The Study Of The Heroin Addicts' Impulsivity And Risk-taking Decision-making Characteristics Under The Reward And Punishment Situations

Including heroin addicts,the drug addicts are more likely to choose small reward in time than large delayed reward,and more likely to choose high reward with low probability than small reward with high probability.Research shows that impulsivity and risk-taking are two important factors that cause decision-making defects of drug addicts.Current studies mainly focus on the influence of drug-related cues on the cognition and decision-making function of drug addicts,but ignore the influence of reward and punishment cues on drug addicts.Incentives of rewards and punishments are the main means to shaping ones behaviors and also the important factors that can affect individual decision-making behaviors.According to Reinforcement Sensitivity Theory,punishment has an inhibitory effect on impulsive behavior,while reward enhances individual's impulsivity behavior.According to the hypothesis of Prospect Theory,individuals tend to risk-taking in the loss(punishment)situation and to avoid risks in the gain(reward)situation.Drug addicts have the characteristics of impulsivity and risk-taking,but in this background it is not clear how the incentive situation of reward and punishment to affects the decision-making behavior of drug addicts.So this study intends to investigate this problem through two experimental scenarios.In experiment 1,heroin addicts and normal subjects were selected as the research objects,and Floden card task was used to investigate the decision-making performance of the two groups in the situation of neither reward nor punishment.The results showed that there was no significant difference in the number of individuals with impulsive decision making and risk-taking decision making between the two groups.In experiment 2,heroin addicts and normal subjects were selected as the research objects,and Floden card task was used to investigate the decision-making performance in the situations of reward and punishment.In the reward situation,the two groups had no significant difference in the composition ratio of the three decision types,which were risk-taking,impulsivity and non-obvious decision characteristics.However,the number of individuals with the impulsivity decision characteristics in heroin group was significantly higher than that with the risk-taking decision characteristics and non-obvious decision characteristics,so the impulsivity decision characteristics were prominent in the reward situation.But,there was no significant difference in the number of individuals in the normal group.In the punishment situation,the two groups had no significant difference in the composition ratio of the three decision types,which were risk-taking,impulsivity and non-obvious decision characteristics.However,the number of individuals with the risk-taking decision characteristics in heroin group was significantly higher than that with the impulsivity decision characteristics and non-obvious decision characteristics,so the risk-taking decision characteristics were prominent in the punishment situation.But,in normal group there was no significant difference in the number of these two decision characteristics.Based on the results of the two experiments,the research show that in terms of risk-taking characteristics,in punishment situation the two groups of subjects with risk-taking decision characteristics were significantly greater than that in the reward situation and neutral stimulus situation,both heroin addicts and normal subjects showed increased risk-taking preference in decision-making.In terms of impulsive decision characteristics,in reward situation,the heroin groups with impulsive decision characteristics were significantly greater than the number in punishment.However normal group in these three types situation which were rewards,punishments and neutral stimulus situation had no significant difference.The above results show that in the reward and punishment situation heroin addicts are swayed by considerations of gain and loss,that is,impulsivity in reward and risk-taking in loss.This suggest that compared with normal subjects,heroin addicts are more susceptible to external reward and punishment stimuli,neither can stand the "temptation" nor can bear the "loss".This may be one of the reasons why they initially try addictive drugs and continue to relapse.