Kerwin Lauren, Hovav Sarit, Hellemann Gerhard, Feusner Jamie D
UCLA Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, USA.
Creighton University/University of Nebraska Medical Center, Department of Psychiatry, USA.
J Psychiatr Res. 2014 Oct;57:41-50. doi: 10.1016/j.jpsychires.2014.06.003. Epub 2014 Jun 14.
Body dysmorphic disorder (BDD) is characterized by distressing and often debilitating preoccupations with misperceived defects in appearance. Research suggests that aberrant visual processing may contribute to these misperceptions. This study used two tasks to probe global and local visual processing as well as set-shifting in individuals with BDD. Eighteen unmedicated individuals with BDD and 17 non-clinical controls completed two global-local tasks. The embedded figures task requires participants to determine which of three complex figures contains a simpler figure embedded within it. The Navon task utilizes incongruent stimuli comprised of a large letter (global level) made up of smaller letters (local level). The outcome measures were response time and accuracy rate. On the embedded figures task, BDD individuals were slower and less accurate than controls. On the Navon task, BDD individuals processed both global and local stimuli slower and less accurately than controls, and there was a further decrement in performance when shifting attention between the different levels of stimuli. Worse insight correlated with poorer performance on both tasks. Taken together, these results suggest abnormal global and local processing for non-appearance related stimuli among BDD individuals, in addition to evidence of poor set-shifting abilities. Moreover, these abnormalities appear to relate to the important clinical variable of poor insight. Further research is needed to explore these abnormalities and elucidate their possible role in the development and/or persistence of BDD symptoms.
身体变形障碍（BDD）的特征是对感知到的外貌缺陷感到痛苦，且这种困扰常常使人衰弱。研究表明，异常的视觉处理可能导致这些错误认知。本研究使用两项任务来探究BDD个体的整体和局部视觉处理以及定势转换能力。18名未服药的BDD个体和17名非临床对照者完成了两项整体-局部任务。嵌入式图形任务要求参与者确定三个复杂图形中哪一个包含嵌入其中的较简单图形。纳冯任务使用由较小字母（局部水平）组成的大字母（整体水平）构成的不一致刺激。结果测量指标为反应时间和准确率。在嵌入式图形任务中，BDD个体比对照组反应更慢且准确率更低。在纳冯任务中，BDD个体处理整体和局部刺激的速度比对照组更慢且准确率更低，并且在不同水平的刺激之间转移注意力时，表现会进一步下降。洞察力较差与两项任务的较差表现相关。综上所述，这些结果表明BDD个体在处理与外貌无关的刺激时存在整体和局部处理异常，此外还有定势转换能力差的证据。此外，这些异常似乎与洞察力差这一重要临床变量有关。需要进一步研究来探索这些异常，并阐明它们在BDD症状的发展和/或持续存在中可能扮演的角色。
