An ERP Study Of Reward Processing Sensitivity In Methamphetamine Addicts

Drug addiction has become a very serious issue in the society.Due to the long-term use of drugs,the addicts’ reward processing system are damaged,which leads to a decrease in the sensitivity of the addicts’ processing reward stimulus.The drugs effect on cognitive processing functions of addicts is an important topic in psychological research.Research applying drug-related stimuli usually uses it as a cue to explore whether drugrelated cues can arouse addicts’ attention bias rather than applying drug-related stimuli directly as a reward feedback in experimental tasks.Therefore,when the drug-related stimulations are used as rewards,the reward responses effects of the addicts can be triggered or not still needs to be verified.This experiment uses the simple gambling task.Two components,the Feedback-related negativity(FRN)when participants receiving the feedback and the P300 when participants viewing the pictures,are used as the EEG indicators in order to examine various types of processing methods,including monetary rewards,positive picture rewards and drug pictures rewards of the addicts and the normal people.Experiment 1 uses monetary reward to examine whether the two groups were sensitive to monetary reward feedback.The results showed that the processing sensitivity of the methamphetamine addicts to the monetary reward is significantly lower than the control group.In Experiment 2,positive emotion pictures are used as rewards to examine whether the two groups of people were sensitive to emotional pictures reward feedback.The results showed that the attention and processing sensitivity of the addicted group to the positive emotion pictures was significantly lower than the normal people,and the attention resource input of the addicted group when watching the positive emotion pictures was significantly lower than the control group.Experiment 3 uses drug-related pictures as a reward to see whether the two groups were sensitive to drug image reward feedback.The results showed that there was no significant difference in the attention and processing sensitivity between the drug addicts and the normal people,but the attention resource input of the addicts when viewing the drug pictures was significantly higher than the normal population.Based on the above experiments,the study concluded that the sensitivity of ice addicts to the processing of normal rewards decreased,showing the level of attention to money rewards and positive emotional picture rewards,processing sensitivity is lower than the normal population;The drug-related pictures show a tendency to reward processing.It seems that watching drug-related pictures is not a reward for addicts,but the amount of attention paid to the drug pictures is significantly higher than that of the normal population,so no reward processing is shown.The reason for the tendency may also be due to the special reward processing method of the addicted group,so that the addict only pays attention to the picture,and does not pay attention to the positive and negative feedback information,so whether the drug-related stimulation is a reward for the addicts,still need future research to prove.