Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; BC Mental Health and Addictions Research Institute, Provincial Health Services Authority, Vancouver, BC, Canada.
Multimodal Imaging Group - Research Imaging Centre and Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, Canada; Department of Psychiatry, University of Toronto, Toronto, Canada.
Psychiatry Res Neuroimaging. 2017 May 30;263:32-43. doi: 10.1016/j.pscychresns.2017.03.005. Epub 2017 Mar 9.
Delusions of reference in schizophrenia are thought to result from misattributions of self-relevance to neutral events. Activation of regions within the cortical midline structures (CMS; e.g., medial prefrontal cortex, cingulate cortex, and precuneus) have been previously associated with self-referential processing in schizophrenia patients; however, the specificity of this pattern to individuals with current delusions of reference has yet to be determined. In the present study, we identified functional brain networks that underlie self-referential processing using task-based multivariate functional connectivity. Healthy control subjects (n=15) and schizophrenia patients with (n=14) and without (n=13) current delusions of reference were shown ambiguous statements while undergoing functional magnetic resonance imaging, and evaluated whether these statements were thought to be specifically about them. Our results revealed two functionally distinct CMS networks that differed between patients and controls during self-referential processing: a posterior CMS network, which showed muted deactivity in non-delusional patients; and an anterior CMS network, in which delusional patients demonstrated hyperactivity. Furthermore, activity within the anterior CMS network across the three groups showed a linear pattern of increasing activity associated with greater intensity of delusions of reference, suggesting that hyperactivity in this network may underlie delusions of reference.
精神分裂症的关系妄想被认为是由于将自我相关性错误地归因于中性事件而产生的。皮质中线结构（CMS；例如，内侧前额叶皮层、扣带回皮层和楔前叶）内的区域的激活与精神分裂症患者的自我参照处理有关；然而，这种模式对当前有妄想关系的个体的特异性尚未确定。在本研究中，我们使用基于任务的多变量功能连接来确定自我参照处理的功能脑网络。我们让健康对照组（n=15）和有（n=14）和没有（n=13）当前妄想关系的精神分裂症患者观看模糊的陈述，同时进行功能磁共振成像，并评估这些陈述是否被认为是专门针对他们的。我们的结果显示，在自我参照处理过程中，患者和对照组之间存在两个功能上明显不同的 CMS 网络：一个是后 CMS 网络，在非妄想患者中表现出活动减弱；另一个是前 CMS 网络，在妄想患者中表现出过度活跃。此外，三个组的前 CMS 网络内的活动表现出与妄想关系强度增加相关的线性活动模式，这表明该网络的过度活跃可能是妄想关系的基础。
