Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York.
Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2018 Apr;3(4):367-378. doi: 10.1016/j.bpsc.2017.11.011. Epub 2017 Dec 8.
Social discrimination, a type of psychological stressor, is associated with poorer physical and mental health outcomes, yet we have little understanding of how discrimination affects neural functions in marginalized populations. By contrast, the effects of psychological stress on neural functions are well documented, with evidence of significant effects on the amygdala-a neural region that is central to psychosocial functions. Accordingly, we conducted an examination of the relation between self-reported discrimination exposure and amygdala activity in a diverse sample of adults.
Seventy-four adults (43% women; 72% African American; 23% Hispanic; 32% homosexual/bisexual) completed self-report ratings of discrimination exposure. Spontaneous amygdala activity and functional connectivity were assessed during resting-state functional magnetic resonance imaging.
Greater discrimination exposure was associated with higher levels of spontaneous amygdala activity. Increases in discrimination were also associated with stronger functional connectivity between the amygdala and several neural regions (e.g., anterior insula, putamen, caudate, anterior cingulate, medial frontal gyrus), with the most robust effects observed in the thalamus. These effects were independent of several demographic (e.g., race, ethnicity, sex) and psychological (e.g., current stress, depression, anxiety) factors.
Collectively, our findings provide the first evidence that social discrimination is independently associated with elevations in intrinsic amygdala activity and functional connectivity, thus revealing clear parallels between the neural substrates of discrimination and psychological stressors of other origins. Such results should spur future investigations of amygdala-based networks as potential etiological factors linking discrimination exposure to adverse physical and mental health outcomes.
社会歧视是一种心理压力源，与较差的身心健康结果相关，但我们对歧视如何影响边缘化人群的神经功能知之甚少。相比之下，心理压力对神经功能的影响已有充分的记录，有证据表明其对杏仁核（一个对社会心理功能至关重要的神经区域）有重大影响。因此，我们在一个多样化的成年人样本中，考察了自我报告的歧视暴露与杏仁核活动之间的关系。
74 名成年人（43%为女性；72%为非裔美国人；23%为西班牙裔；32%为同性恋/双性恋）完成了歧视暴露的自我报告评分。在静息态功能磁共振成像期间评估了杏仁核的自发活动和功能连接。
更多的歧视暴露与更高水平的杏仁核自发活动相关。歧视的增加也与杏仁核和几个神经区域（例如前岛叶、壳核、尾状核、前扣带回、内侧额回）之间的功能连接增强有关，其中在丘脑观察到的影响最大。这些影响独立于几个人口统计学因素（例如种族、民族、性别）和心理因素（例如当前压力、抑郁、焦虑）。
总的来说，我们的研究结果首次提供了证据，表明社会歧视与杏仁核活动和功能连接的升高独立相关，从而揭示了歧视和其他来源的心理压力源的神经基质之间的明显相似性。这些结果应该促使未来对基于杏仁核的网络进行研究，作为将歧视暴露与不良身心健康结果联系起来的潜在病因因素。
