Cikara Mina, Van Bavel Jay J, Ingbretsen Zachary A, Lau Tatiana
Department of Psychology, Harvard University.
Department of Psychology, New York University.
J Exp Psychol Gen. 2017 May;146(5):621-631. doi: 10.1037/xge0000287.
Humans form social coalitions in every society on earth, yet we know very little about how the general concepts us and them are represented in the brain. Evolutionary psychologists have argued that the human capacity for group affiliation is a byproduct of adaptations that evolved for tracking coalitions in general. These theories suggest that humans possess a common neural code for the concepts in-group and out-group, regardless of the category by which group boundaries are instantiated. The authors used multivoxel pattern analysis to identify the neural substrates of generalized group concept representations. They trained a classifier to encode how people represented the most basic instantiation of a specific social group (i.e., arbitrary teams created in the lab with no history of interaction or associated stereotypes) and tested how well the neural data decoded membership along an objectively orthogonal, real-world category (i.e., political parties). The dorsal anterior cingulate cortex/middle cingulate cortex and anterior insula were associated with representing groups across multiple social categories. Restricting the analyses to these regions in a separate sample of participants performing an explicit categorization task, the authors replicated cross-categorization classification in anterior insula. Classification accuracy across categories was driven predominantly by the correct categorization of in-group targets, consistent with theories indicating in-group preference is more central than out-group derogation to group perception and cognition. These findings highlight the extent to which social group concepts rely on domain-general circuitry associated with encoding stimuli's functional significance. (PsycINFO Database Record
在地球上的每个社会中，人类都会形成社会联盟，但我们对大脑中如何表征“我们”和“他们”这些一般概念却知之甚少。进化心理学家认为，人类的群体归属能力是为总体追踪联盟而进化出的适应性的副产品。这些理论表明，无论群体边界是通过何种类别来体现的，人类对于内群体和外群体概念都拥有一种共同的神经编码。作者使用多体素模式分析来识别广义群体概念表征的神经基础。他们训练了一个分类器，以编码人们如何表征特定社会群体的最基本体现（即实验室中创建的、没有互动历史或相关刻板印象的任意团队），并测试神经数据沿着一个客观正交的现实世界类别（即政党）解码成员身份的能力。背侧前扣带回皮质/中扣带回皮质和前脑岛与跨多个社会类别的群体表征有关。在执行明确分类任务的另一组参与者中，将分析限制在这些区域，作者在前脑岛中重复了跨类别分类。跨类别的分类准确率主要由对内群体目标的正确分类驱动，这与表明内群体偏好比外群体贬低在群体感知和认知中更核心的理论一致。这些发现凸显了社会群体概念在多大程度上依赖于与编码刺激功能意义相关的领域通用神经回路。（《心理学文摘数据库记录》 ）
