HOW INHIBITORY CONTROL MODIFIES STIMULUS VALUE AND MOTIVATION

描述（由申请人提供）：日常自控行为，如吸烟、饮食和赌博，部分取决于停止行为的能力。虽然我们对人类的行为停止有很多了解，但现实世界的自我控制，就像上面的例子一样，有很强的价值或动机成分。然而，关于马达停止如何与价值/动机相互作用的研究却很少。基于初步数据，我们的核心假设是，电机停止会降低价值和动机。我们将根据我们的工作，用三种停止系统测试三种可能的机制。我们的第一个目标是测试同时快速停止如何降低刺激值。我们假设快速停止招募一个全球停止系统，抑制所有当前活跃的表征，包括价值。测试这一点需要测量整体抑制（使用经颅磁刺激，TMS），对停止系统和价值表征成像（使用功能磁共振成像和皮质电成像），最重要的是，显示对停止至关重要的大脑区域对降低价值有因果关系

DESCRIPTION (provided by applicant): Everyday acts of self-control directed at, for example, cigarettes, food, and gambling, depend, in part, on the ability to stop action. While much is known about action stopping in humans, real world self-control, as in the above examples, has a strong valuational or motivational component. Yet there is scant research on how motor stopping interacts with value/motivation. Our core hypothesis, based on preliminary data, is that motor stopping can reduce value and motivation. We will test three possible mechanisms based on our work with three kinds of stopping systems. Our first aim is to test how rapid stopping concurrently reduces stimulus value. We hypothesize that rapid stopping recruits a global stopping system that inhibits all currently active representations, including value. Testing this requires measuring global inhibition (with Transcranial Magnetic Stimulation, TMS), imaging the stopping system and value representations (with fMRI and Electrocorticography) and, above all, showing that brain regions critical for stopping are causally important for reducing value (using a novel form of Direct Electrical Stimulation, in humans). Our second aim is to examine how motivational stimuli, which generate action tendencies, are suppressed. Our hypothesis is that this is done by the selective stopping system that is set up according to a subject's goals in working memory and which can be triggered by the motivational stimulus itself. We will test this by measuring the temporal dynamics of motor activation and suppression with TMS, and using fMRI to examine the putative underlying fronto-striatal system. Our third aim is to leverage automatic stopping to reduce stimulus value and motivation. We hypothesize that repeated stopping (via training) generates stimulus stop-tag, so that when that stimulus occurs in the future it reactivates the stopping system (automatically), which then reduces stimulus value and motivation.