分析 (MANOVA) 和三向重复测量方差分析 (ANOVA) 进行测试。结果 在 α = 0.05 的水平上，实验因素显着影响眼动指标、主观评分和运行时间的均值。他们之间的互动也有显着影响。还发现眼动指标与 NASA-TLX 和运行时间呈正相关。结论 眼动指标有助于不显眼且持续地了解参与者的心理工作量。