元觉知神经反馈训练对情绪调节的脑默认网络机制研究

Meta-awareness is the ability to distinguish between the self and conscious content. Its impairment can lead to decrease of self-awareness, which was considered to be the crucial point of psychopathology. When exposed to the observer's perspective, one could obtain an increase in the level of meta-awareness. Therefore, to clarify the key brain mechanism of the acquisition of meta-awareness could be of great significance to many psychological problems. In our previous studies, mindfulness training in short period could lead to alleviation of negative emotion. Besides, weakened activation of salience network (SN) , which encode the saliency of sensory experiences, was observed. SN could exclusively control default mode network (DMN) which is associated with self-awareness. We hypothesized, as the key element of mindfulness, meta-awareness may impact on the inner- and inter-connectivity of DMN, and finally lead to emotion regulation (ER). Whereas, malfunction of SN was commonly detected in ADHD and disruption of ER has been regarded as the core feature of such disease. To elaborate the bran mechanism of meta-awareness on ER, we would train adults patients of ADHD with high homogeneity in symptoms by using real-time neurofeedback practice. We may mainly specify (1) How the DMN was characterized in instant and persisted state of meta-awareness? (2) Can persisted state of improvement in meta-awareness be achieved by neurofeedback training? Then the features of meta-awareness on ER in electrophysiology and neuroimaging will be explored. Thus we may provide basic data for uncovering the neuromechanism of meta-awareness, and provide a theoretical basis for the clinical use of corresponding intervention method.

元觉知是区分自我与意识内容的能力，因其受损导致的自我觉知下降是精神病理的核心，而暴露于观察者视角可获得元觉知改善；故阐明该过程的关键脑机制对精神心理问题有重要意义。我们的前期研究表明，短期正念训练可引起负性情绪减弱，且负责编码感受信息显著性的突显网络激活减弱；因该网络可排他性控制与自我觉知相关的默认网络，我们推测作为正念核心的元觉知或通过影响默认网络的内外部连接尤其是与突显网络的连接而实现情绪调节。鉴于突显网络失调常见于注意缺陷多动障碍(ADHD)且情绪调节异常已被列为此病的核心特征，为验证该假说本研究拟对症状同质性较高的成人ADHD患者结合实时功能磁共振及脑电技术进行神经反馈训练，明确(1)元觉知的即刻及长期效应对应怎样的脑默认网络变化？(2)能否通过神经反馈训练获得元觉知改善的长期效果？以此揭示元觉知情绪调节的影像学特征；为揭示元觉知的神经机制提供基础数据，并为其临床应用提供理论依据。

正念训练已被广泛用于多种情绪问题的临床干预，但其有效性和机制仍有待阐明。元觉知作为正念的核心可能通过影响默认网络的内外部连接，尤其是与突显网络的连接而实现情绪调节。从脑影像学的角度探讨该过程将有助于揭示元觉知情绪调节的神经机制，为提炼总结有针对性的元觉知练习方法提供参考。本项目围绕元觉知训练范式的建立、情绪调节有效性及脑影像机制进行研究，通过训练前后的比较对相关脑功能指标进行分析，总结完善基于观察者视角的、单一可测量的脑电训练范式，主要研究内容及结果如下：（1）优化和完善情绪调节的元觉知训练范式：在正念训练的基础上，整合多种认知行为疗法的相关内容，设置情绪区分、识别和标定，内感受性感知等版块，以强调观察者视角的练习，形成了情绪元觉知训练课程方案；（2）正念练习对情绪调节的效应及脑网络机制研究：观察到边缘系统脑区局部一致性下降，且突显网络与默认网络功能连接增强，该过程可能参与了对焦虑情绪的调节；静息状态下突显网络的低频振幅下降且内部功能连接增强，相应节点的连通性与正念能力和情绪评估有关；复杂网络指标分析提示，全局效率、局部效率及介数改变的节点主要分布在额叶（包括前额叶）、顶叶、颞叶及联合皮层区域、边缘及旁边缘系统和皮层下功能区，且皮质-基底核环路部分脑区节点效率可反映训练后正念能力及情绪状态；（3）脑功能反馈指标筛选：不同训练范式的组内比较发现，与基线状态相比，在训练后静息状态、文字引导练习状态及练习后复测都表现出前额叶区域偏侧化值增大，可作为元觉知能力反馈训练的候选靶点。本项目的研究结果为情绪调节元觉知干预的脑机制探索提供基础数据，为相应干预方案的临床应用、优化及训练效果客观评价提供了新的思路和参考。通过本项目研究，发表标注该基金项目支持的学术论文8篇，其中SCI论文收录3篇，国内核心期刊论文5篇；译著1部；培养硕士研究生7人，已毕业4人；此外，通过本项目的实施延伸申请新的国家自然科学基金项目2项，本项目负责人主持1项，课题组成员主持1项。