The primary explore of the damage of the executive control network in major depressive disorder:a dynamic causal model on magnetoencephalography / 中华行为医学与脑科学杂志

ABSTRACT

Objective To investigate the interconnection of the executive control network in major depressive disorder when they recognized the sad facial stimuli,and to discuss the aberrant mechanism of emotion processing.Methods Twenty major depressive patients and 20 well-matched healthy volunteers participated in the experiment.The brain actions of all subjects were recorded by the magnetoencephalography (MEG) when they were required to distinguish the emotion face.Based on prior knowledge,the interested brain area consisted of the primary visual cortex (V1),the orbitofrontal cortex(OFC),the dorsolateral prefrontal cortex (DLPFC),the anterior cingulated cortex (ACC).Then constructing three competing models to select an optimal model by the method of dynamic causal model(DCM),finally the differences of the effective connections of the optimal model between the depressed patients and healthy controls were analyzed.Results According to the results of Bayesian model selection (BMS),model 1 had the most exceedance probability of 0.80 with the features that there were bidirectional modulatory connections between the OFC,ACC and DLPFC.Given the best model,the parameters of effective connectivity of the optimal model were extracted,and then two-sample t-test over the model 1 was adopted.The modulatory effective connectivity from the OFC to the DLPFC in both hemisphere(t=-2.73,P=0.0096;t=-3.01,P=0.0046) and the OFC to the ACC (t=-2.93,P=0.0057) in the left hemisphere were significantly reduced in MDD.Conclusion There exists abnormal function of executive control network in depressed patients,the decreased effective connections between the OFC and the DLPFC,as well as the OFC and the ACC,may have correlation with the negative