Effects of Cueinq and Knowledge of Results on Workload and Boredom in Sustained Attention

摘要

Two models of recently reported high workload associated with vigilance tasks are the direct-cost and indirect-cost views. The former attributes high workload to the need for continuous observation in discriminating signals from neutral events; the latter attributes it to efforts to combat the boredom associated with monotonous Vigilance tasks. These opposing views were tested by providing observers with reli- able cueing, which rendered observation necessary only when low-probability crit- ical signals were imminent, or with knowledge of results (KR) regarding performance efficiency On the basis of cue and KR differences in elicited observa- tion activity and motivational value, the direct-cost model led to the anticipation that cueing would result in a high-boredom, low-workload profile and a greater reduction in workload than KR. The indirect-cost model led to the prediction that cueing would result in a high-boredom, high-workload profile and a lesser reduc- tion in workload than KR. The results clearly supported the direct-cost view that the workload of vigilance is task-induced. Consequently, efforts to combat high workload in complex automated systems requiring substantial monitoring by oper- ators should focus specifically upon task-related determinants.