Studying the role of the human habenular system in social hierarchy

尽管我们的社会地位和等级通常决定了我们是谁，是我们日常生活(在家里、学校、工作等)不可或缺的一部分，但我们仍然对大脑如何处理关于社会等级的信息知之甚少。社会等级制度往往是通过社会冲突建立起来的，是一种普遍现象，在包括人类在内的社会物种的最佳运作中发挥着核心作用。重要的是，为了驾驭以社会等级为特征的社会环境，我们的大脑必须：识别社会冲突的结果--谁赢了/谁输了，从而获得了更高/更低的地位；学习和更新关于社会等级的信息；以及选择在社会等级背景下产生的最佳行动。这项研究计划旨在研究这些认知能力及其相互作用，以更好地了解支持社会等级制度的神经过程及其对行为和决策的影响。我们认为缰核在这三种能力中起着关键作用。缰核是上皮层的一个小的大脑结构，在认知和情感大脑系统之间起着枢纽的作用。*为了研究社会等级的神经基础及其对人类行为的影响，我们将使用一种创新的方法，将专门设计用于引发社会等级处理的行为任务与行为建模相结合-使用数学模型来描述个人如何做出决定。为了测量这些任务中的大脑活动，我们将使用高分辨率功能磁共振成像(FMRI)，该成像是为研究缰核等微小的大脑结构而量身定做的。我们将研究普通人群，更重要的是，研究在高度等级环境中工作的军事人员，因此非常适合研究与社会等级相关的短期和长期行为和神经变化。*这项研究计划将通过调查结果编码、学习和决策以及这些过程如何相互作用，为科学界提供关于社会等级过程的新的有价值的知识。重要的是，几种类型的组织(军事、应急部队、工业)依赖于必须孤立工作的小个人团体，在这些团体中必然会形成社会等级制度。这些小团队的充分运作一定程度上取决于每个成员如何处理社会等级制度。通过描述支持社会等级制度的大脑机制以及它们如何改变，这项研究计划将为旨在促进这些小团队最佳运作的培训的发展提供科学基础。

Although our social status and ranks often define who we are and are an integral part of our daily life (at home, at school, at work, etc.), we still know fairly little about how our brain processes information about social hierarchy. Social hierarchy, which is often established through social conflicts, is a universal phenomenon and plays a central role in optimal functioning of social species including humans. Importantly, to navigate social environments characterized by social hierarchy, our brain has to: identify the outcomes of social conflicts—who has won/lost and thus as gained higher/lower status; learn and update information about social hierarchy; and choose the best actions to produce in a social hierarchy context. This research program aims at studying each of these cognitive abilities and their interactions to gain a better understanding of the neural processes supporting social hierarchy and its influence on behavior and decision-making. We propose that the habenula, a small brain structure of the epithalamus that acts as a hub between cognitive and affective brain systems, plays a key role in these three abilities. ******To study the neural underpinnings of social hierarchy and its influence on human behavior, we will use an innovative approach combining behavioral tasks specifically designed to elicit social hierarchy processing and behavioral modeling—the use of mathematical models to describe how individuals make decisions. To measure brain activity during these tasks, we will use high-resolution functional magnetic resonance imaging (fMRI) tailored for the study of small brain structures such as the habenula. We will study the general population and, importantly, military personnel who work in highly hierarchical contexts and are thus ideally suited to investigate short and long term behavioral and neural changes related to social hierarchy.******This research program will provide the scientific community with new and valuable knowledge about the processing of social hierarchy by investigating outcome coding, learning and decision-making and how these processes interact. Importantly, several types of organizations (military, emergency units, industry) rely on small groups of individuals that have to work in isolation and in which social hierarchies are bound to be formed. Adequate functioning of these small teams surely depends in part on how each member processes social hierarchy. By describing the brain mechanisms that support social hierarchy and how they can change, this research program will provide scientific bases for the development of training aimed at favoring optimal functioning in these small teams.