Voice and Manual Control in Dual Task Situations

This paper describes various influences of compatibility and task-resource competition that affect time-sharing a verbal and a manual control task, with either manual or voice control. In the reported experiment subjects performed a 2-dimensional discrete tracking task concurrently with a Sternberg memory search task. Each task was controlled either by voice, the left hand, or the right hand. The major influence on performance was the advantage for conditions in which the Sternberg task was voice-controlled and tracking was manually controlled. Voice-controlled tracking produced incompatibility, while bimanual control produced resource competition. Smaller, but still reliable effects were observed for hemispherically-compatible assignments (left-handed tracking).