The neural bases of task proficiency and dual-tasking: Escaping the frontal bottleneck

人类认知最令人印象深刻的方面之一是，它能够通过练习将费力的任务转化为几乎不费力气就能完成的任务，甚至与其他需要注意的任务并行执行。最近，在我们的文化中，允许持续参与的技术的激增使一心多用变得越来越普遍，这引发了新的政策挑战，因为人们在一心多用的尝试超过了他们的认知能力，比如开车时发短信。因此，更好地了解大脑自动执行任务的能力和局限性是非常必要的。然而，自主性和多任务处理的神经基础仍然知之甚少，导致人们对大脑的多任务处理能力存在很大分歧。特别是，尽管有广泛的共识认为，学习新任务与大脑前部任务选择回路的发展有关，但一些实验表明，当需要同时执行多项任务时，这种结构可能会造成认知“瓶颈”。乔治城大学的马克西米利安·里森乌伯博士和他的团队正在测试一项关键假设，即在特定条件下，熟悉的任务可以被“卸载”到大脑后部的回路，从而解放额叶系统，同时执行额外的、需要注意力的任务。为了验证这一假设，该项目将使用复杂的行为训练范式，使参与者能够并行执行多项任务，然后使用先进的功能磁共振成像(FMRI)和脑电(EEG)技术的组合来跟踪大脑如何学习以实现多任务处理。这项研究将促进我们对大脑自动化和并行化任务执行能力背后的机制的理解，在当今文化中，面对越来越大的多任务压力，这一能力至关重要。这一结果也将与一系列社会和医学挑战相关。例如，多任务和任务切换方面的缺陷与精神分裂症和注意力缺陷多动障碍有关。此外，人们越来越认识到，自动化本身可能会带来负面后果，因为自动化过程会因缺乏意识和控制减少而降低应对的灵活性。例如，治疗药物成瘾的一个挑战是，许多与药物滥用有关的适应不良行为变得自动化。即使与高性能相关，在问责至关重要的领域，例如在法律或医疗决策中，自动任务执行也可能是有问题的。了解大脑如何将任务自动化是在这些领域取得进展的关键踏脚石。

One of the most impressive aspects of human cognition is its ability to, through practice, convert effortful tasks to those that can be performed with little effort, and even in parallel with other, attention-demanding tasks. The recent proliferation of technologies permitting constant engagement in our culture has made multitasking increasingly prevalent, giving rise to new policy challenges as people's attempts at multitasking exceed their cognitive capabilities, such as when texting while driving. A better understanding of the brain's capabilities and limitations to automate tasks is therefore highly desirable. Yet, the neural bases of automaticity and multitasking are still poorly understood, leading to substantial disagreement about the brain's multitasking capabilities. In particular, while there is broad consensus that learning new tasks is associated with the development of task-selective circuits in the front of the brain which are selectively activated or suppressed depending on the individual's attentional focus, several experiments have shown that this architecture can create a cognitive "bottleneck" in situations when more than one task needs to be executed at the same time. Dr. Maximilian Riesenhuber and his team at Georgetown University are testing the key hypothesis that under certain conditions, familiar tasks can be "offloaded" to circuits in the back of the brain, thus freeing up the frontal system to simultaneously perform additional, attention-demanding tasks. To test this hypothesis, the project will use sophisticated behavioral training paradigms to enable participants to perform more than one task in parallel, and then use a combination of advanced functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) techniques to track how the brain learns to enable multitasking. The study will advance our understanding of the mechanisms underlying the brain's ability to automatize and parallelize task execution, essential in the face of the increasing pressures to multitask in today's culture. The results will also be relevant for a range of societal and medical challenges. For instance, deficits in multitasking and task switching have been associated with schizophrenia and attention deficit hyperactivity disorder. In addition, it is being increasingly appreciated that automaticity itself can be associated with negative consequences, as automatic processes can reduce flexibility in responding due to a lack of conscious awareness and decreased control. For instance, a challenge in treating drug addiction is that many maladaptive behaviors associated with drug abuse become automatized. Even when associated with high performance, automatic task execution can be problematic in domains in which accountability is critical, such as in legal or medical decision-making. Understanding how the brain automatizes tasks is a key stepping stone in making progress in these areas.