ABSTRACT
Many jobs involve performing two or more tasks concurrently. For example, air traffic controllers must coordinate the movements of many airplanes as they move through the controllers’ designated sectors so that the planes are at safe separations from one another and are following the correct flight paths. At the same time, the controllers have to ensure that the pilots are receiving proper instructions about detours to avoid bad weather and turbulence and that the pilots are able to take off and land in an orderly fashion (Freudenrich, 2005). Multiple tasks not only increase the information-processing demands placed on the operator, but they also provide an opportunity for various interactions between tasks to occur. Moreover, performance of multiple tasks requires coordination of processes for the tasks that is not necessary when each task is performed in isolation. Because response selection and other central-processing requirements are more complex in situations that require multiple-task performance, issues of S-R compatibility become more multifaceted. Maintaining compatibility of the stimuli and responses within each task remains important, but, in addition, the relation between the stimuli and responses across the tasks is critical and can affect performance in several ways.
