Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown, MA 02129, USA.
Biol Psychiatry. 2011 Mar 1;69(5):415-23. doi: 10.1016/j.biopsych.2010.10.003. Epub 2010 Dec 8.
Deficits in social cognition, including impairments in self-awareness, contribute to the overall functional disability associated with schizophrenia. Studies in healthy subjects have shown that social cognitive functions, including self-reflection, rely on the medial prefrontal cortex (mPFC) and posterior cingulate gyrus, and these regions exhibit highly correlated activity during "resting" states. In this study, we tested the hypothesis that patients with schizophrenia show dysfunction of this network during self-reflection and that this abnormal activity is associated with changes in the strength of resting-state correlations between these regions.
Activation during self-reflection and control tasks was measured with functional magnetic resonance imaging in 19 patients with schizophrenia and 20 demographically matched control subjects. In addition, the resting-state functional connectivity of midline cortical areas showing abnormal self-reflection-related activation in schizophrenia was measured.
Compared with control subjects, the schizophrenia patients demonstrated lower activation of the right ventral mPFC and greater activation of the mid/posterior cingulate gyri bilaterally during self-reflection, relative to a control task. A similar pattern was seen during overall social reflection. In addition, functional connectivity between the portion of the left mid/posterior cingulate gyrus showing abnormally elevated activity during self-reflection in schizophrenia, and the dorsal anterior cingulate gyrus was lower in the schizophrenia patients compared with control subjects.
Schizophrenia is associated with an anterior-to-posterior shift in introspection-related activation, as well as changes in functional connectivity, of the midline cortex. These findings provide support for the hypothesis that aberrant midline cortical function contributes to social cognitive impairment in schizophrenia.
社会认知缺陷，包括自我意识障碍，是与精神分裂症相关的整体功能障碍的原因。在健康受试者中的研究表明，社会认知功能，包括自我反省，依赖于内侧前额叶皮层（mPFC）和后扣带回，这些区域在“休息”状态下表现出高度相关的活动。在这项研究中，我们假设精神分裂症患者在自我反省时表现出该网络的功能障碍，并且这种异常活动与这些区域之间静息状态相关性的强度变化有关。
通过功能磁共振成像测量 19 名精神分裂症患者和 20 名年龄匹配的对照者在自我反省和对照任务期间的激活情况。此外，还测量了在精神分裂症中表现出异常自我反省相关激活的中线皮质区域的静息状态功能连接。
与对照组相比，精神分裂症患者在自我反省时右腹侧 mPFC 的激活较低，双侧中/后扣带回的激活较高，而在对照任务时则相反。在整体社会反省中也观察到类似的模式。此外，在精神分裂症中自我反省时左中/后扣带回的一部分显示出异常升高的活动，与背侧前扣带回之间的功能连接在精神分裂症患者中低于对照组。
精神分裂症与自我反省相关的激活的从前向后转移以及中线皮质的功能连接变化有关。这些发现为异常中线皮质功能导致精神分裂症社会认知障碍的假设提供了支持。
