Analysis Of Resting State EEG And ERP Microstates In Abstinent Heroin Addicts

Drug addiction has great harm to society,families and individuals.It is a social problem on a global scale.In our country,the number of heroin abusers is much higher than other types of drugs,and the situation is the most severe.Prolonged abuse of heroin can cause brain damage to addicts.Research on electroencephalograph(EEG)related to heroin addiction has been a hotspot in recent years.At present,there are more and more researches on EEG and event-related potential(ERP)microstates of various diseases,but the research on EEG and ERP microstates of heroin addiction is very scarce.Therefore,on the one hand,this thesis studies the characteristic parameters of resting state EEG microstates of abstinent heroin addicts(AHAs)from the perspective of microstate.On the other hand,it investigates the abnormality of ERP components and ERP microstates abnormalities caused by AHAs from drug cues.The aim is to understand more fully the effects of heroin addiction on brain damage and brain attention processing.The main research of this thesis is as follows:1.This thesis was based on eye-closed resting state EEG data of 33 AHAs and 29 healthy controls(HCs).And this thesis explored the differences in microstates characteristic parameters and topological maps of resting state EEG between AHAs and HCs.The characteristics of the EEG microstates mainly included the duration,the occurrence,the average percentage of time covered by each type of microstates,the probability of transition between microstates,and the bias of transition between microstates.Five months later,the EEG data of the 33 AHAs were collected under the same experimental conditions in order to explore the effect of abstinent duration on the EEG microstates.The results show that microstates A,B,C and D are finally obtained in the experiment.On the one hand,compared with the HCs,the duration of the microstate A and microstate D of AHAs is significantly shorter,and the occurrence of microstate A and microstate B is significantly higher.On the other hand,in the research on the transfer bias among microstates,it was found that there is a transferbias A→D→B→A between microstates in the AHAs,while the transfer bias between microstates in the HCs is A → B → D.The previous results indicate that heroin addiction caused abnormalities in EEG and microstates of AHAs.With the increase of abstinent time,the EEG microstates collected for the second time in AHAs were compared with the EEG microstates of the same HCs.It was found that the duration of microstate A is significantly shorter,and the occurrence of microstate B is significantly higher.The difference in microstate D disappears,indicating that forced withdrawal may change the microstates characteristics of AHAs.2.This thesis used the Dot-probe paradigm to study differences in behavioral data,ERP components and ERP microstates of 19 AHAs and 19 HCs under the conditions that target stimulation and addiction-related cues were consistent and inconsistent.It was found that AHAs have shorter response time under consistent conditions than inconsistent conditions,while HCs have the opposite response,which confirms that AHAs have a attention bias to addiction cues.The study of ERP induced by target stimulation found that compared with HCs,the amplitudes of N2 and P3 induced by AHAs are larger,and the latency of P3 is earlier.And the latency of P300 under the inconsistent conditions is significantly earlier than the consistent case of AHAs.This may be due to an abnormality in the assessment and processing of point stimuli caused by the addiction group’s attention bias toward addictive cues.From the analysis of the microstates of ERP between groups,it can be seen that the types or occurrence time of microstates between the two groups show differences within the N2 and P3 time windows.In the addicted group,the same microstates appeare in both conditions.But the microstates appeare earlier than the consistent condition under inconsistent conditions in the P3 time window,which may be related to its earlier latency.Through the above research,it found that there are differences in the characteristics of EEG microstates between AHAs and HCs.At the same time,it was found that AHAs have attention bias to addiction-related clues and differences of ERP can be corroborated by microstates results.These results help to a better understanding of the heroin addiction mechanism in the future.At the same time,it has been confirmed that the characteristic indicators of microstates can provide new ideas and insights for brain research on heroin addiction.