Social aspects of restrictive eating behavior in anorexia nervosa

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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.