Comparison of Operating Method of Extra Limbs in Dual Tasks: Point and Path Instruction

This paper discusses methods to manipulate an extra limb at the same time as the user's body parts. Two types of extra limb manipulation methods exist: path instruction, which involves continuous input such the master-slave method, and point instruction, which only involves commands of the coordinates of the required transit points. Intuitively, point instruction is considered to be easier to use for simultaneous operations because the attention time per instruction is shorter. In contrast, from a cognitive science perspective, depending on the amount of attention switching involved during the tasks and the attention level required for each task, it may be easier to perform dual tasks with path instruction than with point instruction. Therefore, we conducted a user study to compare the feasibility of using point instruction and path instruction in tasks that require considerable attention switching and tasks that do not as well as tasks that require a high level of attention for execution and tasks that do not. The results showed that point instruction improved work efficiency in all task conditions, but path instruction improved work efficiency only when the task was easy to perform. These results suggest the superiority of point instruction and also indicates that the need for intermittent attention allocation, such as the time and frequency of each session, should be further discussed.