Short-term Effects Of Mindfulness-based Stress Reduction On Complex Network Characteristics

Objective FMRI imaging data was collected from the healthy subjects which meet the criteria and the psychological function was evaluated simultaneously.Complex network analysis based on graph theory was adopted to explore the effects of 8-weeks MBSR on complex network characteristics and further reveal the correlation of topology and mindfulness ability as well as emotional state.Methods Sixteen healthy volunteers were recruited and trained with 8 weeks MBSR.Another sixteen healthy adults were recruited as controls and without training.The two groups were matched for age,gender and years of education and lack of meditation experience.Resting-state f MRI data were collected both in baseline and after 8-weeks MBSR training.Mindfulness ability and emotional state were evaluated by using Five Facet Mindfulness Questionnaire(FFMQ)and Positive and Negative Affect Schedule(PANAS).Based on the MATLAB platform,SPM,Gretna and DPARSF package was used to process the data.Time series of 90 regions using AAL template were calculated.Complex network characteristics were extracted for each subject and correlation matrices were analyzed by using paired t-test between pre-and post-training assessment.Results Whole brain analysis revealed reduction of local efficiency,normalized clustering efficiency and small-worldness after MBSR training in sparsity threshold of1%-16%.In sparsity threshold of 20%,global efficiency was changed in the prefrontal lobe,dorsal cingulate gyrus,amygdala,supramarginal gyrus,putamen and thalamus;compared with the baseline data,local efficiency was changed in left hippocampus,left caudate nucleus,right thalamus,right posterior cingulate gyrus and inferior parietal cortex(supramarginal and angular gyri);The betweeness was changed in prefrontal lobe,dorsal cingulate gyrus,amygdala,and parietal lobe regions.Global efficiency of right orbital part of superior frontal gyrus,supramarginal gyrus was negatively correlated with mindfulness ability.While that of right amygdala,putamen and thalamus were positive.Global efficiency of bilateral amygdala and negative affect were positively correlated,and positively correlated with positive affect in left thalamus.Local efficiency of supramarginal and angular gyri in inferior parietal gyrus was negatively correlated with mindfulness ability and positive affect.Increased Degree Centrality of the right dorsal cingulate gyrus(DCG.R)was observed based on voxel-wise analysis.The functional connectivity between DCG.R and bilateral insula,as well as left precuneus increased significantly.Conclusion The small-world topology of complex functional network was affected by short-term MBSR training.The basal ganglia-thalamocortical circuits were mainly involved.Certain nodal property could reflect mindfulness skill and affective state.Current study may provide new clues about how brain functional topology was effected by MBSR.