RESUMO
Objective To analyze the difference of frontal-cingulate functional connection between patients with major depression and healthy controls in recognization of sad facial expression, and discuss the neutral basis of emotional bias in preliminary. Methods 12 female patients with major depression and 12 matched healthy controls were scanned. The intensities of brain activation in the process of sad and neutral facial expression recognition were analyzed, and the strengths of frontal-cingulate functional connection were compared between the two groups based on dynamic causal modeling. Results Comparing the stimulus adjusting connection models with Bayesian model indicated that model Ⅱ matched with the observation data better. In the comparison between model Ⅱ and model I ,the average Bayes factor was more than 7.38. In the comparison between model Ⅱ and model Ⅲ,the average Bayes factor was more than 2.71. Calculating the intrinsic connection parameters and stimulus adjusting connection parameters based on intrinsic connection model and stimulus adjusting connection model( model Ⅱ ), the result showed that connection strength between anterior cingulate and right inferior frontal gyrus in depression was greater than that in healthy controls. Conclusion The frontal-cingulate functional connection of patients with major depression is increased abnormally ,which may be the neural basis of negative emotional bias.