Department of Psychiatry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5A5, Canada.
Behav Brain Res. 2013 Sep 1;252:396-404. doi: 10.1016/j.bbr.2013.06.010. Epub 2013 Jun 13.
There are two current models of amygdala functioning with regard to identification of emotional expression. Classic models propose that the amygdala contributes to emotional expression recognition and empathy by encoding the level of threat or distress, and as such, responds greatest to more potent fearful cues. However, recent evidence suggests that the amygdala directs attention to relevant object features to disambiguate the stimulus (e.g., the eyes of a fearful face). The present study used fMRI to investigate amygdala functioning during the perception and identification of emotion in complex visual scenes. Participants later rated the images on levels of fear, disgust and arousal. These ratings were used to identify stimuli that were emotionally-ambiguous, emotionally-discrete, and non-emotional for each individual. A whole-brain and ROI approach was used to identify the nature of the amygdala response to visual scenes. Amygdala activity was associated with higher levels of fear in stimuli and was found to reflect the level of arousal in complex visual scenes. In contrast, no activity was observed that would indicate that the amygdala was modulated by emotional ambiguity when discriminating between fearful and disgusting visual scenes. These results are consistent with models that implicate the amygdala in the evaluation and representation of the intensity of fear, and imply that the functional contribution of the amygdala to deciphering threat in visual scenes likely extends beyond the search for emotionally salient features. The results also suggest that using attention to remedy emotion recognition abnormalities in at-risk populations with amygdala dysfunction may not address all key deficits associated with contributions of the amygdala to emotion and empathy.
目前有两种关于杏仁核在识别情绪表达方面的功能模型。经典模型提出，杏仁核通过编码威胁或痛苦的程度，有助于情绪表达识别和同理心，因此，对更强烈的恐惧线索反应最大。然而，最近的证据表明，杏仁核引导注意力关注相关的物体特征，以消除刺激的歧义（例如，恐惧面孔的眼睛）。本研究使用 fMRI 研究了杏仁核在复杂视觉场景中感知和识别情绪时的功能。参与者随后对图像的恐惧、厌恶和唤醒程度进行评分。这些评分用于识别每个个体的情绪模糊、情绪离散和非情绪刺激。采用全脑和 ROI 方法来识别杏仁核对视觉场景反应的性质。杏仁核活动与刺激中的恐惧水平较高有关，并且被发现反映了复杂视觉场景中的唤醒水平。相比之下，在区分恐惧和厌恶的视觉场景时，没有观察到表明杏仁核受情绪模糊性调节的活动。这些结果与涉及杏仁核在评估和表示恐惧强度的模型一致，并暗示杏仁核对视觉场景中威胁的解读的功能贡献可能超出了对情感显著特征的搜索。结果还表明，使用注意力来纠正杏仁核功能障碍的高危人群的情绪识别异常，可能无法解决与杏仁核对情绪和同理心的贡献相关的所有关键缺陷。
