Tufts University, 490 Boston Ave, Medford, MA, 02155, USA.
U.S. Army Combat Capabilities Development Command - Soldier Center, 1 General Greene, Natick, MA, 01760, USA.
Neuropsychologia. 2019 Sep;132:107149. doi: 10.1016/j.neuropsychologia.2019.107149. Epub 2019 Jul 23.
Multitasking behavior is associated with well-known performance costs, but the question of why individuals falter when attempting to manage multiple streams of information remains difficult to answer. One reason for this difficulty may be that multitasking costs are often characterized by isolating component processes that are studied largely independently. In this study, we instead integrate two commonly studied substrates of multitasking, task-switching and dual-tasking, within the same procedural context. This method allows not only a direct comparison of performance costs associated with different demand types but also examination of their interaction. We measured functional brain activation in thirty healthy young adults as they completed a block-design version of the task, observing consistent and separable patterns of frontoparietal activation as a function of demand type. Broadly, task-switching was associated with activation of left premotor and inferior parietal regions, and dual-tasking was associated with activation in regions of right prefrontal and inferior parietal cortex. In the interaction condition, we observed a distributed bilateral pattern of activation across the areas associated with each demand in isolation. These results provide both behavioral and neuroimaging evidence that task-switching and dual-tasking demands can be dissociated and contribute to multitasking costs in unique and separable ways.
多任务行为与众所周知的性能成本有关，但为什么个人在试图管理多个信息流时会出现失误的问题仍然难以回答。造成这种困难的一个原因可能是，多任务成本通常表现为孤立的组件过程，这些过程在很大程度上是独立研究的。在这项研究中，我们在相同的程序环境中整合了两种通常研究的多任务处理子结构，即任务转换和双任务处理。这种方法不仅允许直接比较不同需求类型相关的性能成本，还可以检查它们的相互作用。我们在三十名健康年轻成年人完成任务的块设计版本时测量了他们的大脑功能激活，观察到与需求类型相关的额顶叶激活的一致且可分离的模式。总的来说，任务转换与左前运动和下顶叶区域的激活有关，而双任务处理与右前额叶和下顶叶皮层区域的激活有关。在交互条件下，我们观察到在每个单独需求相关的区域中存在双侧分布式激活模式。这些结果提供了行为和神经影像学证据，表明任务转换和双任务处理需求可以被分离，并以独特和可分离的方式导致多任务处理成本。
