Electrophysiological and Computational studies on action monitoring

人类如何规范自己的行为是一个基本问题。在国家科学基金会的资助下，布朗大学的迈克尔·弗兰克博士正在研究不同大脑区域之间的相互作用，这些区域涉及人们如何监控、学习和控制自己的行为。这项研究的重点是人类如何在面对困难的决定时实现对行为的克制控制。理论模型和经验结果表明，在这些动机行为中，前额叶皮质和基底节相互作用，神经化学物质多巴胺在前额叶和基底节脑区都起着中心作用。研究人员使用脑电图(EEG)测量参与者与前额叶皮质活动相关的脑电波，同时他们执行计算机化的认知任务，在困难的环境中评估学习和决策。脑波活动预计将预测参与者在这些任务中的认知表现。关键的是，这种大脑-行为关系被预测为前额叶皮质和基底节中多巴胺功能的遗传变异的函数。在另一项实验中，研究人员直接在药物上操纵多巴胺，以确定这些大脑和行为关系是如何因多巴胺水平而发生变化的。在他们的所有研究中，研究人员使用当代理论指导下的详细数学模型来分离特定的大脑-行为关系。从理论上讲，遗传变异和药物操纵都会影响大脑监测、学习和控制行动的方式。脑电波测量使研究团队能够定义神经化学物质如何调节大型神经系统的过程。这项研究的目标是大幅提高我们对人类如何能够根据动机和认知控制来调节行为的理解。科学家们普遍认识到，这些类型的动机行为存在很大的个体差异，但直到最近，他们才开始了解控制这些差异的一些因素。通过结合多种研究方法，该项目旨在揭示遗传和神经化学因素如何改变与此类行为密切相关的大脑区域的活动。该项目还有可能确定扰乱大脑电路并导致动机行为和认知控制障碍的机制，包括成瘾和强迫症等。

How humans regulate their behaviors is a fundamental question. With funding from the National Science Foundation, Dr. Michael Frank of Brown University is investigating interactions between different brain regions involved in how people monitor, learn, and control their actions. This research project focuses on how humans accomplish restrained control over behavior when confronted with difficult decisions. Theoretical models and empirical results suggest that the prefrontal cortex and the basal ganglia interact during these motivated behaviors, and that the neurochemical dopamine plays a central role in both the prefrontal cortex and basal ganglia brain regions. Using electroencephalography (EEG), the investigators are measuring participants' brain waves associated with prefrontal cortex activity, while they perform computerized cognitive tasks that assess learning and decision making in difficult circumstances. The brain wave activity is expected to predict participants' cognitive performance on these tasks. Critically, this brain-behavior relationship is predicted to differ as a function of genetic variants in dopamine function in both the prefrontal cortex and basal ganglia. In another experiment, researchers are directly manipulating dopamine pharmacologically in order to determine how these brain and behavior relationships are causally altered by dopamine levels. In all of their studies, the investigators use detailed mathematical models guided by contemporary theory to isolate specific brain-behavior relationships. It is theorized that both genetic variants and pharmacological manipulations affect the way that the brain monitors, learns, and controls actions. The brain wave measures are allowing the research team to define how neurochemicals modulate the processes of large neural systems.This research has the goal to substantially advance our understanding of how humans are able to regulate their behaviors as a function of motivation and cognitive control. Scientists widely appreciate that there are large individual differences in these types of motivated behaviors, but only recently have they begun to understand some of the factors governing these differences. By combining multiple research approaches, this project is posed to reveal the ways in which genetic and neurochemical factors alter activity in brain areas that are critically involved in such behaviors. The project also has the potential to identify mechanisms that disrupt brain circuitry and lead to disorders in motivated behavior and cognitive control, including addiction and obsessive compulsive disorder among others.