The Preattentive Processing Of Complicated Music Chords In Patients With Major Depressive Disorder:an Event-Related Potential Study

Objective:Major depressive disorder (MDD) is one of the most common psychiatric diseases which was characterized by ahedonia and lack of interest.Music therapy has been proved to be a valuable valuable alteration for the treatment of MDD. However,the relation among emotion,music and brain has been unknow yet. Most of the previous studies have showed that the patients with MDD might have dysfunction of emotional information processing.Music as a kind of stimulate material which could affect people’s emotion,might have deficit during one’s pre-attentive processing of auditory musical information among MDD.The present study aims to explore the automaic processing of consonance and dissonance music chords in patients with MDD by Event-Related Potential(ERP) technology.And the ERP component we analys is Mismatch Negativity(MMN).Methods:The participants in the study included 14 MDD patients and 12 healthy volunteers.Both of them were age,sex,years of education,and intelligence matched.All of the patients conformed to the diagnostic criteria of DSM-IV for MDD.All participants finished Hamilton Anxiety Rating Scale(HAMA) and the 17-item Hamilton Rating Scale of Depression(HRSD-17) before the experiment.The paradigm we used in the experiment is a Reverse-oddball paradigm.The stimulus we used are complicated music chords which include consonance and dissonance music chords.During the process of experiment,subjects should neglect auditory stimulus,and watch silent movies.All of the electroencephalogram were recorded throughout the whole test.The amplitudes and the latency of MMN were measured at central eletrode(C3、Cz、C4) and frontal eletrode(F3、FZ、F4).The repeated-measures analysis of variance was used to compare the MMN between the two group.The correlations between the amplitudes of MMN and age,years of education,course of the disease,HRSD-17 and HAMA scores among MDD patients were analyzed by Pearson correlations.Result:1.The analysis of the amplitude of MMN:There was a significant main effect of stimulus type within healthy control group (F(1,22)=6.404,p=0.019).This difference was significant among MDD group (F(1,26) =5.125,p=0.032)There was no significant main effect of group for MMN evoked by consonance music chords(F(1.24)=0.171,,p=0.683).The MMN amplitude revealed a significant main effect of region (F(1,24)=4.349,p=0.048),and frontal area is larger than central area. The MMN amplitude revealed a significant main effect of hemisphere (F(1,24)=4.641, p=0.029),and left hemisphere is larger than right hemisphere.There was a interaction of group type X hemisphere (F(1,24)=4.481,p=0.032).In healthy control group,the MMN revealed a largest amplitude at left hemisphere.There was no significant difference in MDD group.The MMN evoked by dissonance music chords also show non-significant main effect of group (F (1,24)=0.024,p=0.879). There was a interaction of group type X hemisphere (F(1,24)=4.120,p=0.022).In healthy control group,the MMN revealed a largest amplitude at right hemisphere.However MDD group have no significant difference.2.There was no main effect of group for the latencies of MMN(ps>0.05).3. The amplitude of MMN was no correlation with age,years of education,course of the disease,HRSD-17 and HAMA scores among MDD patients(ps>0.05).Conclision:The study showed that MDD patients exhibited no significant deficit in automatic processing of consonance and dissonance music chords at the stage of pre-attentive,but there is an abnormal distribution of hemisphere among MDD patients at automatic processing of consonance and dissonance music chords.