The role of stress neuromodulators in decision making under risk

偶然的情感状态，即与手头的决策无关的情感状态，可以影响决策。急性压力就是这样一种情感状态，是决策过程中强大的情境调节器。似乎在承受压力后，个体会做出更冒险的决定。就生理和神经激素的变化而言，应激反应已经很好地表征了：暴露于压力会引发一系列自主神经、内分泌和行为反应。生理应激反应是由下丘脑-垂体-肾上腺（HPA）轴和蓝斑去肾上腺能（LC-NA）系统介导的，皮质醇和去甲肾上腺素（NE）是它们的最终产物。有令人信服的证据表明，应激激素皮质醇和NE影响认知过程。然而，到目前为止，只有很少的研究使用药理学方法来明确应激神经调节剂在决策中的作用，而且由于实验设计的差异，这些研究几乎没有可比性，例如，所使用的决策任务。此外，到目前为止，压力对决策影响的神经基础尚未得到研究。因此，研究需要1)系统地区分最重要的应激神经调节剂NE和皮质醇的影响，2)使用区分不同决策过程的任务，如风险态度和损失厌恶，来解开这些神经调节剂及其神经相关物的潜在不同影响。拟议项目的目的是澄清主要的应激神经调节剂NE和皮质醇在与风险下决策相关的不同过程中的作用。为此，我们将结合精确的药理学刺激、行为建模和功能磁共振成像方法，系统地解开应激激素对风险态度和损失厌恶的影响，以及它们与处理主观价值和风险的神经相关物的关系。我们的研究计划包括两项研究。在研究1中，我们将在行为、计算和神经水平上研究去甲肾上腺素能激活和阻断在风险决策中的作用。在研究2中，我们将使用类似的方法来研究皮质醇在有或没有额外的去甲肾上腺素能激活的情况下对风险下决策的影响。

Incidental affective states, i.e., affective states that are unrelated to the decision at hand, can influence decision making. Acute stress is such an affective state and is a powerful contextual modulator of decision-making processes. It appeared that after stress exposure, individuals make riskier decisions.In terms of physiological and neurohormonal changes, the stress response has been well characterized: Exposure to stress elicits an array of autonomic, endocrine, and behavioral responses. The physiological stress response is mediated by the hypothalamic-pituitary adrenal (HPA) axis and the locus coeruleus noradrenergic (LC-NA) system with cortisol and norepinephrine (NE) as their end products. There is compelling evidence that the stress hormones cortisol and NE influence cognitive processes. However, only very few studies so far used pharmacological approaches to specify the role of stress neuromodulators on decision making and these studies are hardly comparable due to differences in the experimental design, e.g., the decision making task used. Furthermore, the neural underpinnings of stress effects on decision making are uninvestigated so far.Thus, studies are needed which 1) systematically differentiate the effects of the most important stress neuromodulators NE and cortisol, and 2) use tasks that differentiate different decision making processes, such as risk attitude and loss aversion to disentangle potentially different effects of these neuromodulators and their neural correlates.The aim of the proposed project is to clarify the role of the major stress neuromodulators, NE and cortisol, in their contribution to different processes related to decision making under risk. To this end, we will combine precise pharmacological stimulation, behavioral modeling, and fMRI methods to systematically disentangle the effects of stress hormones on risk attitudes and loss aversion as well as their relation to neural correlates of processing subjective value and risk. Our research program comprises two studies. In study 1, we will examine the role of noradrenergic activation and blockade on decision making under risk at the behavioral, computational, and neural level. In study 2, we will use a similar approach to investigate the effects of cortisol with and without additional noradrenergic activation on decision making under risk.