Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720;
Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218.
Proc Natl Acad Sci U S A. 2020 Nov 3;117(44):27731-27739. doi: 10.1073/pnas.2008530117. Epub 2020 Oct 20.
People tend to interpret political information in a manner that confirms their prior beliefs, a cognitive bias that contributes to rising political polarization. In this study, we combined functional magnetic resonance imaging with semantic content analyses to investigate the neural mechanisms that underlie the biased processing of real-world political content. We scanned American participants with conservative-leaning or liberal-leaning immigration attitudes while they watched news clips, campaign ads, and public speeches related to immigration policy. We searched for evidence of "neural polarization": activity in the brain that diverges between people who hold liberal versus conservative political attitudes. Neural polarization was observed in the dorsomedial prefrontal cortex (DMPFC), a brain region associated with the interpretation of narrative content. Neural polarization in the DMPFC intensified during moments in the videos that included risk-related and moral-emotional language, highlighting content features most likely to drive divergent interpretations between conservatives and liberals. Finally, participants whose DMPFC activity closely matched that of the average conservative or the average liberal participant were more likely to change their attitudes in the direction of that group's position. Our work introduces a multimethod approach to study the neural basis of political cognition in naturalistic settings. Using this approach, we characterize how political attitudes biased information processing in the brain, the language most likely to drive polarized neural responses, and the consequences of biased processing for attitude change. Together, these results shed light on the psychological and neural underpinnings of how identical information is interpreted differently by conservatives and liberals.
人们倾向于以符合其先前信念的方式来解释政治信息，这种认知偏差导致了政治分歧的加剧。在这项研究中，我们结合功能磁共振成像和语义内容分析，研究了导致对现实政治内容产生偏见处理的神经机制。我们扫描了具有保守倾向或自由倾向移民态度的美国参与者，同时让他们观看与移民政策相关的新闻片段、竞选广告和公开演讲。我们寻找“神经极化”的证据：即具有自由和保守政治态度的人之间大脑活动的差异。在与解释叙述性内容相关的背内侧前额叶皮层（DMPFC）中观察到了神经极化。当视频中包含与风险相关和道德情感的语言时，DMPFC 中的神经极化加剧，突出了最有可能导致保守派和自由派之间不同解释的内容特征。最后，DMPFC 活动与平均保守派或平均自由派参与者的活动密切匹配的参与者更有可能朝着该群体立场的方向改变自己的态度。我们的工作介绍了一种在自然环境中研究政治认知神经基础的多方法方法。使用这种方法，我们描述了政治态度如何在大脑中对信息处理产生偏见，以及最有可能引发极化神经反应的语言，以及偏见处理对态度改变的后果。这些结果共同揭示了相同信息如何被保守派和自由派以不同方式解释的心理和神经基础。
