Transient Neural Activation in Human Amygdala Involved in Aversive Conditioning of Face and Voice
Transient Neural Activation in Human Amygdala Involved in Aversive Conditioning of Face and Voice
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DOI：
10.1162/jocn.2009.21347
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发表时间：
2010-09-01
影响因子：
3.2
通讯作者：
Sadato, Norihiro
中科院分区：
文献类型：
--
作者：
Iidaka, Tetsuya;Saito, Daisuke N.;Sadato, Norihiro
阐明厌恶性条件反射所涉及的神经机制有助于找到治疗焦虑症和恐惧症等精神疾病的有效方法。之前使用功能磁共振成像和人类受试者的研究表明，杏仁核在这一现象中发挥了作用。然而，在以前的研究中用作无条件刺激的有害刺激（例如电击）可能在生态上是无效的，因为我们在日常生活中很少遇到这种刺激。因此，我们研究了是否可以通过使用从现实生活环境中收集的具有负面情绪效价的声音来调节面部刺激。皮肤电导反应表明，健康受试者通过使用这些刺激进行了调节。在一项功能磁共振成像研究中，与未与声音配对的面孔相比，与声音配对的面孔相比，杏仁核的激活程度更高。右侧杏仁核在习得的早期表现出短暂的活动。心理生理学相互作用分析表明，从内侧膝状体到杏仁核的皮质下通路在调节中发挥作用。声音刺激对皮质下通路的调节先于杏仁核的短暂活动。研究发现，生态上有效的刺激会引发条件反射和杏仁核反应，这表明我们的大脑正在自动处理日常生活中不愉快的刺激。
Elucidating the neural mechanisms involved in aversive conditioning helps find effective treatments for psychiatric disorders such as anxiety disorder and phobia. Previous studies using fMRI and human subjects have reported that the amygdala plays a role in this phenomenon. However, the noxious stimuli that were used as unconditioned stimuli in previous studies (e. g., electric shock) might have been ecologically invalid because we seldom encounter such stimuli in daily life. Therefore, we investigated whether a face stimulus could be conditioned by using a voice that had negative emotional valence and was collected from a real-life environment. A skin conductance response showed that healthy subjects were conditioned by using these stimuli. In an fMRI study, there was greater amygdala activation in response to the faces that had been paired with the voice than to those that had not. The right amygdala showed transient activity in the early stage of acquisition. A psychophysiological interaction analysis indicated that the subcortical pathway from the medial geniculate body to the amygdala played a role in conditioning. Modulation of the subcortical pathway by voice stimuli preceded the transient activity in the amygdala. The finding that an ecologically valid stimulus elicited the conditioning and amygdala response suggests that our brain is automatically processing unpleasant stimuli in daily life.