University of Basel.
J Cogn Neurosci. 2020 Jun;32(6):1117-1129. doi: 10.1162/jocn_a_01537. Epub 2020 Feb 4.
The amygdala is critically involved in emotional processing, including fear responses, and shows hyperactivity in anxiety disorders. Previous research in healthy participants has indicated that amygdala activity is down-regulated by cognitively demanding tasks that engage the PFC. It is unknown, however, if such an acute down-regulation of amygdala activity might correlate with reduced fear in anxious participants. In an fMRI study of 43 participants (11 men) with fear of snakes, we found reduced amygdala activity when visual stimuli were processed under high cognitive load, irrespective of whether the stimuli were of neutral or phobic content. Furthermore, dynamic causal modeling revealed that this general reduction in amygdala activity was partially mediated by a load-dependent increase in dorsolateral PFC activity. Importantly, high cognitive load also resulted in an acute decrease in perceived phobic fear while viewing the fearful stimuli. In conclusion, our data indicate that a cognitively demanding task results in a top-down regulation of amygdala activity and an acute reduction of fear in phobic participants. These findings may inspire the development of novel psychological intervention approaches aimed at reducing fear in anxiety disorders.
杏仁核在情绪处理中起着至关重要的作用，包括恐惧反应，并且在焦虑障碍中表现出过度活跃。以前在健康参与者中的研究表明，杏仁核活动可以通过参与前额叶皮层的认知要求高的任务来下调。然而，尚不清楚这种杏仁核活动的急性下调是否与焦虑参与者的恐惧减少相关。在一项对 43 名（11 名男性）害怕蛇的参与者的 fMRI 研究中，我们发现当视觉刺激在高认知负荷下被处理时，杏仁核活动减少，而与刺激是中性还是恐惧症内容无关。此外，动态因果建模显示，这种杏仁核活动的普遍减少部分是由背外侧前额叶皮层活动的负荷依赖性增加介导的。重要的是，高认知负荷也导致在观看恐惧刺激时急性降低了恐惧症的恐惧。总之，我们的数据表明，认知要求高的任务会导致杏仁核活动的自上而下调节，并在恐惧症患者中急性降低恐惧。这些发现可能会激发旨在减少焦虑障碍中恐惧的新型心理干预方法的发展。
