Computation and Neural Systems, California Institute of Technology, Pasadena, California 91125, USA.
Humanities and Social Sciences, California Institute of Technology, Pasadena, California 91125, USA.
Nat Commun. 2017 Apr 21;8:14821. doi: 10.1038/ncomms14821.
The human amygdala is a key structure for processing emotional facial expressions, but it remains unclear what aspects of emotion are processed. We investigated this question with three different approaches: behavioural analysis of 3 amygdala lesion patients, neuroimaging of 19 healthy adults, and single-neuron recordings in 9 neurosurgical patients. The lesion patients showed a shift in behavioural sensitivity to fear, and amygdala BOLD responses were modulated by both fear and emotion ambiguity (the uncertainty that a facial expression is categorized as fearful or happy). We found two populations of neurons, one whose response correlated with increasing degree of fear, or happiness, and a second whose response primarily decreased as a linear function of emotion ambiguity. Together, our results indicate that the human amygdala processes both the degree of emotion in facial expressions and the categorical ambiguity of the emotion shown and that these two aspects of amygdala processing can be most clearly distinguished at the level of single neurons.
人类杏仁核是处理情绪面部表情的关键结构，但对于杏仁核处理哪些方面的情绪仍不清楚。我们通过三种不同的方法来研究这个问题：对 3 名杏仁核损伤患者的行为分析、对 19 名健康成年人的神经影像学研究以及对 9 名神经外科患者的单细胞记录。损伤患者在行为上对恐惧的敏感性发生了转变，并且杏仁核的 BOLD 反应既受到恐惧的调节，也受到情绪模糊性（即对面部表情归类为恐惧或快乐存在不确定性）的调节。我们发现了两种神经元群体，一种的反应与恐惧或快乐程度的增加相关，另一种的反应主要作为情绪模糊性的线性函数而减少。总的来说，我们的研究结果表明，人类杏仁核处理面部表情的情绪程度和情绪表现的类别模糊性，并且这两个方面的杏仁核处理可以在单细胞水平上最清晰地区分开来。
