Cortical Circuits for Attention and Decisions

描述（由申请人提供）：我们对皮质功能的理解在很大程度上是静态和模块化的。关于哪些皮层区域表达不同类型的信息，人们已经了解了很多，但是信息如何在皮层中流动，这在很大程度上仍然是推测，间接地从解剖联系中推断出来。考虑两个关键的认知功能：注意和感知决策。我们对这些模块级的功能了解很多，但是这些信号从哪里产生，在哪里流动，以及大脑区域如何相互作用和协作来支持它们，在很大程度上仍然是未知的。为了解决这个问题，我们将训练猴子在一个参数化改变注意力和决策因素的任务中对视觉运动和/或颜色做出判断。我们将同时在前额叶和视觉皮层的大范围区域植入多个电极，记录神经活动。通过比较神经活动的时间动态，我们将测试关于认知信号如何产生和作用于不同皮层区域的本质的基本假设。一种假设是，注意力和决策相关的信号都来自前额叶皮层，然后流向视觉皮层。另一种假设是，自上而下的注意信号产生于前额叶皮层，而感知决策产生于更高层次的视觉皮层。我们还将确定自上而下的信号是否同时作用于皮层层次的不同层次，而不是信号从一个区域级联到另一个区域。我们还将测试信号流模式和皮层区域之间的相互作用是否会随着任务需求而变化。测试这些假设是解决神经精神疾病的关键步骤。越来越多的证据表明，许多疾病可能是由于大脑区域之间的连接和相互作用功能障碍造成的。这项研究将是第一次大规模测试皮层区域之间的相互作用如何支持正常大脑中两种基本和关键的认知功能。

DESCRIPTION (provided by applicant): Our understanding of cortical function is largely static and modular. A lot has been learned about which cortical areas express different types of information, but how information flows through the cortex is still largely conjecture, indirectly inferred from anatomical connections. Consider two critical cognitive functions: attention and perceptual decisions. Much is known about these functions on a modular level, but where these signals arise, where they flow, and how brain areas interact and collaborate to support them is still largely unknown. To address this, we will train monkeys to make judgments about visual motion and/or color in a task designed to parametrically vary attention and decision factors. We will record neural activity from many electrodes simultaneously implanted in a wide range of areas in the frontal and visual cortex. By comparing temporal dynamics of neural activity, we will test fundamental hypotheses about the nature of how cognitive signals arise and act on different cortical areas. One hypothesis is that both attention and decision-related signals arise from prefrontal cortex and flow to visual cortex. The alternative hypothesis is that top-down attention signals arise in the prefrontal cortex, but perception decisions arise in higher-level visual cortex. We will also determine whether top-down signals act simultaneously on different levels of the cortical hierarchy versus the signals cascading from one area to the next. We will also test whether patterns of signal flow and interactions between cortical areas change with task demands. Testing these hypotheses is critical step to addresses neuropsychiatric disorders. There is increasing evidence that many disorders may be due to dysfunction in connections and interactions between brain areas. This study would be the first large scale test of how interactions between cortical areas support two basic and critical cognitive functions in the normal brain. PUBLIC HEALTH RELEVANCE: We will use multiple-electrode technology to record from multiple areas of the cortex while monkeys attend to make decisions about, different stimulus features. Testing these hypotheses is critical step to addressing neuropsychiatric disorders. There is increasing evidence that many disorders may be due to dysfunction in connections and interactions between brain areas. This study would be the first large scale test of how interactions between cortical areas support two basic and critical cognitive functions.