Tashjian Sarah M, Cussen Joseph, Deng Wenning, Zhang Bo, Mobbs Dean
School of Psychological Sciences, University of Melbourne, Parkville, Australia.
Humanities and Social Sciences, California Institute of Technology, Pasadena, California, United States of America.
PLoS Biol. 2025 Jan 13;23(1):e3002986. doi: 10.1371/journal.pbio.3002986. eCollection 2025 Jan.
Pivotal to self-preservation is the ability to identify when we are safe and when we are in danger. Previous studies have focused on safety estimations based on the features of external threats and do not consider how the brain integrates other key factors, including estimates about our ability to protect ourselves. Here, we examine the neural systems underlying the online dynamic encoding of safety. The current preregistered study used 2 novel tasks to test 4 facets of safety estimation: Safety Prediction, Meta-representation, Recognition, and Value Updating. We experimentally manipulated safety estimation changing both levels of external threats and self-protection. Data were collected in 2 independent samples (behavioral N = 100; MRI N = 30). We found consistent evidence of subjective changes in the sensitivity to safety conferred through protection. Neural responses in the ventromedial prefrontal cortex (vmPFC) tracked increases in safety during all safety estimation facets, with specific tuning to protection. Further, informational connectivity analyses revealed distinct hubs of safety coding in the posterior and anterior vmPFC for external threats and protection, respectively. These findings reveal a central role of the vmPFC for coding safety.
自我保护的关键在于能够识别我们何时安全、何时处于危险之中。以往的研究主要集中在基于外部威胁特征的安全评估上，并未考虑大脑如何整合其他关键因素，包括对我们自我保护能力的评估。在此，我们研究了安全在线动态编码背后的神经系统。当前这项预先注册的研究使用了两项新任务来测试安全评估的四个方面：安全预测、元表征、识别和价值更新。我们通过实验操纵安全评估，改变外部威胁和自我保护的水平。数据收集于两个独立样本（行为学样本N = 100；磁共振成像样本N = 30）。我们发现了一致的证据，表明通过保护赋予的对安全的敏感性存在主观变化。在所有安全评估方面，腹内侧前额叶皮层（vmPFC）的神经反应都跟踪了安全性的增加，并对保护进行了特定的调整。此外，信息连通性分析分别揭示了vmPFC后部和前部针对外部威胁和保护的不同安全编码中心。这些发现揭示了vmPFC在编码安全方面的核心作用。
