Kokoro Research Center, Kyoto University.
School of Psychology and Public Health, La Trobe University.
J Exp Psychol Gen. 2016 Mar;145(3):273-83. doi: 10.1037/xge0000121. Epub 2015 Nov 16.
Reminders of death often elicit defensive responses in individuals, especially among those with low self-esteem. Although empirical evidence indicates that self-esteem serves as a buffer against mortality threats, the precise neural mechanism underlying this effect remains unknown. We used functional magnetic resonance imaging (fMRI) to test the hypothesis that self-esteem modulates neural responses to death-related stimuli, especially functional connectivity within the limbic-frontal circuitry, thereby affecting subsequent defensive reactions. As predicted, individuals with high self-esteem subjected to a mortality threat exhibited increased amygdala-ventrolateral prefrontal cortex (VLPFC) connectivity during the processing of death-related stimuli compared with individuals who have low self-esteem. Further analysis revealed that stronger functional connectivity between the amygdala and the VLPFC predicted a subsequent decline in responding defensively to those who threaten one's beliefs. These results suggest that the amygdala-VLPFC interaction, which is modulated by self-esteem, can reduce the defensiveness caused by death-related stimuli, thereby providing a neural explanation for why individuals with high self-esteem exhibit less defensive reactions to mortality threats.
死亡提醒常常会引发个体的防御反应，尤其是那些自尊心较低的个体。尽管实证研究表明，自尊心可以缓冲对死亡威胁的反应，但这一效应背后的确切神经机制尚不清楚。我们使用功能磁共振成像（fMRI）来验证假设，即自尊心会调节个体对与死亡相关的刺激的神经反应，尤其是调节边缘-额皮质回路内的功能连接，从而影响随后的防御反应。正如预测的那样，与自尊心较低的个体相比，受到死亡威胁的自尊心较高的个体在处理与死亡相关的刺激时，杏仁核-腹外侧前额叶皮质（VLPFC）的连接增加。进一步的分析表明，杏仁核和 VLPFC 之间更强的功能连接预示着对那些威胁到自己信念的人做出防御性反应的后续下降。这些结果表明，受自尊心调节的杏仁核-VLPFC 相互作用可以减少与死亡相关的刺激引起的防御反应，从而为为什么自尊心较高的个体对死亡威胁表现出较少的防御反应提供了神经学解释。
