真实和虚拟金钱奖赏影响风险决策行为*

在风险情境下人类如何决策是长久以来心理学和经济学研究中一个极具挑战性的核心问题。众多研究采用真实或虚拟金钱作为奖赏强化物来探索风险决策行为的过程和机制,但对金钱奖赏真实性如何影响决策了解很少。仿真气球冒险任务(BART：Balloon Analogue Risk Task)可以在实验室条件下有效评估个体在真实社会中的风险行为。本研究采用 BART任务,通过两个实验探讨和比较了真实与虚拟金钱奖赏对风险决策行为的影响。实验一的结果发现,与虚拟金钱奖赏相比,真实金钱奖赏情境下的风险决策更容易受上一次决策结果的影响,上一次决策失败会导致被试的风险偏好水平显著降低(平均吹气球的次数显著减少),同时决策失败(气球吹爆)次数也显著减少,提示真实金钱奖赏下有更强的反馈学习效应。实验二重复了实验一的结果,并进一步发现,虚拟金钱奖赏的幅度对被试的风险决策行为没有影响,而真实金钱奖赏的幅度能显著改变被试的风险决策行为,较大幅度的真实金钱奖赏可以显著降低被试的风险偏好水平,但这种奖赏幅度对风险偏好的调控效应只对感觉寻求水平低的被试有效,感觉寻求水平高的被试不受影响。这些发现表明真实与虚拟金钱奖赏对风险决策行为有不同的影响。我们的结果可以用风险决策的后悔理论或齐当别模型来解释。     

金钱崇拜对个体跨期决策偏好的影响

采用经典跨期选择任务范式,以个体的金钱喜好差异为切入点,通过问卷调查和行为实验考察金钱崇拜对个体跨期决策偏好的影响。结果发现:(1)个体的金钱崇拜水平与其跨期折扣倾向显著负相关;(2)无论跨期决策任务的难易和兑现时间的长短,高金钱崇拜者更倾向于选择较大的延迟奖赏,而低金钱崇拜者更倾向于选择较小的即时奖赏;(3)高、低金钱崇拜者的跨期决策反应时没有明显的差异,但二者的反应时都明显地受到任务难度的影响,即在容易条件下的反应速度显著快些。结果表明,个体的金钱崇拜水平在跨期决策过程中发挥着重要的作用,致使高金钱崇拜者更愿意等待延迟大奖赏的到来。     

奖赏预测误差对记忆辨别的影响：行为及眼动的证据

记忆辨别反映了个体对所经历事件能够形成独特的记忆表征并正确拒斥相似诱饵的能力,是情景记忆最重要的特征之一。研究采用奖赏条件学习范式和记忆相似任务考察奖赏预测误差对记忆辨别的影响。结果显示奖赏预测误差的绝对值越大,记忆辨别值越高;在诱饵击中项目中,高奖赏预测误差绝对值条件下的瞳孔扩张值（pupil dilation, PD）显著高于低绝对值条件;而在诱饵虚报项目中,两者无显著差异;瞳孔扩张值是记忆辨别的正向预测因子。综上,不带符号的奖赏预测误差能够引发个体的意外反应、提高其情绪唤醒水平（瞳孔扩张）、促进个体对细节信息的加工、提高记忆辨别。     

奖赏预期对面孔情绪加工的影响：一项事件相关电位研究

采用事件相关电位(ERPs)技术考察了奖赏预期对人类面孔情绪识别的影响。实验采用线索-目标范式, 分别记录了被试在奖赏预期条件下以及无奖赏预期条件下对正性、中性和负性面孔进行情绪辨别任务的ERP数据。行为结果显示, 被试在奖赏预期条件下的反应时快于无奖赏预期条件下的反应时, 对情绪面孔的反应时快于对中性面孔的反应时。ERPs数据显示, 奖赏线索比无奖赏线索诱发了更正的P1、P2和P300成分。目标刺激诱发的P1、N170波幅以及N300均受到奖赏预期的调节, 在奖赏预期条件下目标诱发了更正的ERPs。P1、N170、VPP等成分没有受到面孔情绪的影响, 而额中央位置的N300波幅显示情绪(正性与负性)面孔与中性面孔加工的差异。重要的是, N300波幅出现奖赏预期与情绪的交互作用, 正、负情绪加工效应以及负性偏向效应受奖赏预期的差异性影响。正性情绪加工效应不受奖赏预期的影响, 而负性情绪加工效应和负性偏向效应在奖赏预期条件下显著大于无奖赏预期条件下。这些结果说明, 奖赏预期能够调节对面孔情绪的加工, 且不同加工进程中奖赏对情绪加工的调节作用不同。动机性信息调节注意资源的分配, 促进了个体在加工面孔情绪时的负性偏向。     

