Technical report: cognitive demands of the Integrated Digital Helmet System (IDHS)

Information delivery systems aid operator performance and improve situation awareness, but processing the information they present requires cognitive resources. Excessive or intrusive information can overload these cognitive resources, and performance can suffer. In high-stress scenarios, such as combat, information-systems overload can have counterproductive effects. This study assessed the cognitive impact of the Integrated Digital Helmet System’s (IDHS) visualisations on operators. We devised two computer based experiments to assess the impact of IDHS visualisations on operators’ performance and cognitive workload. Exp 1, the Shooting Range Safety task, utilised control measure visualisations and alerts. Exp 2, the Friend or Foe task, utilised a visualisation providing situation awareness and orientation. We used the detection response task (DRT), a simple cognitive task designed for applied settings, to assess cognitive workload while participants completed these experiments. Visualisations improved performance on the Shooting Range Safety task with limited cognitive impact, while the presence of visualisations imposed a significant workload cost in the Friend or Foe task, with little benefit to performance. These findings indicate that useful information can nonetheless be intrusive, and that only critical information that is not otherwise available to the operator should be conveyed during periods of high cognitive workload. The methodology used in this report has been shown to be sensitive to the workload effects of visualisations. Information delivery systems developed in the future can be assessed using this methodology, with the potential to identify the optimal system configuration for different scenarios. With the use of portable hardware, prototype helmets could be assessed in simulation or field tests, using subject matter experts or Defence personnel to evaluate candidate visualisations alongside the objective measures used here.