静息态fMRI观察短期正念减压训练对大脑功能网络小世界属性的影响

Resting-state fMRI observation on impact of short-term training of mindfulness-based stress reduction on small-world network characteristics

目的采用基于图论的复杂网络分析观察短期正念减压训练对大脑功能网络小世界属性的影响。方法采用自身前后对照设计,纳入16名健康志愿者,对其进行8周正念减压训练,采集训练前后静息态fMRI数据,并对其进行正念五因素量表与积极情绪和消极情绪量表评定。计算复杂网络小世界属性参数,并比较正念减压训练前后的差异。结果 8周正念减压训练后,稀疏度阈值为1%~16%时,受试者全脑局部效率(E_(loc))、标准化聚类系数(γ)、小世界值(σ)均下降(P均<0.05)。稀疏度阈值为20%时,双侧扣带回中部、双侧杏仁体、右侧壳核、左侧丘脑的节点全局效率E_(i_glob)升高,左侧背外侧额上回、右侧额上回眶部、双侧缘上回E_(i_glob)降低(P均<0.05);左侧海马、左侧尾状核、右侧丘脑的节点局部效率E_(i_loc)升高,右侧扣带回后部、顶下缘角回E_(i_loc)降低(P均<0.05)。E_(i_glob)与正念能力呈负相关的脑区包括右侧额上回眶部、右侧缘上回,呈正相关的脑区有右侧杏仁体、右侧壳核;双侧杏仁体的E_(i_glob)与消极情绪得分呈正相关,左侧丘脑的E_(i_glob)与积极情绪得分呈正相关,右侧顶下缘角回的E_(i_loc)与观察因子、积极情绪得分呈负相关。结论短期正念减压训练能引起大脑功能网络小世界属性改变,主要涉及皮质—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。

Objective To explore the impact of mindfulness-based stress reduction（MBSR）training on small-world network characteristics using complex network analysis based on graph theory.Methods Using self-controlled design,16 healthy volunteers were recruited and trained with 8 weeks MBSR.Resting-state fMRI data were collected before and after training.Mindfulness ability and emotional state were evaluated using five facet mindfulness questionnaire（FFMQ）and positive and negative affect schedule（PANAS）.The small-world network parameters were calculated and compared to detect the differences between pre-and post-MBSR assessment.Results After 8 weeks MBSR training,in sparsity threshold of 1%—16%,reduction of local efficiency（Eloc）,normalized clustering coefficiency（γ）and small-worldness（σ）were detected in whole brain analysis（all P〈0.05）.In sparsity threshold of 20%,global efficient（Eiglob）increased in bilateral dorsal cingulate cortex and bilateral amygdala,right putamen,left thalamus,while decreased in left dorsolateral part of superior frontal gyrus and right orbital part of superior frontal gyrus,as well as bilateral supramarginal gyrus（all P〈0.05）.Local efficiency（Eiloc）increased in the left hippocampus,left caudate and right thalamus,but decreased in right posterior cingulate cortex and right inferior parietal cortex supramarginal angular gyri（all P〈0.05）.Eigloband mindfulness skill were negatively correlated in right orbital part of superior frontal gyrus and right supramarginal gyrus,while positively correlated in the right amygdala and right putamen.Eiglobwas positively correlated with negative effect in bilateral amygdala,and positively correlated with positive effect in left thalamus.Eilocof the right inferior parietal cortex supramarginal angular gyri was negatively correlated with observing score and positive affect.Conclusion The small-world topology of the complex functional network was affected by short-term MBSR training.The basal ganglia-thalamocortical circuits were mainly involved.The certain nodal property could reflect mindfulness skill and affective state.