Section on the Neurobiology of Fear and Anxiety, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
Psychophysiology. 2011 Dec;48(12):1745-52. doi: 10.1111/j.1469-8986.2011.01268.x. Epub 2011 Aug 8.
Fearful faces readily activate the amygdala. Yet, whether fearful faces evoke fear is unclear. Startle studies show no potentiation of startle by fearful faces, suggesting that such stimuli do not activate defense mechanisms. However, the response to biologically relevant stimuli may be sensitized by anxiety. The present study tested the hypothesis that startle would not be potentiated by fearful faces in a safe context, but that startle would be larger during fearful faces compared to neutral faces in a threat-of-shock context. Subjects viewed fearful and neutral faces in alternating periods of safety and threat of shock. Acoustic startle stimuli were presented in the presence and absence of the faces. Startle was transiently potentiated by fearful faces compared to neutral faces in the threat periods. This suggests that although fearful faces do not prompt behavioral mobilization in an innocuous context, they can do so in an anxiogenic one.
恐惧的面孔很容易激活杏仁核。然而，恐惧的面孔是否会引起恐惧尚不清楚。惊跳研究表明，恐惧的面孔不会增强惊跳反应，这表明这些刺激不会激活防御机制。然而，对生物相关刺激的反应可能会因焦虑而变得敏感。本研究假设在安全的环境中，惊跳不会因恐惧的面孔而增强，但在受到电击威胁的环境中，与中性面孔相比，恐惧的面孔会引起更大的惊跳反应。实验对象在安全和受到电击威胁的环境中交替观看恐惧和中性面孔。在有和没有面孔的情况下呈现听觉惊跳刺激。与中性面孔相比，在受到电击威胁的环境中，恐惧的面孔会使惊跳反应暂时增强。这表明，尽管恐惧的面孔在无害的环境中不会引起行为动员，但在焦虑的环境中可能会引起行为动员。
