Schneider F, Bermpohl F, Heinzel A, Rotte M, Walter M, Tempelmann C, Wiebking C, Dobrowolny H, Heinze H J, Northoff G
Department of Psychiatry, University of Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany.
Neuroscience. 2008 Nov 11;157(1):120-31. doi: 10.1016/j.neuroscience.2008.08.014. Epub 2008 Aug 19.
The resting brain shows high neural activity in various regions, the default-mode network, chief among them the cortical midline structures (CMS). The psychological correlate of high resting state neural activity in CMS remains however unclear though speculatively it has been associated with processing of internally-oriented self-relatedness. We used functional MRI to examine internally-oriented self-relatedness during the resting state period. This was indirectly done by letting subjects perceive emotional pictures followed by a fixation cross; the very same pictures were then rated subjectively according to their degree of self-relatedness in a postscanning session. This allowed us to correlate the picture ratings of self-relatedness with signal changes in the subsequent resting state period, i.e. fixation period. The emotional pictures' degree of self-relatedness parametrically modulated subsequent resting state signal changes in various CMS, including ventro- and dorsomedial prefrontal cortex and posterior cingulate cortex. This modulation could be distinguished from effects of emotion dimensions (e.g. valence, intensity) and evoked effects of self-relatedness during the stimulus period itself the latter being observed rather in subcortical regions, e.g. amygdala, ventral striatum, and tectum. In sum, our findings suggest that resting state neural activity in CMS is parametrically and specifically modulated by the preceding stimulus's degree of self-relatedness. This lends further support to the presumed involvement of these regions in processing internally-oriented self-relatedness as distinguished from externally-oriented self-relatedness.
静息状态下的大脑在各个区域呈现出较高的神经活动，即默认模式网络，其中主要是皮质中线结构（CMS）。然而，CMS中静息状态下高神经活动的心理关联仍不明确，尽管据推测它与内在导向的自我关联性处理有关。我们使用功能磁共振成像来检查静息状态期间的内在导向自我关联性。这是通过让受试者先观看情绪图片，随后是注视十字来间接完成的；然后在扫描后的阶段，让受试者根据图片与自我的关联程度对相同的图片进行主观评分。这使我们能够将自我关联性的图片评分与随后静息状态期间（即注视期）的信号变化相关联。情绪图片的自我关联程度以参数方式调节了包括腹内侧和背内侧前额叶皮质以及后扣带回皮质在内的各种CMS中随后的静息状态信号变化。这种调节可以与情绪维度（如效价、强度）的影响以及刺激期本身自我关联性的诱发效应区分开来，后者更多地在皮质下区域观察到，如杏仁核、腹侧纹状体和顶盖。总之，我们的研究结果表明，CMS中的静息状态神经活动受到先前刺激的自我关联程度的参数性和特异性调节。这进一步支持了这些区域参与内在导向自我关联性处理（与外在导向自我关联性相区别）的推测。
