Effect of the balance between operators' processing abilities and required operating speed on operators' task...

The aim of this study is to reveal the effect of the balance between operators' processing abilities and the time constraints imposed upon them in simple repetitive work. In the present study, three experimental conditions for the same tasks which are original pattern recognition ones, but with different ways of setting time limits, were prepared: one time limit was adjusted to each subjects' ability, the second was a uniform and relatively strict time limit, and the third was a uniform and relatively lax time limit. For these three experimental conditions, comparisons were made of task performance indices, subjective indices (NASA-TLX: NASA-Task Load Index, SACL: Stress-Arousal Checklist), and physiological indices (frontal midline theta activity at Fz and the fast a activity at Pz in EEG, and heart rate in ECG). The results showed that individual differences were extremely large in terms of time pressure (TP) effects on task performance and operators' psycho-physiological state if a uniform and strict time limit was imposed on operators with different abilities. Meanwhile, the negative effects of TP on operators were small if they were given a uniform time limit but with enough allowance time. In addition, the results from the frontal midline theta activity in EEG suggest that the patterns in changes of concentration of attention on tasks were different according to the way that the time constraints were set.