Head-slaved Tracking in a See-through Hmd: the Effects of a Secondary Visual Monitoring Task on Performance and Workload

Technological advances in helmet-mounted displays (HMDs) have permitted the design of “see-through” displays in which virtual imagery may be superimposed upon real visual environments. The utility of see-through displays in multitask environments remains uncertain, especially in environments that involve switching one’s attention between those tasks represented in the virtual display and those existing in the real world. The present study was designed to assess the effects of a secondary visual monitoring task on performance and workload in a head-slaved tracking task. Participants attempted to center a reticle over a moving circular target using a Kaiser Electronics SimEye 2500 HMD while concurrently performing the visual monitoring task component of the Multi-Attribute Task Battery (MATB; Comstock & Arnegard, 1992), which was displayed on a computer monitor. Task difficulty for the head-slaved tracking task was varied by manipulating time delay. Results are discussed in terms of their implications for practical implementation of see-through HMDs in multi-task environments.