Study Of Event-related Potentials In Schizophrenia Based On Working Memory

?Objective?Based on event-related potential technology and cognitive function assessment,the study explored the working memory status and the electrophysiological mechanism of working memory impairment of first-episode schizophrenia patients,and to search for cognitive and electrophysiological indicators of diagnostic value for schizophrenia.?Methods?Since January 2017 to December 2018,31 patients with first-episode schizophrenia were consecutive sampling from the Second Affiliated Hospital of Jining Medical University,and 30 normal controls were recruitment in Jining.To evaluate the cognitive function of first-episode schizophrenia patients and normal control group by using the Chinese version of MCCB,and to analyze the correlation between cognitive function and clinical symptoms.Change detection task were used to compare the behavioral outcomes and the status of contralateral delayed activity?CDA?,N1 and N2pc,as well as the correlation between N2pc and CDA under high and low loads.The dot pattern expectancy task was used to compare the behavioral results and the status of the contingent negative variation?CNV?between the two groups.The results of event-related potentials and cognitive function tests were compared between the two groups by t-test.EEG data were analyzed by variance analysis of repeated measurements designed data.The correlation analysis and multivariate linear stepwise regression analysis were used to analyze the relationship between event-related potential?ERP?index,cognitive function test results and clinical symptoms.?Results?1.The results showed that the first-episode schizophrenia patients had impairment in seven psychological dimensions of the Chinese version of MCCB,including speed processing,attention/vigilance,working memory,verbal learning and memory,visual learning and memory,reasoning and problem-solving ability,and social cognition?P<0.05?.The general score of PANSS was negatively correlated with the scores of symbol encoding test and semantic fluency test?P<0.05?.2.When performing change detection task,behavioral results showed that the correct rate of first-episode schizophrenia patients decreased,reaction time prolonged?P<0.05?,and the amplitudes of CDA and N2pc were lower than those of normal controls at high load?P=0.033,P=0.011?.The amplitudes of CDA and N2pc in first-episode schizophrenia patients were higher at high load than at low load?P=0.025,P=0.048?,and the amplitude difference of N2pc and CDA was positively correlated at high and low load?R=0.578,P<0.01?.3.When performing the dot pattern expectancy task,behavioral results showed that the errors of AX,AY and BX were higher in the first-episode schizophrenia patients group than that in the normal control group?P<0.05?.Compared with the normal control group,there was no difference in CNV_A amplitude,CNV_B amplitude and CNV_B-A amplitude?P>0.05?.The results of correlation analysis between CNV amplitude and behavioral data of first-episode schizophrenia patients showed that there was correlation between CNV_B and E_BX-AY,CNV_B-A and E_BY in CPZ lead?P<0.05?.4.The average amplitude of CDA and the 3D score of continuous operation test under high load may be relatively stable biological indicators for first-episode schizophrenia,and the combination of the two may be an early diagnostic indicator for schizophrenia.?Conclusion?1.First-episode schizophrenia patients have comprehensive cognitive impairment.Working memory impairment is one of the early cognitive impairments.2.The working memory of first-episode schizophrenia patients is impaired when performing change detection task and the dot pattern expectancy task,which is mainly manifested in the impairment of initial attention and selective attention,poor goal maintenance ability and interference control ability.3.The average amplitude of CDA and the 3D score of continuous operation test under high load may be relatively stable biological indicators for first-episode schizophrenia,and the combination of the two may be an early diagnostic indicator for schizophrenia.