Investigating task order control in dual-task situations: The influence of instruction, task complexity, and practice

性能成本（反应时间和/或错误率）发生在人们同时执行两项任务的情况下，而不是孤立的表现。许多理论家用瓶颈机制来解释这些双重任务成本，该机制要求在双重任务情况下串行处理某些过程。许多先前的研究提供了关于瓶颈性质的宝贵知识，即它是由结构性能力限制还是战略选择造成的，以及它是一个全有或全无还是一个共有的瓶颈。然而，尽管有这些知识，但在任务进入瓶颈之前，哪些机制调节和控制任务的顺序，以及主体如何灵活地改变任务在瓶颈处和瓶颈之前的顺序仍然是开放的。该方法预测首先处理首先到达瓶颈的任务，并且不涉及任何进一步的控制机制，当前项目基于替代方法。作为一个主要的假设，我们假设，参与的瓶颈导致竞争的过程之间的访问瓶颈，这种竞争需要招聘额外的控制机制。在瓶颈处的过程的适当顺序需要由额外的过程来计划、控制和调节。这些控制过程是如何工作的？它们的具体机制和原则是什么？本项目的目的是调查这些问题。为此，第一个项目阶段的研究是基于一个任务顺序控制模型，这使我们能够制定不同的预测不同的机制调节任务order.In目前的建议，我们将继续调查任务顺序控制在双任务。新研究的总体目标是阐述一个拟议的任务顺序控制模型，结合瓶颈处理，执行任务顺序控制过程和工作记忆机制的假设。在第一阶段的先前工作表明该模型对于理解双任务中任务顺序控制的重要方面的适用性，但是，另外，提供了新的发现，这需要在第二阶段进一步规范和测试。1）关于双任务中引导任务加工的任务顺序控制表征的内容和结构; 2）关于不同因素对任务顺序控制效率的影响，如顺序指令、工作记忆负荷量、顺序判断标准的类型，以及个人任务顺序偏好。此外，3）我们想研究任务顺序控制可以通过训练优化到什么程度，以及控制的神经实现是什么。

Performance costs (in reaction times and/or error rates) occur in situations in which people perform two tasks simultaneously compared to their isolated performance. Many theorists explain these dual-task costs with a bottleneck mechanism that requires serial processing of certain processes in dual-task situations. Many previous studies have provided valuable knowledge about the nature of the bottleneck, i.e. whether it is caused by structural capacity limitation or a strategic choice and whether it is an all-or-none or a shared bottleneck. However, despite this knowledge, it is still open which mechanisms regulate and control the order of the tasks before they enter the bottleneck and how subjects can flexibly change the order of the tasks at and before the bottleneck.While the traditional bottleneck model assumed a passive mechanism for determining task order, which predicts that that task is processed first which arrives first the bottleneck and which does not involve any further control mechanisms, the current project is based on an alternative approach. As a main presumption, we assume that the involvement of a bottleneck leads to competition between processes for access to the bottleneck and this competition requires the recruitment of additional control mechanisms. The appropriate order of the processes at the bottleneck needs to be planned, controlled, and regulated by additional processes. How do these control processes work? What are their specific mechanisms and principles? The aim of the current project is to investigate these questions. For that purpose the research on the first project phase was based on a task order control model, which allowed us formulating different predictions about different mechanisms regulating task order.In the current proposal we will continue to investigate task order control in dual tasks. The overarching goal of the new studies is the elaboration of a proposed task order control model that combines assumptions about bottleneck processing, executive task order control processes, and working memory mechanisms. Prior work in the first phase showed suitability of the model for understanding important aspects of task order control in dual tasks, but, additionally, provided new findings, which require further specification and testing in the second phase.For that purpose we aim to conduct several series of experiments, which are aimed at testing the predictions of the task order control model, 1) concerning the content and the structure of task order control representations guiding task processing in dual tasks, and 2) concerning the influence of different factors on the efficiency of task order control, such as the order instruction, the amount of working memory load, the type of the order decision criterion, and of individual task order preferences. Further, 3) we want to investigate to which degree task order control can be optimized by training and what the neural implementation of the control is.