Williams Leanne M, Barton Matthew J, Kemp Andrew H, Liddell Belinda J, Peduto Anthony, Gordon Evian, Bryant Richard A
The Brain Dynamics Centre, Westmead Millenium Institute, Acacia House, Westmead Hospital, Westmead, NSW 2145, Australia.
Neuroimage. 2005 Nov 15;28(3):618-26. doi: 10.1016/j.neuroimage.2005.06.035. Epub 2005 Aug 2.
The amygdala has a key role in regulating arousal and vigilance, and responds to both visual and vocal signals of fear, including facial expressions of fear. In this study, we used functional MRI to examine sex differences in the magnitude, extent, lateralization and time course of amygdala responses to facial signals of fear, in a relatively large sample of males and females. Skin conductance was recorded simultaneously with functional imaging to examine concomitant changes in emotional arousal, and to provide an independent index of response attenuation. Scanning and skin conductance recording was undertaken during perception of facial fear stimuli. Sex differences were apparent in the laterality and time course of fear perception. In males, the right amygdala and autonomic arousal attenuated over the late half of the experiment. By contrast, females showed persistent bilateral amygdala responses, with a tendency towards greater left amygdala engagement during the late phase. Females also showed a greater general extent of amygdala response. We suggest that distinct evolutionary pressures might contribute to a lower threshold for vigilance to signals of danger in females, reflected in a profile of sustained amygdala-arousal interaction.
杏仁核在调节唤醒和警觉方面起着关键作用，并且对恐惧的视觉和声音信号都会做出反应，包括恐惧的面部表情。在本研究中，我们使用功能磁共振成像（fMRI），在相对大量的男性和女性样本中，研究杏仁核对恐惧面部信号反应的强度、范围、偏侧化和时间进程方面的性别差异。在功能成像的同时记录皮肤电传导，以检查情绪唤醒的伴随变化，并提供反应衰减的独立指标。在对面部恐惧刺激的感知过程中进行扫描和皮肤电传导记录。在恐惧感知的偏侧化和时间进程方面存在明显的性别差异。在男性中，右侧杏仁核和自主唤醒在实验后半段减弱。相比之下，女性表现出双侧杏仁核的持续反应，在后期阶段左侧杏仁核参与度有更高的趋势。女性还表现出杏仁核反应的总体范围更大。我们认为，不同的进化压力可能导致女性对危险信号的警觉阈值较低，这反映在持续的杏仁核 - 唤醒相互作用模式中。
