Neural mechanisms of decision-making under uncertainty in PTSD

PTSD不确定性下决策的神经机制

• 批准号: 8709712
• 负责人: ILAN HARPAZ-ROTEM
• 金额: $ 24.98万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-17 至 2016-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8709712
• 关键词: Accidents; Affect; Amygdaloid structure; Area; Attitude; Behavior; Behavioral; Behavioral Mechanisms; Biological Markers; Cessation of life; Choice Behavior; Cognitive Therapy; Corpus striatum structure; Decision Making; Development; Disease; Distress; Economics; Emotional; Event; Fright; Functional Magnetic Resonance Imaging; General Population; Individual; Lead; Maintenance; Medial; Methodology; Methods; Neurobiology; Outcome; Patient Self-Report; Patients; Pattern; Pharmacotherapy; Population; Post-Traumatic Stress Disorders; Predisposition; Prefrontal Cortex; Probability; Process; Quality of life; Reaction; Risk; Severities; Shapes; Soldier; Survivors; Symptoms; Testing; Therapeutic; Time; Trauma; Uncertainty; Weight; adverse outcome; base; coping; experience; improved; loved ones; neuroeconomics; neuromechanism; novel strategies; prevent; protective effect; public health relevance; relating to nervous system; therapy design; tool

DESCRIPTION (provided by applicant): Posttraumatic stress disorder (PTSD) affects a significant proportion of the population, with general population estimates ranging from 6.4% to 6.8%. To-date there is no biological markers to identify individuals at risk for PTSD, and available treatments are only partially successful. Understanding the behavioral and neural mechanisms that underlie the development and maintenance of PTSD is important in order to inform and refine behavioral and pharmacotherapeutic interventions designed to improve patients' quality of life and, ideally, to prevent the disorder in the first place. One aspect of mst traumas that is widely ignored in the context of PTSD is the high levels of uncertainty surrounding highly adverse circumstances. In the battlefield, for example, soldiers are aware of the various dangers to themselves and others, but are seldom able to estimate the likelihood for the realization of those dangers. An adverse outcome combined with the distress of uncertainty is likely to be associated with more deleterious outcomes (e.g., greater severity of PTSD symptoms) than the same outcome in the absence of such distress. The individual's ability to cope with uncertainty may therefore determine their reaction to extreme harmful events, as well as their ability to psychologically adapt to such events. At the same time, the association of uncertainty with harmful outcomes may subsequently augment the individual's aversion for uncertainty. Behavioral economics analysis suggests that behavior under uncertainty is affected by the individual's weighting of two separate factors: (1) risk attitude, which reflects a trade-of between the probabilities of gains or losses, and the magnitude of those gains and losses~ and (2) ambiguity attitude, which reflects an individual's sensitivity to missing information about these probabilities. Neuroeconomics studies show that risk and ambiguity attitudes are reflected in the neural activation in regions of the medial prefrontal cortex (MPFC), the striatum and the amygdala, all areas that have been implicated in valuation processes in general. Intriguingly, these very same areas show structural and functional abnormalities in PTSD. In this proposal, we aim to characterize behavior under uncertainty and its neural correlates in trauma survivors with and without PTSD and healthy controls with no trauma experience. We hypothesize that individuals with PTSD will be more averse to ambiguity, and that trauma controls will be less averse to ambiguity compared to non-trauma-exposed controls. We further hypothesize that in individuals with PTSD activity in valuation areas, which normally reflects attitudes towards risk and ambiguity will cease to do so under conditions of ambiguous losses. We plan to test these hypotheses using a combination of functional MRI and experimental economics behavioral methods.

描述（由申请人提供）：创伤后应激障碍（PTSD）影响了很大比例的人口，一般人口的估计范围为6.4％至6.8％。迄今为止，没有生物学标记来识别有PTSD风险的个体，并且可用的治疗只能部分成功。 了解PTSD发展和维持的基础的行为和神经机制对于为了提高和完善旨在改善患者生活质量的行为和药物治疗干预措施而言，重要的是，最初是防止该疾病的。在PTSD背景下，MST创伤的一个方面是高度不良情况的高度不确定性。例如，在战场上，士兵们意识到对自己和他人的各种危险，但很少能够估计实现这些危险的可能性。在没有这种困扰的情况下，不良结果与不确定性困扰相比，可能与更有害的结果（例如，PTSD症状的严重程度更大）有关。因此，个人应对不确定性的能力可能决定了他们对极端有害事件的反应，以及他们在心理上适应此类事件的能力。同时，不确定性与有害结果的关联可能随后增加个人对不确定性的厌恶。行为经济学分析表明，不确定性下的行为受到个人对两个不同因素的加权的影响：（1）风险态度，这反映了收益或损失的概率之间的用处，以及这些损益和损失的幅度〜和（2）模棱两可的态度，这反映了个人对这些概率缺失信息的敏感性。神经经济学研究表明，风险和歧义态度反映在内侧前额叶皮层（MPFC），纹状体和杏仁核区域的神经激活中，这在总体评估过程中都涉及所有涉及的领域。有趣的是，这些相同的区域在PTSD中显示出结构和功能异常。在此提案中，我们旨在表征不确定性下的行为及其在具有PTSD和没有创伤经验的健康对照的创伤幸存者中的神经相关性。我们假设患有PTSD的个体将更厌恶歧义，而与非创伤性的对照相比，创伤控制措施对歧义的厌恶性较小。我们进一步假设，在估值领域具有PTSD活动的个体中，通常反映对风险和歧义的态度将在模棱两可的损失条件下停止这样做。我们计划使用功能性MRI和实验经济学行为方法的组合来检验这些假设。