Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States.
Department of Psychology, Drexel University, Philadelphia, PA, United States.
Psychiatry Res Neuroimaging. 2017 Jul 30;265:87-97. doi: 10.1016/j.pscychresns.2016.08.006. Epub 2016 Aug 19.
Obsessive-compulsive disorder (OCD) is characterized by excessive absorption with internally-generated distressing thoughts and urges, with difficulty incorporating external information running counter to their fears and concerns. In the present study, we experimentally probed this core feature of OCD through the use of a novel attention switching task that investigates transitions between internally focused (IF) and externally focused (EF) attentional states. Eighteen OCD patients and 18 controls imagined positive and negative personal event scenarios (IF state) or performed a color-word Stroop task (EF state). The IF/EF states were followed by a target detection (TD) task requiring responses to external stimuli. Compared to controls, OCD patients made significantly more errors and showed reduced activation of superior and inferior occipital cortex, thalamus, and putamen during TD following negative IF, with the inferior occipital hypoactivation being significantly greater for TD following negative IF compared to TD following the other conditions. Patients showed stronger functional connectivity between the inferior occipital region and dorsomedial prefrontal cortex. These findings point to an OCD-related impairment in the visual processing of external stimuli specifically when they follow a period of negative internal focus, and suggest that future treatments may wish to target the transition between attentional states.
强迫症（OCD）的特征是过度关注内部产生的痛苦思想和冲动，难以将与恐惧和担忧相悖的外部信息纳入其中。在本研究中，我们通过使用一种新颖的注意转换任务来实验性地探究 OCD 的这一核心特征，该任务调查了内部关注（IF）和外部关注（EF）注意状态之间的转变。18 名 OCD 患者和 18 名对照组被试想象积极和消极的个人事件场景（IF 状态）或执行颜色-词斯特鲁普任务（EF 状态）。IF/EF 状态之后是目标检测（TD）任务，要求对外部刺激做出反应。与对照组相比，OCD 患者在 TD 后出现更多错误，并且在 IF 后出现消极的 TD 时，上顶叶和下顶叶、丘脑和壳核的激活明显减少，IF 后出现消极 TD 时的下枕叶激活明显大于其他条件。患者在 IF 后出现消极 TD 时，下枕叶与背内侧前额叶皮质之间的功能连接更强。这些发现表明，OCD 患者在处理外部刺激时存在视觉处理方面的损伤，尤其是在经历一段消极的内部关注之后，这表明未来的治疗可能需要针对注意力状态之间的转换。
