Use of Disjunctive Response Requirements in Dual-Task Environments: Implications for Automation

Two experiments were conducted to assess the difference in resource requirements for choice and disjunctive (Donders Type c) responding in a dual-task environment. Experiment 1 utilized two binary tasks paired in all possible combinations of choice and disjunctive response requirements. For both tasks the disjunctive responses were faster and less error prone with the additional benefit of improving performance on the concurrent task. Experiment 2, using a primary-secondary dual-task paradigm, contrasted the resource cost of responding to the cost of not responding to stimuli that had varying degrees of similarity to the 'go' stimuli. Results demonstrated a high degree of operator involvement in terms of resource use even when a response was not required. These results were discussed in terms of reducing operator workload within a semiautomated multitask environment by employing disjunctive responding in place of binary choice responding. (Author)