An ERP Research On Time Discounting Phenomenon In Specific Population

Objective:The aim of this study was to record the EEG EEG signals and extract the P300 components of the event-related potentials through the ERP workstation through the classical experimental paradigm test of the time discounting phenomenon in schizophrenic patients and healthy people.Thus:(1)the difference of behavioral operation between normal subjects and schizophrenic patients in time discount task was analyzed,and the difference of the components and indices of brain evoked potentials caused by ERP was analyzed and compared,and the neurological mechanism of cognitive impairment in schizophrenic patients was further discussed.Methods:The classical hypothesis reward experiment paradigm with time discounting,to enable the normal subjects(n=30)and schizophrenia(n=30)to complete the different levels(large amount,small amount)and different delay time(today and 6 months,1 months,2 weeks,1 days)under the conditions of the delayed benefit behavior selection task,The EEG signals and the behavior data of the subjects were recorded simultaneously.After the data was processed off-line,the differences of behavior between the two groups were analyzed and compared,to analyze and compare the effects of schizophrenia on the P300 component indices of event-related potentials.Results:(1)(1)Using the group*amount of two factors mixed design variance analysis to test the data,the results show that the amount of the main effect is significant (f=5.867,p<0.05,η~2=0.092,large amount of choice is now significantly smaller than the small amount),the group main effect is not significant(f=0.320,p=0.574),the interaction between them was significant(f=15.450,p<0.01,η~2=0.210),and the results showed that the proportion of case group selection was significantly smaller than that in the control group under the condition of large amount data.But under the small amount condition,the proportion difference between the two groups is not significant.The other side of the simple effect of the analysis result is that the large amount of cases in the selection of the current ratio is significantly smaller than the small amount,but the control group two of the amount of the choice of the current proportion of the difference is not significant.(2)using the group*Time two factors mixed design variance analysis to test the data.The results showed that the time main effect was significant (f=33.665,p<0.01,η~2=0.643),the difference between the current ratio 22 was significant,6 months,1 months,two weeks and 1 days.The group main effect was not significant(f=0.325,p=0.571),and the interaction was significant(f=7.572,p<0.01,η~2=0.289).A further simple effect analysis of interaction results showed that the proportion of case group selection was significantly lower than that in the control group after 1 days,but the difference was not significant between the two groups under other time conditions.The other side of the simple effect analysis result is that the proportion of the case group selected now is significantly different from these groups(6 months,1 months,two weeks,1 days),however,the proportion of the subjects selected now was significantly smaller than that of other time groups after 1 days,and after 1 months significantly less than 6 months,the difference was not significant among other groups.(3)The event-related potential P300 latency(350.843±38.934ms)in the case group was significantly longer than that in the control group(319.477±23.065MS),the difference was statistically significant(t=2.708,p<0.05),and the P300 amplitude of the case group(3.957±2.116uv)was significantly lower than the control group(5.248±2.553uv),and the difference was statistically significant(t=3.410,p<0.01).(4)The average amplitude in the 275ms~350ms interval after the stimulation of the C_Z pole is taken as data,and the results show that the main effect is insignificant(f=0.558,p=0.979>0.05)and the group main effect is significant(f=2.737,p=0.001<0.01),the amount*Group interaction is not significant(f=0.622,p=0.950>0.05).Conclusion:(1)The change of the length of time has a significant effect on the behavior choice of schizophrenic patients,the longer the time,the more the subjective value of the event decreases;(2)The P300 amplitude of event-related potentials in schizophrenic patients was different from that of healthy subjects in latency,amplitude and the average amplitude in the interval.The latent period was longer and the amplitude was lower,which suggested that the cognitive function of schizophrenic patients was impaired.