急性疼痛与慢性疼痛对奖赏加工的影响及神经机制

疼痛和奖赏能够为个体提供不同的行为动机和主观价值体验,寻求奖赏和避免疼痛对于生存都很重要。疼痛可划分为急性疼痛和慢性疼痛,奖赏可区分为预期阶段的动机成分和体验阶段的享乐成分。奖赏对疼痛的抑制作用已经被广泛证实,但关于疼痛对奖赏的影响,目前的研究结果并不一致。因此需要进一步区分并探究急性疼痛与慢性疼痛对奖赏加工不同阶段的影响,分析两种疼痛对奖赏加工产生不一致影响的现象。这种现象出现的原因可能与急性疼痛向慢性疼痛转变过程中出现的奖赏加工能力缺陷有关。未来可以考虑从改善奖赏加工能力缺陷的角度进行检测和治疗,提前预防急性疼痛向慢性疼痛转变。     

Cues produced by reward and nonreward and temporal cues influence responding in the intertrial interval and to the conditioned stimulus

Rats in a Pavlovian situation were trained under three different reward schedules, at either a 30 s or a 90 s intertrial interval (ITI): Consistent reward (C), 50% irregular reward (I), and single alternation of reward and nonrewarded trials (SA). Activity was recorded to the conditioned stimulus (CS) and in all 10 s bins in each ITI except the first 10 s bin. Responding increased progressively over the bins of the 90 s ITI indicating a role for temporal cues in the ITI. Single alternation patterning (SAP), more vigorous responding on rewarded than on nonrewarded trials, occurred in the ITI as well as to the CS and differed little at the 30 s and 90 s ITI. The occurrence of SAP to the CS and, as shown here for the first time, in the ITI along with the findings for the C and I schedules, indicate three matters of importance. First, along with other cues such as temporal cues, behavior is influenced by cues associated with reward and nonreward both in the ITI and when the CS is presented. Second, as the percentage of reward associated with these cues increases so too does vigor of responding. Finally, if the cues produced by reward events are memories the retrieval cues for such memories are present in the ITI as well as when the CS is presented. Considerations are advanced indicating that reward produced cues may influence responding in the Pavlovian situation not only under regular schedules such as the SA schedule, but under all schedules. Indeed, such cues may more validly signal reward and nonreward than the CS itself.     

奖惩线索对停止信号任务中抑制能力和心率、皮肤电的影响

采用不同类型强化刺激(中性刺激,奖励刺激,惩罚刺激,以及奖励、惩罚刺激并存)来改变可获得奖励和惩罚的强度和频度,分别考察不同类型强化条件对停止信号任务中抑制能力、心率和皮肤电的影响.结果显示:与奖惩混合条件相比,在奖励条件下,被试的反应速度快,但正确抑制率明显低于惩罚条件和奖惩混合条件;在奖励条件下,被试在任务完成过程中的心率明显高于反馈条件、惩罚条件和奖惩混合条件.四种条件下被试的皮肤电活动无差异.     

Memories of reward and nonreward regulate the extinction and reacquisition of both excitatory and inhibitory associations

The memories of the unconditioned stimulus (US) and its absence (No US), symbolized as S^R and S^N, respectively, may be retrieved on US or No US trials giving rise to four types of associations, S^R → US, S^R → No US, S^N → US, and S^N → No US. Here, following acquisition under partial reward (PRF), rats were shifted either to different schedules of PRF (Experiment 1) or extinction (Experiments 1 and 2). Inhibitory S^R → No US associations formed in acquisition survived extinction and shifts to one, but not another type of PRF schedule (Experiments 1 and 2). Excitatory S^R → US associations also survived extinction (Experiment 2). These findings, as well as the acquisition findings of Experiment 2, are consistent with the sequential model but not with the only other two theories said to be able to explain PRF findings, the frustration hypothesis of Amsel and the attention hypothesis of Mackintosh [see Haselgrove, M., Aydin, A., & Pearce, J. M. (2004). A partial reinforcement extinction effect despite equal rates of reinforcement during Pavlovian conditioning. Journal of Experimental Psychology: Animal Behavior Processes, 30, 240–250]. Also, the reacquisition findings obtained here are inconsistent with two views applied to several learning phenomena, the rule-learning view and the position-item view.     

Effects of reward magnitude frames on measures of delay discounting in a hypothetical money scenario

The current study analyzed the effects of three frames of reward magnitude—quantity, volume, and duration—on the rate at which college students discounted hypothetical, delayed monetary rewards. Hypothetical scenarios were presented using the fill-in-the-blank discounting questionnaire and participants made choices between immediate and delayed hypothetical monetary rewards. Scenarios framed the monetary choices as (a) quantity of dollar bills, (b) height (inches) of a stack of dollar bills, and (c) duration of time spent in a hypothetical cash machine to collect dollar bills. For each scenario, participants' subjective values were used to calculate the area under the curve (AuC). Framing resulted in a moderate effect size: The duration frame yielded significantly smaller AuC values compared to the quantity and volume frames. Thus, the framing of reward magnitude was a significant variable in controlling discounting rates for hypothetical, delayed monetary rewards. Subsequent investigations should be aware of the independent effects of the reward magnitude frames on delay discounting rates.     

