Medial cortex activity, self-reflection and depression
Medial cortex activity, self-reflection and depression
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DOI：
10.1093/scan/nsp022
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发表时间：
2009-12-01
影响因子：
4.2
通讯作者：
Levin, Yael
中科院分区：
文献类型：
--
作者：
Johnson, Marcia K.;Nolen-Hoeksema, Susan;Levin, Yael
使用功能性磁共振成像，我们研究了抑郁[当前重度抑郁发作（MDE）]和健康对照参与者与自我反思相关的神经活动，重点关注先前显示与自我反思相关的内侧皮层区域。MDE和健康对照组都表现出更大的活动前内侧皮层（内侧额回，前扣带回）时，提示认为希望和愿望相比，责任和义务，更大的活动后内侧皮层（楔前叶，后扣带回）时，提示认为责任和义务（实验1）。然而，MDE组表现出较少的活动比对照组在同一地区的内侧额叶皮层时，自我参照的线索更模糊的效价（实验2），和较少的失活在非自我参照条件下，在这两个实验。此外，在非自我参照条件下，反刍的个体差异与前内侧皮层和后内侧皮层的活动呈正相关。这些结果提供了会聚的证据，前内侧皮层和后内侧皮层的分离取决于自我相关思想的焦点。他们还提供了与行为研究结果一致的神经证据，即抑郁症与对模糊线索的积极评价思想的破坏有关，并且在适当的时候难以脱离自我反思。
Using functional magnetic resonance imaging, we investigated neural activity associated with self-reflection in depressed [current major depressive episode (MDE)] and healthy control participants, focusing on medial cortex areas previously shown to be associated with self-reflection. Both the MDE and healthy control groups showed greater activity in anterior medial cortex (medial frontal gyrus, anterior cingulate gyrus) when cued to think about hopes and aspirations compared with duties and obligations, and greater activity in posterior medial cortex (precuneus, posterior cingulate) when cued to think about duties and obligations (Experiment 1). However, the MDE group showed less activity than controls in the same area of medial frontal cortex when self-referential cues were more ambiguous with respect to valence (Experiment 2), and less deactivation in a non-self-referential condition in both experiments. Furthermore, individual differences in rumination were positively correlated with activity in both anterior and posterior medial cortex during non-self-referential conditions. These results provide converging evidence for a dissociation of anterior and posterior medial cortex depending on the focus of self-relevant thought. They also provide neural evidence consistent with behavioral findings that depression is associated with disruption of positively valenced thoughts in response to ambiguous cues, and difficulty disengaging from self-reflection when it is appropriate to do so.