DataSheet_1_Neural Correlates of Own- and Other-Face Perception in Body Dysmorphic Disorder.docx

BackgroundBody dysmorphic disorder (BDD) is characterized by an excessive preoccupation with one or more perceived flaws in one’s own appearance. Previous studies provided evidence for deficits in configural and holistic processing in BDD. Preliminary evidence suggests abnormalities at an early stage of visual processing. The present study is the first examining early neurocognitive perception of the own face in BDD by using electroencephalography (EEG). We investigated the face inversion effect, in which inverted (upside-down) faces are disproportionately poorly processed compared to upright faces. This effect reflects a disruption of configural and holistic processing, and in consequence a preponderance of featural face processing.MethodsWe recorded face-sensitive event-related potentials (ERPs) in 16 BDD patients and 16 healthy controls, all unmedicated. Participants viewed upright and inverted (upside-down) images of their own face and an unfamiliar other face, each in two facial emotional expressions (neutral vs. smiling). We calculated the early ERP components P100, N170, P200, N250, and the late positive component (LPC), and compared amplitudes among both groups.ResultsIn the early P100, no face inversion effects were found in both groups. In the N170, both groups exhibited the common face inversion effects, with significantly larger N170 amplitudes for inverted than upright faces. In the P200, both groups exhibited larger inversion effects to other (relative to own) faces, with larger P200 amplitudes for other upright than inverted faces. In the N250, no significant group differences were found in face processing. In the LPC, both groups exhibited larger inversion effects to other (relative to own) faces, with larger LPC amplitudes for other inverted than upright faces. These overall patterns appeared to be comparable for both groups. Smaller inversion effects to own (relative to other) faces were observed in none of these components in BDD, relative to controls.ConclusionsThe findings suggest no evidence for abnormalities at all levels of early face processing in our observed sample of BDD patients. Further research should investigate the neural substrates underlying BDD symptomatology.

背景体象障碍（BDD）以对自身外貌中一个或多个感知到的缺陷过度关注为特征。先前的研究为BDD中配置性和整体处理能力的缺陷提供了证据。初步证据表明，在视觉处理的早期阶段存在异常。本研究所为首次通过使用脑电图（EEG）来探讨BDD患者自身面部早期神经认知感知的研究。我们研究了面部反转效应，即与直立面部相比，反转（颠倒）面部被不成比例地较差地处理。此效应反映了配置性和整体处理的破坏，从而导致了特征性面部处理的突出。方法我们记录了16名BDD患者和16名健康对照者的面部敏感事件相关电位（ERP），所有参与者均未服用药物。参与者观看自身面部和陌生他面部直立和反转（颠倒）的图像，每种图像均有两种面部情绪表情（中性 vs. 微笑）。我们计算了早期ERP成分P100、N170、P200、N250以及晚期正成分（LPC），并比较了两组之间的振幅。结果在早期P100中，两组均未发现面部反转效应。在N170中，两组均表现出常见的面部反转效应，反转面部比直立面部的N170振幅显著更大。在P200中，两组均表现出对其他（相对于自身）面部的较大反转效应，其他直立面部的P200振幅大于反转面部。在N250中，面部处理方面未发现两组间的显著差异。在LPC中，两组均表现出对其他（相对于自身）面部的较大反转效应，其他反转面部的LPC振幅大于直立面部。这些整体模式在两组中似乎相似。与对照者相比，在BDD中，这些成分中未见较小的自身（相对于其他）面部反转效应。结论研究发现，在我们观察的BDD患者样本中，早期面部处理的各个层次均未发现异常的证据。进一步的研究应调查BDD症状学背后的神经基础。