| Objectives To explore the characteristics of attention bias of depression patients to sad emotional stimuli through response time index.Event-related potentials(ERPs)were used to analyze P100 and N170 evoked by different emotional faces,and to explore the characteristics of the early stage of perception processing in patients with depression.Methods Thirty patients with first episode depression in a psychiatric hospital were selected as the depression group,and thirty non-depression patients were selected as the control group for the study.The general information of the two groups,such as gender,age,education level and marital status,was matched.All participants were required to wear 128-lead EGI equipment for dot probe task testing,recording the reaction time and EEG data during the experiment.The experimental data were analyzed and compared by chi-square test,t-test and repeated measurement analysis of variance.Results 1 The results of response time data analysis of depression group and control group were as follows.The response time of the depression group was significantly longer than that of the healthy control group(F(1,58)=5.871,P=0.019).The main effect of the picture presentation time was significant.When the picture presentation time was 500 ms,the response time was significantly longer than the reaction time when the picture presentation time was 100ms(F(1,58)=6.037,P=0.017).All participants showed no attention bias,attention orientation and attention relief difficulties to negative emotional stimuli(P>0.05).2 The results of P100 amplitude data analysis of depression group and control group were as follows.There was no significant difference in P100 amplitude between the depression group and the healthy control group(P>0.05).The main effect of picture presentation time was observed(F(1,58)=4.810,P=0.032).The P100 amplitude when the picture is presented at 500 ms is obviously larger than that when the picture is presented at 100 ms.The main effects of the remaining factors were not significant.3 The results of P100 latency data analysis of depression group and control group were as follows.There was no significant difference in P100 latency between depression group and healthy control group(P>0.05).The interaction effect of experimental group × brain regions × image presentation time was significant(F(1,58)=4.861,P=0.031).The latency of P100 at the left occipital region was longer than that at the right occipital region in the depression group when the picture presentation time was 100 ms.The interaction effect of experimental group ×picture properties was significant(F(1,58)=5.952,P=0.018).In the healthy control group,the P100 latency induced by sad emotional faces was longer than that induced by neutral faces.The main effects of the remaining factors were not significant.4 The results of N170 latency data analysis of depression group and control group were as follows.The amplitude of N170 in depression group was significantly lower than that in healthy control group(F(1,58)=7.223,P=0.009).The main effect of picture presentation time was observed(F(1,58)=9.826,P=0.003).The N170 amplitude when the picture is presented at 100 ms is obviously larger than that when the picture is presented at 500 ms.The main effects of the remaining factors were not significant.5 The results of N170 amplitude data analysis of depression group and control group were as follows.There was no significant difference in N170 incubation period between the depression group and the healthy control group(P>0.05).The main effect of picture presentation time was observed(F(1,58)=45.348,P<0.001).The N170 latency when the picture is presented at 500 ms is obviously larger than that when the picture is presented at 100 ms.The main effects of the remaining factors were not significant.Conclusions 1 In the dot probe task the response time of probe stimulation was prolonged in patients with depression.2 The prolongation of the presentation time of emotional picture stimuli will delay the brain’s response to subsequent probe stimuli.3 In the process of emotional picture perception,the prolongation of stimulus presentation time will lead to the increase of P100 amplitude.4 Decreased amplitude of early sensory component N170 in patients with depression.Figure1;Table5;Reference 120... |
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