Neural Mechanisms of Food Choice in Anorexia Nervosa

 描述(申请人提供)：节食，一种试图限制食物摄入量和/或类型的尝试，在美国非常普遍，尤其是在女性中。它有时是有益的，但往往无效或令人沮丧，有时令人苦恼，甚至危险。在节食者中，有1/3成为“病理性节食者”，其中有1/4的人会出现饮食失调。追求低卡路里/低脂肪饮食是一系列饮食失调的标志。核心挑战是理解持续选择低卡路里饮食背后的认知和神经生物学机制，以及这种行为如何跨越饮食限制的范围，从潜在的健康促进转变为潜在的致命。解决这一挑战的一个关键障碍是，在关于健康人选择的神经基础的研究和关于饮食障碍的卡路里限制的研究之间存在着长期的差距。特别是，在理解健康大脑中潜在的选择机制方面取得了实质性的进展。但对进食障碍的研究通常集中在表征大脑对被动观看食物的反应--这些研究并未明确将神经反应与限制进食行为本身联系起来。为了克服这一障碍，拟议的研究计划试图利用人类认知神经科学的最新进展，在整个饮食限制范围内了解食物选择背后的神经生物学机制。我们的具体目标是研究指导积极食物选择的神经机制，这些人的行为范围从健康饮食限制到病理性饮食限制。我们将使用功能磁共振结合食物选择任务来测量与选择行为直接相关的大样本个体的大脑活动，涉及一系列 饮食限制的范围从健康对照到健康节食者，到阈值以下的AN，以及患有完整综合征AN的个人。我们还将使用区分基于习惯的学习系统的实验范式，更广泛地研究决策制定。我们的研究将提供第一批数据，证明食物选择机制如何在持续的不适应饮食限制中发挥作用，包括在亚阈值和完全综合征和我们的中心预测是，随着饮食限制的持久性和严重性的增加，食物选择偏好是通过增强的皮质自我控制机制和增加的背侧纹状体习惯机制来调节的。将认知神经科学和饮食失调联系起来的提议将是阐明病理性饮食限制的神经生物学方面的重大进展。 进食障碍的显著特征，可作为研究其他严重精神疾病的持续性适应不良行为的模型。

 DESCRIPTION (provided by applicant): Dieting, an attempt to restrict the quantity and/or type of food ingested, is impressively common in the US, especially among women. It is sometimes beneficial, but often ineffective or frustrating, occasionally distressing or even dangerous. Among dieters, 1/3 become "pathological dieters" and 1/4 of these individuals develop eating disorders. The pursuit of a low-calorie/low-fat diet is a hallmark of a range of eating disorders. central challenge is to understand the cognitive and neurobiological mechanisms underlying the persistent choice of a low-calorie diet and how this behavior transitions across the spectrum of dietary restriction, from potentially health-promoting to potentially deadly. A critical hurdle in addressing this challenge is a long-standing gap between research on the neural underpinnings of choice in healthy individuals and research on caloric restriction in eating disorders. In particular, there have been substantial advances in understanding the mechanisms underlying choices in the healthy brain. But studies of eating disorders have generally focused on characterizing brain responses to passive viewing of food - these studies have not specifically linked neural responses to the restrictive eating behavior itself. To overcome this hurdle, the proposed research program seeks to leverage recent advances in human cognitive neuroscience to understand the neurobiological mechanisms underlying food choice across a full spectrum of dietary restriction. Our specific aim is to examine the neural mechanisms guiding active food choice in individuals whose behavior ranges from healthy to pathological dietary restriction. We will use fMRI combined with a Food Choice Task to measure brain activity directly related to choice behavior in a large sample of individuals, across a spectrum of dietary restriction ranging from healthy controls to healthy dieters, to subthreshold AN and to individuals with full syndrome AN. We will also examine decision-making more broadly, using an experimental paradigm that distinguishes habit-based learning systems. Our study will provide the first data demonstrating how food choice mechanisms function in persistent maladaptive dietary restriction, including among individuals with sub-threshold and full syndrome AN. Our central prediction is that as dietary restriction increases in persistence and severity, food choic preferences are mediated by enhanced cortical self-control mechanisms, and increased dorsal striatal habit mechanisms. The proposed linking of cognitive neuroscience and eating disorders will be a major advance toward elucidating the neurobiology of pathological dietary restriction - a salient feature of eating disorders, and could serve as a model for the study of persistent maladaptive behavior in other serious mental illness.