Decision-making under stress: which brain system guides choice?

决策可以由不同的机制来支持，这些机制在神经基质和处理的信息方面都不同。这也是学分分配的情况，它描述了适当分配结果的问题，奖励或惩罚，正确的选择。这个问题可以通过使用结果与其正确的因果选择之间的偶然关联来解决，这依赖于眶额皮质，或者通过分别由杏仁核和背外侧纹状体支持的（非偶然）统计和启发式机制来解决。虽然这些不同机制的招募可能会导致根本不同的决定，但决定这些机制在多大程度上控制行为的因素却知之甚少。压力是认知的主要调节器。具体来说，压力被认为会改变参与记忆过程的独立系统的参与。基于这些数据，我们假设，压力也可以调节招聘的解剖和功能不同的机制，在决策。为了验证这一假设，我们将健康的参与者暴露在一个标准化的压力源或控制操纵之前，他们执行的信用分配任务，已被证明揭示了或然和非或然的学习机制。为了研究压力对这些不同机制的影响的神经基础，志愿者将在任务执行期间进行3T的fMRI扫描。我们预测，压力会增加非权变机制对行为的贡献，代价是精确的权变学习。在神经层面，我们预计压力会增加杏仁核，但减少外侧眶额皮质参与决策。除了与我们对压力如何塑造决策的一般理解相关外，该项目的发现可能对与压力相关的精神病理学以及与工作相关的环境具有重要意义，其中与压力相关的精神病理学中决策缺陷是突出的，而与工作相关的环境中决策通常是在压力下做出的。

Decision-making can be supported by separate mechanisms that differ in their neural substrate and in the information processed. This is also the case for credit assignment, which describes the problem of appropriately assigning outcomes, rewarding or punishing, to the correct choices. This problem can be solved using contingent associations between outcomes and their correct causal choices, which is reliant on orbitofrontal cortex, or by (non-contingent) statistical and heuristic mechanisms supported by amygdala and dorsolateral striatum, respectively. Although the recruitment of these distinct mechanisms may result in fundamentally different decisions, the factors that determine to what extent these mechanisms exert control over behavior is poorly understood. Stress is a major modulator of cognition. Specifically, stress is thought to alter the engagement of separate systems involved in memory processes. Based on these data, we hypothesize that stress may also modulate the recruitment of anatomically and functionally distinct mechanisms in decision-making. To test this hypothesis, we will expose healthy participants to a standardized stressor or a control manipulation before they perform a credit assignment task that has been shown to reveal both contingent and non-contingent learning mechanisms. In order to examine the neural basis of the influence of stress on these distinct mechanisms, volunteers will be scanned with fMRI at 3T during task performance. We predict that stress will increase the contribution of non-contingent mechanisms to behavior, at the expense of precise contingent learning. At the neural level, we expect that stress will increase amygdala but decrease lateral orbitofrontal cortex involvement in decision-making. Beyond their relevance for our general understanding of how stress shapes decision-making, the findings of this project may have important implications for stress-related psychopathologies, in which decision-making deficits are prominent, as well as for work-related settings, in which decisions are often made under stress.