认知与发展心理学研究室知识库

摘要成瘾的一个主要特征是正常的奖赏和惩罚机能发生改变。研究奖惩的神经机制通常考察两个不同的阶段：奖惩预期和奖惩体验。由于两个阶段反映了不同心理状态，对人类行为有着不同的影响。因此需要分别考察这两个阶段来理解奖赏和惩罚加工的神经机制。在奖惩预期阶段，研究者通常考察cue-P3、关联性负变（contingent negative variation, CNV）、刺激前负波（stimulus-preceding negativity, SPN）；在奖惩体验阶段，研究者通常考察奖赏正波（RewP）和feedback-P3（fb-P3）。本研究使用ERP来研究冰毒使用障碍个体在金钱奖赏延迟任务（monetary incentive delay task, MID）中奖赏和惩罚的预期和体验相关的神经生理机制。19名女性冰毒使用障碍个体和20名女性健康对照组被试分别在计算机上完成MID任务，首先给被试呈现奖赏、惩罚或中性条件线索，之后让被试完成一个快速按键任务，在不同诱因线索条件的试次中，按键成功或失败分别对应不同的金钱奖励或惩罚。实验过程中同时记录被试的脑电数据。结果发现，在反映奖赏预期的cue-P3指标上，冰毒使用障碍个体显著高于健康对照组；在反映奖赏预期的CNV指标上，冰毒使用障碍个体与健康对照组没有差异；在反映奖赏预期的SPN指标上，冰毒使用障碍个体在奖赏线索条件下显著高于惩罚和中性条件，而健康对照组没有这种诱因效应；在反应奖惩体验的FRN指标上，冰毒使用障碍个体在奖励条件和惩罚条件下均显著高于健康对照组；在反映奖赏体验的fb-P3上，健康个体在赢条件下显著高于输的条件，而冰毒使用障碍个体在赢和输的条件下没有显著差异。结论是，在预期阶段，冰毒使用障碍个体的奖励线索诱发的预期相关神经活动强于对惩罚线索诱发预期相关神经活动；体验阶段，冰毒使用障碍个体对赢或输的神经反应没有差异。这表明冰毒使用障碍个体一方面表现出奖励期待的神经反应增强，但另一方面，对输赢的神经反应区分能力下降。这可能是导致成瘾个体在失败体验后仍然继续使用药物的神经基础。

Abstract： A major feature of addiction is the change in normal reward and punishment functions. The neural mechanisms for studying reward and punishment usually look at two different stages: anticipation and outcome stages. Since the two stages reflect different mental states, they have different effects on human behavior. Therefore, it needs to examine these two stages separately to understand the neural mechanisms of reward and punishment processing. In the anticipation stage of reward and punishment, researchers usually examine cue-P3, contingent negative variation (CNV), and stimulus-preceding negativity (SPN). In the stage of reward and punishment outcome, researchers usually examine reward positivity (RewP) and feedback-P3 (fb-P3). In the current study, a monetary incentive delay task (MID) was used to study the neurophysiological mechanisms associated with the anticipation and outcome of rewards and punishments for individuals with methamphetamine use disorder. Nineteen female methamphetamine use disordered individuals (MA) and 20 female healthy control subjects (HC) completed the MID task on the computer respectively. Firstly, the participants were presented with rewards, punishments or neutral conditional clues, and then they should press a button task as soon as they can. In the trial of the incentive clue condition, the success or failure of the button press corresponds to different monetary rewards or penalties. The EEG data of the subjects were recorded simultaneously during the experiment. The results showed that the cue-P3 reflecting the reward anticipation in MA group was significantly higher than the HC group; in the CNV reflecting the reward anticipation, there was no difference between the MA group and the HC group; In the SPN reflecting the reward anticipation, the reward cues condition was significantly higher than the penalty and neutral conditions in MA group, while HC group did not have this incentive effect; in the FRN reflecting the reward and punishment outcome, the MA group was significantly higher than the HC group under the reward and penalty conditions; on the fb-P3 reflecting the reward outcome, the win condition was significantly higher than the lose condition in the HC group, while no significant difference between winning and losing conditions in the MA group. It is concluded that in the anticipation phase, the anticipation related neural activity induced by the reward cues is stronger than the anticipation related neural activity induced by the penalty cues in methamphetamine use disordered individuals; in the outcome stage, there is no difference in the neural response under winning or losing conditions in methamphetamine use disordered individuals. This indicates that on the one hand, the individual with methamphetamine use disorder shows an increase in the neural response under rewards anticipation stage, but on the other hand, the ability to distinguish the neural response to the winning and losing is reduced. This may be the neural basis for the addicted individuals to continue using the drug after the failure experience.