Dual-task costs might result from confusions on the task-set level as both tasks are not represented as distinct task-sets, but rather being integrated into a single task-set. This suggests that events in the two tasks are stored and retrieved together as an integrated memory episode. In a series of three experiments, we tested for such integrated task processing and whether it can be modulated by regularities between the stimuli of the two tasks (across-task contingencies) or by sequential regularities within one of the tasks (within-task contingencies). Building on the experimental approach of feature binding in action control, we tested whether the participants in a dual-tasking experiment will show partial-repetition costs: they should be slower when only the stimulus in one of the two tasks is repeated from Trial n − 1 to Trial n than when the stimuli in both tasks repeat. In all three experiments, the participants processed a visual-manual and an auditory-vocal tone-discrimination task which were always presented concurrently. In Experiment 1, we show that retrieval of Trial n − 1 episodes is stable across practice if the stimulus material is drawn randomly. Across-task contingencies (Experiment 2) and sequential regularities within a task (Experiment 3) can compete with n − 1-based retrieval leading to a reduction of partial-repetition costs with practice. Overall the results suggest that participants do not separate the processing of the two tasks, yet, within-task contingencies might reduce integrated task processing.

双重任务成本可能是由于任务集级别的混淆造成的，因为这两个任务没有表示为不同的任务集，而是被集成到单个任务集中。这表明两个任务中的事件作为一个集成的记忆片段一起存储和检索。在一系列三个实验中，我们测试了这种集成任务处理，以及它是否可以通过两个任务的刺激之间的规律性（跨任务意外事件）或通过其中一个任务内的顺序规律性（任务内意外事件）来调节. 在动作控制中特征绑定的实验方法的基础上，我们测试了双任务实验的参与者是否会表现出部分重复成本：当仅从试验n中重复两个任务之一中的刺激时，他们应该更慢− 1 到试验n比两个任务中的刺激重复时。在所有三个实验中，参与者处理了视觉-手动和听觉-声调辨别任务，它们总是同时呈现。在实验 1 中，我们表明，如果随机抽取刺激材料，则试验n -1 集的检索在实践中是稳定的。跨任务的意外事件（实验 2）和任务中的顺序规律（实验 3）可以与基于n -1 的检索竞争，从而通过实践降低部分重复成本。总体而言，结果表明参与者不会将这两个任务的处理分开，但是，任务内的突发事件可能会减少集成的任务处理。