Multi-dimensional Assessment Of The Mental Workload Of Cognitive Control Operations And Its Influencing Factors

With the development of computer technology, more and more cognitive monitoring tasks have appeared in many fields. The mental workload in such tasks has attracted more and more attention. This paper evaluated the workload in such tasks by using primary task measure, subsidiary task measure and subjective mental workload evaluation. The effects of event frequency and signal probability on the performance and subjective mental workload in such tasks were also investigated. The whole study was composed of two experiments:The experiment 1: the multi-dimension evaluation of the mental workload in cognitive monitoring tasks.The experiment 2: the effects of event frequency and signal probability on the performance and subjective mental workload in cognitive monitoring tasks.The results suggested that:(1) The primary task measure, subsidiary task measure and subjective mental workload evaluation all had significant sensibility to the changes of workload level in cognitive monitoring tasks. There were significant relations among these measurements, which implied that these techniques of measurement all had good reliability.(2) In evaluating the mental workload of cognitive monitoring tasks, the indexes of hit rate and accurate reaction time in primary task measure, accurate reaction time rate and its two covariate corrected values in subsidiary task measure, weighted workload score (WWL) in subjective mental workload evaluation all had significant sensibility to the changes of workload level in this experiment.(3) In the cognitive monitoring tasks, both the event frequency and signal probability had significant effects on the performance. The performance under high event frequency and high signal probability conditions was better than low event frequency and low signal probability. The event frequency had significant effects on the subjective workload. The workload level under high event frequency conditions was higher than low event frequency. The signal probability didn't affect the subjective workload so much as the event frequency did. It was found that there was some "dissociation" between the objective performance measurement and the results of subjective evaluation.