Department of Psychology and Neuroscience, DePauw University, Greencastle, IN 46135, USA; Department of Psychology, University of Maryland, College Park, MD 20742, USA; Department of Human Development, Cornell University, Ithaca, NY 14850, USA; Human Neuroscience Institute, Cornell University, Ithaca, NY 14850, USA.
Neuropsychologia. 2018 Aug;117:566-573. doi: 10.1016/j.neuropsychologia.2018.07.004. Epub 2018 Jul 4.
Emotion studies show that ventromedial prefrontal cortex (vmPFC) plays a critical role in negative affect evaluation. Here we investigated two questions: Does the neural sensitivity to threat of bodily harm in vmPFC alter as anxiety levels increase? If the neural sensitivity to threat in vmPFC reflects a kind of general emotional processing, does it predict reward processing? To address these questions, we first recorded participants' self-reported anxiety. In an investigation of neural responses in vmPFC (Session 1), we measured brain activity (fMRI) associated with the anticipation of threat, using a sphere based ROI approach. In a behavioral experiment (Session 2), participants' reward processing efficiency was evaluated when they performed a visual discrimination task in which they had the opportunity to earn cash rewards. We found that across participants, there were tightly coupled associations between signal changes in the vmPFC and self-reported state anxiety. Specifically, participants who showed more activation in vmPFC to threat also exhibited greater behavioral efficiency in reward processing. Path analysis revealed a closely interconnected network of vmPFC (cortical) and VS (ventral striatum, subcortical) which predicted reward processing. Therefore, in addition to negative affect evaluation, neural sensitivity in vmPFC correlated with both anxiety and reward-related metrics. These results support an emerging model in which the vmPFC functions to defend the organism from acute stress and facilitate reward processes.
情绪研究表明，腹内侧前额叶皮层（vmPFC）在负性情绪评估中起着关键作用。在这里，我们研究了两个问题：随着焦虑水平的增加，vmPFC 对身体伤害威胁的神经敏感性是否会改变？如果 vmPFC 对威胁的神经敏感性反映了一种一般的情绪处理，它是否可以预测奖励处理？为了解决这些问题，我们首先记录了参与者的自我报告焦虑。在 vmPFC 的神经反应研究中（第 1 期），我们使用基于球体的 ROI 方法测量了与威胁预期相关的大脑活动（fMRI）。在行为实验中（第 2 期），参与者在执行视觉辨别任务时评估了他们的奖励处理效率，在该任务中他们有机会获得现金奖励。我们发现，在所有参与者中，vmPFC 和自我报告的状态焦虑之间存在紧密耦合的信号变化关联。具体来说，vmPFC 对威胁的反应越强烈的参与者，在奖励处理方面的行为效率也越高。路径分析揭示了 vmPFC（皮质）和 VS（腹侧纹状体，皮质下）之间紧密相连的网络，该网络可以预测奖励处理。因此，除了负性情绪评估外，vmPFC 的神经敏感性还与焦虑和奖励相关的指标相关。这些结果支持了一个新兴模型，即 vmPFC 可以保护机体免受急性应激，并促进奖励过程。
