Tracking Strategies and Cognitive Demands

The processing demands of two tracking strategies are investigated using an optimum-maximum procedure. Subjects performed two one-dimensional tracking tasks concurrently. Ten subjects employed a double-impulse strategy, and 10 subjects used a continuous strategy. On each task control dynamics were manipulated within subjects, as was the level of optimization. Results showed dual-task decrements but little performance trade-off. These results challenge but do not rule out a resource competition interpretation. Subjects employing the continuous strategy were more adversely affected by increased tracking order than were subjects using the double-impulse strategy. This finding suggests that the continuous strategy demands more central processing resources than does the double-impulse strategy. The implications of these results for workload analysis and dual-task methodology are discussed.