NRSA: Dynamic evaluation and control of decision making

描述（由申请人提供）：我们拟研究人类的基本决策机制，包括感觉统合、假设检验和反应选择。我们还建议研究调节这些决策过程以响应不同任务条件所必需的控制机制。我们建议使用事件相关脑电图（EEC）和功能磁共振成像（fMRI）来研究这些机制，以补充我们现有的行为研究结果。我们提出要解决的主要问题是，非人类灵长类动物知觉决策背后的神经回路的简单“泄漏竞争累加器”（LCA）模型是否在人类大脑中实现；如果是这样，是否有证据证明我们开发的这个模型的扩展，可以解释与认知控制相关的行为适应-这是大多数精神疾病的核心障碍。非人类灵长类动物的直接神经元记录支持了一个简单的LCA感觉统合模型和假设检验，该模型表明，在需要眼动反应的运动辨别任务中，外侧顶叶内沟（LIP）区域的神经元执行证据权衡过程。此外，这种活动受到与可能结果相关的预期奖励的调节。我们的假设是，这些现象反映了在大多数任务中支配所有反应模式的三个普遍的、跨物种的原则：1)刺激-反应关联在处理的中间阶段在大脑中实现，将刺激识别阶段的输出转化为反应启动；2)在这些反应通道的初始阶段，加速活动不仅反映了在反应之前对预期运动特征的预先准备，而且——关键的是——它还反映了对采取哪种反应的证据的实际权衡；3)认知控制的最简单形式是在这一阶段通过在持续奖励和成本监测的基础上调节应用于该证据的阈值来实现的。我们建议使用包含两种反应模式和奖励偶然性的多重操作的动作辨别任务来检验这一假设。这项任务非常适合将我们的非侵入性结果与直接记录数据结合起来，我们开发的涉及这项任务的电路模型允许对所有模型组件的激活时间剖面进行强有力的定量预测。这项任务可能提供了一个窗口，了解由伤害或精神疾病引起的情感障碍通过不适当的阈值控制导致基本认知加工障碍的过程。这也可以解释控制缺陷是如何导致奖励处理受损的。

DESCRIPTION (provided by applicant): We propose to study basic human decision making mechanisms of sensory integration, hypothesis testing and response selection. We also propose to study the control mechanisms necessary for modulating these decision making processes in response to varying task conditions. We propose to investigate these mechanisms using event-related encephalography (EEC) and functional magnetic resonance imaging (fMRI) to complement our existing behavioral results. The major questions that we propose to address are whether a simple "leaky competing accumulator" (LCA) model of the neural circuitry underlying perceptual decision making in non-human primates is implemented in the human brain; and if so, whether evidence exists for an extension which we have developed of this model that can account for adaptations of performance associated with cognitive control -a disturbance of which is central to most forms of psychiatric disorder. A simple LCA model of sensory integration and hypothesis testing that is supported by direct neuronal recordings in non-human primates suggests that neurons in the lateral intraparietal sulcus (area LIP) implement an evidence-weighing process in the context of motion-discrimination tasks requiring eye-movement responses. Furthermore, this activity is modulated by the expected reward associated with possible outcomes. Our hypothesis is that these phenomena reflect three general, cross-species principles that govern all response modalities in most tasks: 1) stimulus-response associations are implemented in the brain at intermediate stages of processing that transform the outputs of stimulus identification stages into response initiation; 2) ramping activity in these initial stages of the response channels reflects not only the advance preparation of anticipated movement features prior to a response, but also - critically - it reflects the actual weighing of evidence about which response to make; 3) cognitive control in its simplest form is implemented at this stage by modulating the threshold applied to this evidence on the basis of continuous reward and cost monitoring. We propose to test this hypothesis using a motion-discrimination task involving two response modalities and multiple manipulations of reward contingency. This task is well suited for aligning our noninvasive results with direct recording data, and the model we have developed of circuits involved in this task allow strong, quantitative predictions about the temporal profile of activation in all of the model's components. This task may provide a window into the process by which disturbances of affect resulting from injury or psychiatric disease lead to disturbances of basic cognitive processing through inappropriate threshold control. It may also explain how control deficits lead to impaired reward processing.