The role of task-specific information for task-order coordination and coordination adjustment in dual-task situations

Performing two tasks simultaneously requires the coordination of their processing, particularly in dual-task contexts in which the order of the component tasks varies. When the task-order alternates across consecutive trials, coordination demands lead to performance impairments on current trials under different-order versus same-order conditions relative to the previous trials (i.e., order-switch costs). These performance decrements are assumed to rely on task-order information that is actively maintained and processed within task-order representations. Kübler et al. (2022) demonstrated that task-order representations exclusively contain task-order information, but no information about the individual tasks themselves (e.g., specific stimuli or stimulus-response mappings).This was demonstrated by findings showing that order-switch costs occurred irrespective of whether the specific task was repeated or changed. Moreover, previous research has shown that task-order coordination adapts to prior experience with task-order switches versus task-order repetitions, resulting in a Gratton-like effect (i.e., switch adjustment effect; Gratton et al., 1992; Strobach, 2024; Strobach et al., 2021). Order-switch costs in current trials (Trials N) were reduced when the preceding trials (Trials N-1) involved different-order relative to same-order conditions. However, it remains an open question whether such adjustments in task-order coordination are also independent of representations of the specific tasks. Therefore, the present study investigates task-order coordination and coordination adjustment when the specific task varies within an auditory-visual dual-task paradigm.