Dual-Task Interference while Receiving Information on a Head Mounted Display, Visually on the Same Depth Plane, or Audibly

Wearable displays may enhance information access, but potential interference between device use and the primary operational task may result. Multiple Resource Theory (2002) helps predict which information modalities will interfere, but in the case of head mounted displays (HMDs), the importance of competition for focal attention versus central processing resources in determining dual-task interference remains unclear. We investigated the interference between manual tracking and a word memory task, where words were presented on a HMD, the same display as the tracking task, or audibly. Compared to single-task tracking, performance was impaired by both audio and HMD word presentation, but not by words presented on the same visual plane. This suggests some interference is due to demands on vison itself, not just central resources, and that bottom-up shifts in information seeking may also impair performance. Future research into the best methods of utilizing wearable aids and directing user attention is needed.