Does Dual-Axis Tracking Demand More Resources Than Single-Axis Tracking

摘要

Earlier studies (Gopher & Navon, in press) indicated that when control dynamics is simple, vertical and horizontal tracking interfere very little with each other. The present study was designed to test in a systematic way the possible effects of three elements in a dual-axis tracking situation: the addition of an axis in itself, the presence of visual feedback-indicators, and the requirements to allocate resources unevenly between the axes. Practiced subjects were required to make binary classification of visually presented digits while tracking; digits were presented within a moving square that served as the target for tracking. Small dual-task deficits were found in the performance of both tracking and digit classification. Their small extent suggests that we succeeded to eliminate a major source of structural conflict. The condition of tracking did not have a discernible effect on either task. Hence, the introduction of a second tracking axis probably does not have harmful consequences either on tracking itself or on any other task time-shared with tracking. The results are interpreted within the framework of a multiple resource approach (Navon & Gopher, 1979). (Author)