基于知觉的恐惧泛化的认知神经机制

恐惧泛化是条件性恐惧反应转移到另一个相似但安全的刺激的现象。适当的恐惧泛化对人类有积极意义, 而过度的恐惧泛化则不利于个体有效地适应环境。基于知觉的恐惧泛化研究揭示了恐惧泛化的规律, 因而被广泛应用。本文首先梳理了对知觉恐惧泛化的相关研究, 介绍恐惧泛化的经典理论基础—巴普洛夫条件反射以及恐惧泛化梯度; 其次简要回顾基于多个感觉通道(即视觉、听觉、情景)的知觉恐惧泛化研究现状; 再次, 分别对海马、杏仁核、脑岛和前额叶等脑区在恐惧泛化中的作用进行回顾, 进一步总结出恐惧泛化的神经环路结构模型。最后, 简要区分了基于知觉的恐惧泛化和正在兴起的基于概念的恐惧泛化, 进而指出未来研究需要结合基于概念的恐惧泛化、区分被试对刺激的辨别力、增加恐惧刺激材料的准确性及多样化、结合激素等个体差异和多模态脑成像数据来展开。

The neural mechanism of fear generalization based on perception

Fear generalization is a phenomenon that conditioned fear responses extended to safe stimuli which shares perceptual similarity with threat stimuli. Moderate fear generalization is beneficial for human survival, but excessive fear generalization leads to maladaptation to environment. Rules that underlie fear generalization have been investigated by related researches based on perception, and been widely applied to studies in various domains. This paper reviews the study of the generalization of fear based on perception. Here, we begin with Pavlovian fear conditioning and the gradient of fear generalization, which lays the foundation for theoretical approaches used today. Then we review the research of fear generalization based on perception in multiple sensory channels (i.e., visual, auditory, context). Third, we summarize the neural circuits of fear generalization which involve hippocampus, amygdala, insula, and prefrontal cortex. Last but not least, we briefly clarify the difference between perception-based and concept-based fear generalization which receive increased interests. Further studies should extend this work in many ways, such as combining concepts-based fear generalization, using Just-Noticeable-Difference Threshold to ensure that the generalization stimuli can actually be discriminated, increasing the explicitness and divisity of stimuli, as well as applping hormonesand multi-modal data analysis methods.