Dissociating Bottom-Up and Top-Down Mechanisms in the Cortico-Limbic System during Emotion Processing
Dissociating Bottom-Up and Top-Down Mechanisms in the Cortico-Limbic System during Emotion Processing
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DOI：
10.1093/cercor/bhu185
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发表时间：
2016-01-01
期刊：
影响因子：
3.7
通讯作者：
Fakra, Eric
中科院分区：
文献类型：
--
作者：
Comte, Magali;Schoen, Daniele;Fakra, Eric
皮质-边缘系统在情绪反应和由此产生的适应行为中起着至关重要的作用。在这个回路中，互补区域被认为参与了对情感状态的评估或调节。然而，这些自下而上和自上而下的机制在情绪加工过程中各自的贡献还有待阐明。我们使用一种新的功能磁共振成像(FMRI)范式，改变3个参数：情绪配价、情绪一致性和注意力分配，以区分杏仁核、前扣带回(ACC)和背外侧前额叶(DLPFC)之间活动和连接的功能差异。与正面刺激相比，自下而上评估负面刺激导致杏仁核反应更强，杏仁核与背侧ACC和DLPFC之间的功能相互作用更强。情绪冲突的自上而下的解决与ACC内活动的增加以及该结构与杏仁核和DLPFC之间更高的功能连接有关。最后，自上而下注意控制的增加导致了DLPFC的更大参与，同时DLPFC和背侧ACC之间的连接也增加了。这项新颖的任务为探索情绪背后的自下而上和自上而下的过程提供了一个有效的工具，可能对研究精神障碍的神经功能基础特别有帮助。
The cortico-limbic system is critically involved in emotional responses and resulting adaptive behaviors. Within this circuit, complementary regions are believed to be involved in either the appraisal or the regulation of affective state. However, the respective contribution of these bottom-up and top-down mechanisms during emotion processing remains to be clarified. We used a new functional magnetic resonance imaging (fMRI) paradigm varying 3 parameters: emotional valence, emotional congruency, and allocation of attention, to distinguish the functional variation in activity and connectivity between amygdala, anterior cingulate cortex (ACC), and dorsolateral prefrontal cortex (DLPFC). Bottom-up appraisal of negative compared with positive stimuli led to a greater amygdala response and stronger functional interaction between amygdala and both dorsal ACC and DLPFC. Top-down resolution of emotional conflict was associated with increased activity within ACC and higher functional connectivity between this structure, and both the amygdala and DLPFC. Finally, increased top-down attentional control caused greater engagement of the DLPFC, accompanied by increased connectivity between DLPFC and dorsal ACC. This novel task provides an efficient tool for exploring bottom-up and top-down processes underlying emotion and may be particularly helpful for investigating the neurofunctional underpinnings of psychiatric disorders.