Social aspects of restrictive eating behavior in anorexia nervosa

计划中的项目的目的是增加了解如何社会方面可能参与神经性厌食症（AN）的食物限制行为。为此，AN患者（限制型）和健康参与者将在功能性磁共振成像期间进行两种实验范式。在第一个范式中，将检查对预期食物和非食物奖励的神经反应，并将个人奖励（自己获胜的经验）与替代奖励（他人获胜的经验）进行对比。我假设，健康受试者的奖励系统中的反应在对个人奖励的反应中会比对另一个人的反应更强烈，并且取决于归因于奖励的主观价值（在功能磁共振成像扫描后评定）。然而，在AN患者中，我希望找到不同的反应：我假设AN患者的神经反应和价值评级与健康对照组在与食物无关的（金钱）奖励方面没有差异，但由于基于不愿增加体重和避免食物等目标的负面评价，在预期个人食物奖励期间会减少。此外，我预计AN患者的认知控制网络结构在对食物相关刺激的反应中更加活跃。然而，当食物奖励被间接处理时，我假设AN患者的奖励反应不会减少，因为这些反应与（个人）体重增加无关，也与自己的认知目标无关。相反，与健康参与者相比，它们可能会增加，表明AN中的社会比较过程和来自他人饮食的替代性快乐。在第二种范式中，将研究与社交饮食情况相关的神经激活，将参与者想象饮食的情况与只有其他人在吃的情况进行对比。我认为，在别人面前吃饭的想象会使AN患者感到羞耻，这是由于社会比较过程，因为它揭示了缺乏自我控制和偏离个人目标和理想。因此，我假设AN患者会对涉及个人饮食想象的社交情境表达更强烈的羞耻感（在扫描后评级中），并且与健康对照组相比，AN相关的大脑网络会表现出更强的激活。相比之下，当他们想象自己处于一个只看到别人吃东西的社交场合时，AN患者甚至可能会表现出自豪感和替代性快乐（与中脑边缘奖励系统的激活增加有关）。有了计划的项目，我希望能提供有关AN限制性饮食行为机制的重要信息，这可能有助于开发更有效的治疗策略，以减少复发或预防处于危险中的个体的疾病发作。

The aim of the planned project is to increase the understanding how social aspects might be involved in food-restrictive behavior in anorexia nervosa (AN). To this end, AN patients (restrictive type) and healthy participants will perform two experimental paradigms during functional magnetic resonance imaging. In the first paradigm, neural responses to anticipated food and non-food rewards will be examined and personal rewards (experience of own win) will be contrasted to vicarious rewards (experience of others’ wins). I hypothesize that reactions in the reward system of healthy subjects will be stronger in response to personal rewards compared to those for another person and will depend on the subjective value attributed to the reward (rated after fMRI scanning). However, in patients with AN I expect to find different responses: I assume that neural responses and value ratings of AN patients will not differ from healthy controls regarding food-unrelated (monetary) rewards, but will be reduced during the anticipation of personal food rewards due to negative appraisal which is based on the reluctance to gain weight and goals such as food avoidance. Furthermore, I expect structures of the cognitive control network to be more active in AN patients in response to food-related stimuli. However, when food rewards are vicariously processed I assume that reward responses will not be diminished in AN patients, since these are not associated with (personal) weight gain or in conflict with own cognitive goals. Instead, they might be increased compared to healthy participants, indicating social comparison processes in AN and vicarious pleasure from others' eating. I the second paradigm, neural activations related to social eating situations will be investigated, contrasting situations in which participants imagine eating to situations in which only other persons are eating. I assume that imagination of eating in the presence of others elicits shame in AN patients due to social comparison processes, because it reveals a lack of self-control and deviation from personal goals and ideals. Thus, I hypothesize that patients with AN will express stronger feelings of shame (in post-scan ratings) for social situations which involve the imagination of personal eating and will show stronger activation of shame-associated brain networks compared to healthy controls. In contrast, when they imagine being in social situations where they only observe someone else eating, patients with AN might even react with pride and vicarious pleasure (associated with increased activations in the mesolimbic reward system).With the planned project, I expect to provide important information about mechanisms that underlie restrictive eating behavior in AN what might help to develop more effective treatment strategies to reduce relapse or prevent the onset of the disorder in individuals at risk.