Assessment of Mental Workload Levels Using the Subjective, Objective, and Performance-Based Measures: A Sensitivity Analysis

Background:One of the key elements in situations with higher levels of relief, performance, and safety is mental workload (MWL). Thus, using a sensitive measure to accurate detection of different levels of MWL difficulties is essential. Therefore, we aimed to assess and compare different level of MWL difficulties in males and females by applying some objective, subjective, and performance measures among Iranian community.Materials & Methods:Twenty-six healthy males and females students participated to complete a computerized dual task, with two levels of difficulty, each with a duration of 5 minutes. An objective measure, heart rate variability (HRV), and two subjective measures including The National Aeronautics and Space Administration Task Load Index (NASA-TLX) and Rating Scale Mental Effort (RSME) were used to assess the MWL. In addition, objective data was gathered during a 5-minute resting period. Independent and Paired sample T-test, and repeated measure ANOVA followed by Bonferroni post hoc test were applied. The effect size was estimated using the Cohen’dz statistic for all variables.Results:The results indicated that the most sensitive measures are performance responses (effect size [dz] male; female= 1.71; 1.12), following by weighted NASA-TLX score and the non-linear HRV variable of alpha2 for males (dz=0.69) and unweighted NASA-TLX score for females (dz=0.68). The only and most sensitive measure to distinguish between genders was weighted NASA-TLX score (p .).0.0