Costs and benefits of strategy construction in a speeded discrimination task

The costs and benefits of constructing and utilizing a strategy for performing a speeded discrimination task were assessed in terms of time and mental resources. The strategy involved using information about the position a word occupied in order to respond to its identity more rapidly. The resources used to construct and utilize the strategy were assessed from responses to probes presented at various times during the task. In Experiment 1, the probe required a manual response, whereas in Experiment 2, the probe required a vocal response. Strategy construction interfered with the probe task in Experiment 1 but not in Experiment 2, suggesting that strategy construction required resources specific to the manual response system. There was also some evidence that strategy construction required general resources, but the evidence for specific resources was much stronger. The findings are consistent with our previous ideas about how the strategy is represented (Logan, 1980a; Logan & Zbrodoff, 1979). The different results with different responses to the probes point out important limitations on previous studies of probe interference and of cost-benefit analysis, which each focused on a single dimension of cost and benefit. The differences suggest that a multiple-resources approach to probe interference and cost-benefit analysis might be more appropriate.