Neural mechanisms of perceptual abnormalities and their malleability in body dysmorphic disorder

项目总结 躯体变形障碍(BDD)患者错误地认为他们外表的特定方面是 明显的缺陷或缺陷，尽管这些在其他人看来是不明显的或微不足道的。使用 毁容和丑陋的定罪，他们通常缺乏洞察力或妄想信念，强迫症 思想和强迫行为，焦虑和抑郁。这些都造成了严重的困难 功能障碍、抑郁、自杀未遂(25%)和精神科住院(50%)。尽管如此，相对 对神经生物学的研究很少，治疗研究也很少。这突显了一个关键的 需要进行研究，以确定新的干预目标，其基础是对 病理生理机制。我们小组进行的神经心理学、行为学和神经生物学研究 其他人发现了可能导致知觉扭曲的机制，包括突出的 视觉处理系统中的异常。这些都促成了一种全球/整体减少的模式 处理和增强的本地/详细处理，归因于#年的“自下而上”和“自上而下”的干扰 感知力。利用心理物理实验和新的视觉调制技术，我们探索了 大脑的视觉系统负责全局和局部处理，并发现早期证据表明，它们可能是 可在BDD中修改。这些技术包括“自上而下”的注意调制和“自下而上”的知觉 调制策略。看脸时不正常的眼睛凝视和情绪唤醒可能会进一步导致 不正常的感觉。这些大脑和行为异常是否与异常直接相关 人们的看法还有待理解。因此，这项研究将确定a)神经异常 当观看一个人的外表时，BDD中的激活和连接直接与异常相关 知觉功能；以及b)如果这些视觉调制引起的神经激活和连接的变化 策略与知觉功能的变化有关，因此代表了潜在的生物标记物。我们还将 确定注意系统、眼睛凝视行为和情绪唤醒如何与大脑功能相互作用 视觉系统，并具有全球和局部知觉功能。我们将招募80名BDD参与者，40名 和40名健康对照，他们将接受功能性磁共振成像，同时 查看自己和其他人的面孔照片。我们将获得全球和局部视觉处理的测量结果， 看着他们的脸时的情绪唤醒，以及使用眼球跟踪的眼睛凝视行为。要了解 全局/局部感知的延展性，以及这些变化的神经机制，我们将确定 使用自上而下和自下而上策略的重复视觉调制导致知觉的改变 功能和大脑活动/连通性，以及它们之间的关系。结果将提供一个 核心症状下异常视觉信息加工的综合机制模型 对外表的误解的领域。这将为下一步的翻译方法奠定基础。

PROJECT SUMMARY Individuals with body dysmorphic disorder (BDD) misperceive specific aspects of their appearance to be conspicuously flawed or defective, despite these being unnoticeable or appearing miniscule to others. With convictions of disfigurement and ugliness, they typically have poor insight or delusional beliefs, obsessive thoughts and compulsive behaviors, anxiety, and depression. These result in significant difficulties in functioning, depression, suicide attempts (25%), and psychiatric hospitalization (50%). Despite this, relatively few studies of the neurobiology, and few treatment studies, have been conducted. This underscores a critical need for research to identify novel targets for intervention based on a comprehensive understanding of the pathophysiological mechanisms. Neuropsychological, behavioral, and neurobiological research by our group and others have uncovered mechanisms that may contribute to perceptual distortions, including prominent abnormalities in visual processing systems. These have contributed to a model of diminished global/holistic processing and enhanced local/detailed processing, attributed to “bottom-up” and “top-down” disturbances in perception. Using psychophysical experiments and novel visual modulation techniques, we have probed the brain’s visual systems responsible for global and local processing and found early evidence that they may be modifiable in BDD. These techniques include a “top-down” attentional modulation and a “bottom-up” perceptual modulation strategy. Abnormal eye gaze and emotional arousal when viewing faces may further contribute to abnormal perception. Whether these brain and behavior abnormalities are directly linked to abnormal perception remains to be understood. Accordingly, this study will determine a) if abnormalities in neural activation and connectivity in BDD when viewing one’s appearance are directly associated with abnormalities in perceptual functioning; and b) if changes in neural activation and connectivity from these visual modulation strategies are linked to changes in perceptual functioning, thus representing potential biomarkers. We will also determine how attentional systems, eye gaze behaviors and emotional arousal interact with brain functioning in visual systems, and with global and local perceptual functioning. We will enroll 80 participants with BDD, 40 with subclinical BDD, and 40 healthy controls who will undergo functional magnetic resonance imaging while viewing photographs of their, and others’, faces. We will obtain measures of global and local visual processing, emotional arousal while viewing their face, and eye gaze behaviors using eye tracking. To understand the malleability of global/local perception, and the neural mechanisms of these changes, we will determine whether repeated visual modulation using top-down and bottom-up strategies results in alterations of perceptual functioning and brain activity/connectivity, and relationships between them. Results will provide a comprehensive mechanistic model of abnormal visual information processing underlying the core symptom domain of misperceptions of appearance. This will lay the groundwork for next-step translational approaches.