虚拟和真实金钱奖赏幅度对海洛因戒断者风险决策的影响

已有研究表明海洛因成瘾者风险决策能力受损, 但少有研究关注不同幅度金钱奖赏对戒断期海洛因成瘾者风险决策的影响以及这种影响是否会受到金钱奖赏类型的调节。因此, 本研究使用气球模拟风险任务(BART), 通过两个实验探究不同幅度虚拟和真实金钱奖赏对海洛因戒断者风险决策的影响。结果显示, 在虚拟奖赏情景下, 海洛因戒断者未爆破气球按键次数和爆破气球个数均显著大于正常组被试, 以及两组被试在25分奖赏条件下的未爆破气球按键次数和爆破气球个数均显著大于1分奖赏; 而在真实奖赏情景下, 海洛因戒断者未爆破气球按键次数和爆破气球个数均显著小于正常组被试, 以及两组被试在25分奖赏条件下的未爆破气球按键次数和爆破气球个数均显著小于1分奖赏。研究结果表明, 金钱奖赏类型和金钱奖赏幅度会影响被试的风险决策行为。在虚拟奖赏情景下, 两组被试的风险偏好水平随着奖赏幅度的增加显著升高, 但是戒断期海洛因成瘾者的风险偏好水平高于正常组被试; 而在真实奖赏情景下, 两组被试的风险偏好水平随着奖赏幅度的增加显著降低, 同时戒断期海洛因成瘾者的风险偏好水平低于正常组被试。     

Manipulating affective state influences conditioned appetitive responses

Affective states influence how individuals process information and behave. Some theories predict emotional congruency effects (e.g. preferential processing of negative information in negative affective states). Emotional congruency should theoretically obstruct the learning of reward associations (appetitive learning) and their ability to guide behaviour under negative mood. Two studies tested the effects of the induction of a negative affective state on appetitive Pavlovian learning, in which neutral stimuli were associated with chocolate (Experiment 1) or alcohol (Experiment 2) rewards. In both experiments, participants showed enhanced approach tendencies towards predictors of reward after a negative relative to a positive performance feedback manipulation. This increase was related to a reduction in positive affect in Experiment 1 only. No effects of the manipulation on conditioned reward expectancies, craving, or consumption were observed. Overall, our findings support the idea of counter-regulation, rather than emotional congruency effects. Negative affective states might therefore serve as a vulnerability factor for addiction, through increasing conditioned approach tendencies.     

Applying a logic of appropriateness to understand behavioral differences between common resource dilemmas and public good dilemmas

Common resource dilemmas (CRDs) and public good dilemmas (PGDs) are distinct types of social dilemmas, yet they model the same underlying conflict between the collective interest and one's self-interest. Here, we study and interpret behavioral differences between these two main types of social dilemmas by applying a logic of appropriateness. In two experiments, we argue and demonstrate that CRDs, relative to PGDs, evoke higher levels of cooperation, because taking from collective property (in CRDs) is generally considered less appropriate than not giving from personal property (in PGDs). Importantly, these differential considerations of appropriateness are reflected not only in the willingness to cooperate but also in the willingness to punish and reward others' (non)cooperative behavior. Taken together, the findings reveal that CRDs and PGDs elicit different norms of appropriateness.     

奖赏预期对选择性注意的影响——基于客体和空间的注意的区别

为了探究奖赏预期对选择性注意的影响,结合金钱激励延迟任务和双矩形范式,通过两个实验分别考察了奖赏预期的有无以及高低对选择性注意的影响。实验结果表明,在有奖赏预期的情况下,选择性注意更快,奖赏预期的有无对基于空间的注意影响区别不大,但奖赏预期几乎消除了基于客体的注意效应。在低奖赏预期条件下,基于客体和空间的注意均存在;而高奖赏预期条件下,基于空间的注意仍然存在,基于客体的注意几乎被消除了。结果表明奖赏预期可以影响选择性注意,并对基于空间和客体的注意产生不同影响。     

奖赏和损失情境下男性海洛因戒断者的风险决策缺陷

摘 要 采用修改版的多伦多赌博任务考察决策情境对海洛因戒断者风险决策的影响。研究结果主要发现,海洛因戒断者在损失情境下的风险寻求决策比率与吸毒年限显著正相关,这种相关提示了风险决策背景下海洛因成瘾者持续使用毒品与其较低的损失敏感性之间的复杂交互作用。其次,海洛因戒断者在做出风险决策后收到消极反馈时的风险规避倾向可以负向预测其风险寻求决策比率,这可能进一步反映了海洛因戒断者风险感知的钝化或其对消极反馈信息的整合加工存在异常。