Decision making in a dynamic situation: The effect of false alarms and time pressure

An experiment was conducted to investigate the effect of a priori probability of false alarms and time pressure on decision‐making behaviour in a dynamic task environment. In order to assess whether strategy selection in a dynamic task environment would be adaptive, we modelled the task mathematically, and compared actual decision strategies to the optimal ones. In addition to the selected strategy, we also studied decision‐making behaviour at a lower operational level, reflecting the amount of effort subjects are willing to spend on the decision process. Subjects were required to monitor the fitness level of a simulated athlete, who was running a race, and had to provide treatments whenever the athlete's fitness level suggested a real physiological problem. When a decline of the athlete's fitness was caused by a false alarm, a spontaneous recovery would occur after some time, without any need for intervention. Time pressure was manipulated by the rate at which the athlete's fitness level declined. Overall, subjects did not select the most efficient strategy: they dominantly selected information before applying an action, even though it would have been more profitable, and less effortful, just to apply actions. At the operational level, subjects appeared to invest less effort when the probability of false alarms increased and to invest more effort when time pressure increased. However, in contrast to the outcomes of our mathematical model, subjects adjusted the amount of intervention to the a priori probability of false alarms and not to time pressure. Together, the results indicate that the selection of a decision strategy in a dynamic task is less adaptive then is generally concluded from studies with static tasks.