Investigating the effects of aversive interoceptive states on computations underlying avoidance behavior and their neural basis

焦虑症是最普遍的精神疾病形式，影响了大约34%的人口。一 保持焦虑症状的主要因素是继续避免令人恐惧的情况，事实上 可以忍受，而且通常会提高生活质量。然而，目前尚不清楚厌恶的内感状态是如何 与高度焦虑相关的影响不良回避行为的神经基础 这些影响就是。为了回答这些问题，我们建议采用先前验证的吸气式 呼吸负荷模式能够在个体完成两种状态时可靠地诱导厌恶的内脏状态 决策任务。我们将使用计算建模来确定潜在的可分离参数 在个人的基础上学习和决策。可以估计的一些重要的个体差异 在这些模型中，参数值反映：(1)寻求在多大程度上推动了决策 信息与报酬，以及(2)个人在做出决策时考虑的未来时间(计划 地平线)。这些参数的异常值可能会导致焦虑患者的不良适应回避行为 人群，因为学习接近令人不适的情况需要寻求信息(测试 预期)和足够的计划范围，以预见短期的不适可能导致长期的 利益。在这里，我们假设厌恶的本能状态会减少信息寻求，缩短计划 地平线。我们进一步假设，这些影响在焦虑的人群中被放大。在这个项目中将招聘 50名低焦虑和50名高焦虑参与者(总体焦虑严重程度和损害量表[OASIS]评分为8分)至 检验上述假设。参与者将完成两项广泛使用的决策任务 计算模型-厌恶修剪(AP)任务6，7和地平线任务8。它们将分别完成 任务两次，一次带着令人不快的呼吸负荷，一次没有。AP任务评估厌恶决策 真正的‘修剪’-如果近端为阴性，则不评估可能的行动方案的远端结果的倾向 预期结果(即有效地缩短了可能具有积极影响的政策的规划范围 结果)。地平线任务评估目标导向的信息寻求--战略性寻求的倾向 在对最好的行动方案充满信心之前，先进行观察以减少不确定性。AP任务将 在功能磁共振成像期间完成。我们将比较信息查找和修剪参数值与不使用参数值的情况 呼吸负荷，并将这些参数与状态和特质焦虑水平相关。我们还将检验这一假设 呼吸负荷期间的厌恶状态将通过增加 膝下扣带核、脑岛核和杏仁核的神经反应与额顶背侧活动减少 与未来规划相关的。确定厌恶状态促进回避的机制将是 这是设计针对这些机制和改善症状的新干预措施的重要第一步。

Anxiety disorders are the most ubiquitous form of mental illness, affecting roughly 34% of the population. One major factor that maintains anxiety symptoms is the continued avoidance of feared situations that are in fact tolerable and would often improve quality of life. However, it is unknown how the aversive interoceptive states associated with high anxiety influence maladaptive avoidance behavior – or what the neural underpinnings of such influences are. To answer these questions, we propose to employ a previously validated inspiratory breathing load paradigm capable of reliably inducing aversive visceral states while individuals complete two decision-making tasks. We will use computational modeling to identify dissociable parameters underlying learning and decision-making on an individual basis. Some important individual differences that can be estimated within these models are values of parameters reflecting: (1) how much decisions are driven by seeking information vs. reward, and (2) how far into the future an individual considers when making decisions (planning horizon). Abnormal values for these parameters could drive maladaptive avoidance behavior in anxious populations, because learning to approach uncomfortable situations requires both information-seeking (to test expectations) and a sufficient planning horizon to anticipate that short-term discomfort can lead to long-term benefit. Here we hypothesize that aversive visceral states reduce information-seeking and shorten planning horizon. We further hypothesize that these effects are magnified in anxious populations. In this project will recruit 50 low- and 50 high-anxiety participants (Overall Anxiety Severity and Impairment Scale [OASIS] scores > 8) to test the above-stated hypotheses. Participants will complete two decision-making tasks widely used with computational modelling – the aversive pruning (AP) task 6,7 and the horizon task 8. They will complete each task twice, once with and once without the unpleasant breathing load. The AP task assesses aversive decision true ‘pruning’ – the tendency to not evaluate distal outcomes of a possible course of action if a proximal negative outcome is expected (i.e. effectively reducing planning horizon for policies that may have positive distal outcomes). The horizon task assesses goal-directed information-seeking – the tendency to strategically seek out observations to reduce uncertainty before becoming confident in the best course of action. The AP task will be completed during fMRI. We will compare information-seeking and pruning parameter values with vs. without breathing loads and correlate these parameters with state and trait anxiety levels. We will also test the hypothesis that aversive states during breathing load will amplify the known neural correlates of pruning, by increasing neural responses in subgenual cingulate, insula, and amygdala and reducing dorsal frontoparietal activity associated with future planning. Identifying the mechanisms by which aversive states promote avoidance will be an important first step toward designing new interventions to target these mechanisms and improve symptoms.