A Neurocomputational Account of How Inflammation Enhances Sensitivity to Punishments Versus Rewards.
A Neurocomputational Account of How Inflammation Enhances Sensitivity to Punishments Versus Rewards.
复制标题
关于炎症如何增强对惩罚与奖励的敏感性的神经计算说明。
DOI：
10.1016/j.biopsych.2015.07.018
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发表时间：
2016-07-01
影响因子：
10.6
通讯作者：
Critchley HD
中科院分区：
文献类型：
--
作者：
Harrison NA;Voon V;Cercignani M;Cooper EA;Pessiglione M;Critchley HD
炎症会迅速损害情绪和认知，严重时，可能与重度抑郁症难以区分。这些疾病反应的特征是动机状态的急性重新定向;避免愉快的活动，并增强对负面刺激的敏感性。然而，目前还不清楚这些行为的快速转变是如何在大脑中介导的。在这里，我们结合了选择行为的计算建模，实验诱导的炎症和功能性脑成像（功能性磁共振成像）来描述这些机制。采用双盲、随机交叉研究设计，24名健康志愿者在两个不同的场合完成了概率工具学习任务，一个是伤寒疫苗接种后3小时，另一个是盐水（安慰剂）注射后3小时。参与者学习选择高概率奖励（赢得1英镑）和避免高概率惩罚（失去1英镑）刺激。一个动作值学习算法适合观察到的行为，然后在功能磁共振成像分析中使用，以识别驱动动机学习的预测错误信号的神经编码。炎症急性偏见的行为，增强惩罚相比，奖励的敏感性，通过不同的行动对神经表征的奖励和惩罚的预测错误的腹侧纹状体和前额叶。因此，导致潜在奖励的选择在行为上不那么吸引人，而导致惩罚的选择则更令人厌恶。我们的研究结果表明，在炎症过程中，奖励与惩罚敏感性的快速，状态依赖性重新定位的神经介导。这种机制可能有助于急性疾病期间代谢资源的适应性重新分配，但也可能解释适应不良的动机变化，这些变化是慢性炎症和抑郁症之间联系的基础。
Inflammation rapidly impairs mood and cognition and, when severe, can appear indistinguishable from major depression. These sickness responses are characterized by an acute reorientation of motivational state; pleasurable activities are avoided, and sensitivity to negative stimuli is enhanced. However, it remains unclear how these rapid shifts in behavior are mediated within the brain. Here, we combined computational modeling of choice behavior, experimentally induced inflammation, and functional brain imaging (functional magnetic resonance imaging) to describe these mechanisms. Using a double-blind, randomized crossover study design, 24 healthy volunteers completed a probabilistic instrumental learning task on two separate occasions, one 3 hours after typhoid vaccination and one 3 hours after saline (placebo) injection. Participants learned to select high probability reward (win £1) and avoid high probability punishment (lose £1) stimuli. An action-value learning algorithm was fit to the observed behavior, then used within functional magnetic resonance imaging analyses to identify neural coding of prediction error signals driving motivational learning. Inflammation acutely biased behavior, enhancing punishment compared with reward sensitivity, through distinct actions on neural representations of reward and punishment prediction errors within the ventral striatum and anterior insula. Consequently, choice options leading to potential rewards were less behaviorally attractive, and those leading to punishments were more aversive. Our findings demonstrate the neural mediation of a rapid, state-dependent reorientation of reward versus punishment sensitivity during inflammation. This mechanism may aid the adaptive reallocation of metabolic resources during acute sickness but might also account for maladaptive, motivational changes that underpin the association between chronic inflammation and depression.