Ritter Viktoria, Kaufmann Jürgen M, Krahmer Franziska, Wiese Holger, Stangier Ulrich, Schweinberger Stefan R
Department of Clinical Psychology and Psychotherapy, Institute of Psychology, Goethe University, Frankfurt, Germany.
Department of General Psychology and Cognitive Neuroscience, Institute of Psychology, Friedrich Schiller University, Jena, Germany.
Front Psychiatry. 2020 Apr 24;11:302. doi: 10.3389/fpsyt.2020.00302. eCollection 2020.
Body 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.
We 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.
In 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.
The 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.
躯体变形障碍（BDD）的特征是过度关注自身外貌中一个或多个被察觉到的缺陷。先前的研究为BDD中构型和整体加工缺陷提供了证据。初步证据表明在视觉加工的早期阶段存在异常。本研究首次使用脑电图（EEG）来检验BDD患者对自身面部的早期神经认知感知。我们研究了面部倒置效应，即与正立面部相比，倒置（上下颠倒）的面部加工明显较差。这种效应反映了构型和整体加工的中断，进而导致面部特征加工占优势。
我们记录了16名BDD患者和16名健康对照者（均未服药）的面部敏感事件相关电位（ERP）。参与者观看自己面部和一张不熟悉他人面部的正立和倒置（上下颠倒）图像，每种图像有两种面部表情（中性与微笑）。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波幅。
在早期的P100中，两组均未发现面部倒置效应。在N170中，两组均表现出常见的面部倒置效应，倒置面部的N170波幅明显大于正立面部。在P200中，两组对他人（相对于自己）面部表现出更大的倒置效应，他人正立面部的P200波幅大于倒置面部。在N250中，面部加工方面未发现显著的组间差异。在LPC中，两组对他人（相对于自己）面部表现出更大的倒置效应，他人倒置面部的LPC波幅大于正立面部。两组的这些总体模式似乎具有可比性。与对照组相比，BDD患者在这些成分中均未观察到对自己（相对于他人）面部的倒置效应较小。
研究结果表明，在我们观察的BDD患者样本中，没有证据表明早期面部加工的各个水平存在异常。进一步的研究应调查BDD症状学背后的神经基础。
