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

项目摘要 患有身体畸形恐惧症（BDD）的人错误地认为他们外表的特定方面是 有明显的瑕疵或缺陷，尽管这些在别人看来是不明显的或微不足道的。与 他们通常有不良的洞察力或妄想的信念，强迫症， 思想和强迫行为焦虑和抑郁这些导致在以下方面的重大困难： 功能障碍、抑郁、自杀企图（25%）和精神病住院（50%）。尽管如此，相对 已经进行了很少的神经生物学研究和很少的治疗研究。这凸显了一个关键的 需要进行研究，以确定新的干预目标， 病理生理机制神经心理学、行为学和神经生物学研究 其他人已经发现了可能导致感知扭曲的机制，包括突出的 视觉处理系统的异常这些都有助于减少全球/整体的模式， 处理和增强的局部/详细处理，归因于“自下而上”和“自上而下”的干扰， perception.使用心理物理学实验和新颖的视觉调制技术，我们已经探讨了 大脑的视觉系统负责全局和局部处理，并发现了早期证据，表明它们可能是 可在BDD中修改。这些技术包括“自上而下”的注意力调节和“自下而上”的知觉调节。 调制策略异常的眼睛注视和情绪激动时，观看面孔可能进一步有助于 不正常的知觉这些大脑和行为异常是否与异常 感知有待理解。因此，本研究将确定a）如果神经系统异常， 当观察一个人的外表时，BDD中的激活和连接与异常直接相关 B）如果这些视觉调节引起神经激活和连接的变化， 策略与感知功能的变化有关，因此代表了潜在的生物标志物。我们还将 确定注意力系统，眼睛凝视行为和情绪唤起如何与大脑功能相互作用， 视觉系统，以及全局和局部感知功能。我们将招募80名BDD参与者，40名 亚临床BDD患者和40名健康对照者，他们将接受功能性磁共振成像， 查看自己和其他人的脸部照片。我们将获得全局和局部视觉处理的测量结果， 观察他们的脸时的情绪唤起，以及使用眼动跟踪的眼睛注视行为。了解 全局/局部感知的延展性，以及这些变化的神经机制，我们将确定是否 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/连接，以及它们之间的关系。结果将提供 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。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.