Abstract: Objective To investigate the changes of non-linear dynamics characteristics of electroencephalogram(EEG) in patients with the stagnation of Liver-Qi syndrome.Methods 15 Liver-Qi stagnation syndrome patients and 15 normal persons were paired by sex and age.The data of EEG under three states(eyes closed,eyes opened,and mental arithmetic with eyes opened) were analyzed by the parameter of point-wise correlation dimension(PD₂).Results PD₂ of the stagnation of Liver-Qi syndrome group increased significantly compared with that of the healthy control group and always maintain high level.The difference of PD₂ between two groups was gradually reduced along with the increase of stimulated condition.Conclusion Non-linear dynamic analysis is more appropriate for the study of mental functions changes of stagnation of Liver-Qi syndrome and can be used to investigate the brain mechanism of the stagnation of Liver-Qi syndrome.

Key words: stagnation of Liver-Qi syndrome, electroencephalogram, non-linear dynamics, point-wise correlation dimension