应激对模糊决策的影响：认知和神经机制

模糊决策是指决策者无法预先知道结果发生的概率,只能依赖主观判断而进行的决策。应激会影响模糊决策,但不同研究结果并不一致,从模糊决策的认知成分入手能帮助我们更好地理解应激对模糊决策的影响。本研究从学习反馈、奖赏敏感性和风险偏好三个方面梳理了现有的行为和脑机制研究文献,发现应激对模糊决策的影响主要表现为应激导致反馈受阻、重赏轻罚、增加冒险三个方面。未来的研究应该关注应激类型和强度对模糊决策的不同影响,同时进一步拓展应激状态下模糊决策中认知与情绪的交互效应研究。     

不同特质自控者在跨期选择中自我损耗后效的差异

摘要 自我控制在跨期选择中起着重要的作用,个体自我控制资源损耗(简称自我耗损)会影响随后的决策行为。本研究利用双任务范式考察了自我损耗对不同特质自控者跨期选择影响差异。结果发现,自我损耗使低自控者在跨期选择中更倾向于选择较小即时奖赏,而对高自控者的跨期选择倾向没有显著影响。这些结果说明,状态自控对不同特质自控个体跨期选择的影响明显不同,本研究为不同自控特质个体更好地进行跨期选择提供一定的理论依据。     

焦虑对社会决策行为的影响

焦虑是在人类日常生活中常见的一种负性情绪。探讨焦虑情绪在个人生活和工作中扮演的角色, 是生理学界和心理学界的一项重要课题。过往研究显示焦虑水平的提高会对社会能力和社交技巧造成显著的影响。在社会决策领域中, 这种影响的具体表现是高焦虑者比低焦虑者更倾向于采取回避风险的策略。但是, 过往研究主要关心包含经济因素的社会决策, 而对其他类型的社会行为的探索存在不足。以下问题值得未来研究者们关注：在个体层面上, 高焦虑者是否会更容易受到外界信息的影响, 表现出更强的从众行为和权威依从倾向, 与他人进行社会比较或社会竞争的动机是否会被削弱？在群体层面上, 高焦虑者是否更容易表现出人际信任, 以及是否会表现出更强的服从集体倾向？考察这些问题将会为针对焦虑情绪的认知研究和临床研究起到促进作用。     

自动化情绪调节策略对特质焦虑大学生应激反应的影响

研究采用句子整理任务诱发自动化情绪调节策略,特里尔社会应激测试模拟应激过程,以探讨认知重评和表达抑制对不同特质焦虑倾向大学生在应激状态下的影响。结果发现,自动化认知重评和表达抑制能获得适应性生理反应。自动化情绪调节策略适用于不同特质焦虑倾向的个体。特质焦虑对个体应激反应的影响主要体现在情绪体验上,高焦虑特质个体更易体验到焦虑情绪。但个体在压力性任务中的生理反应和行为表现不受特质焦虑因素的影响。     

愤怒和悲伤情绪对助人决策的影响:人际责任归因的作用

基于具体情绪理论——评价倾向框架理论(ATF),采用两项研究考察负性情绪愤怒和悲伤对助人决策的影响,并探究人际责任归因在这一关系中的作用。两项研究均采用自传体情绪记忆任务诱发情绪,研究一中自变量情绪为组间变量,包括愤怒、悲伤和中性三个水平,因变量助人决策操作为为他人花费时间;研究二中自变量1为组间变量情绪,包括愤怒和悲伤,自变量2为组内变量人际责任归因,操作为模糊归因、不可控的情景归因、可控的自我归因三种情境,因变量助人决策操作为为他人花费金钱。结果发现:(1)与愤怒情绪相比,悲伤情绪下个体为他人花费的时间和捐助的金钱更多;(2)在模糊的人际责任归因条件下,悲伤个体会比愤怒个体捐助更多的钱。研究表明:同为负性情绪的愤怒和悲伤在助人决策上的作用不同,悲伤个体比愤怒个体做出更多的助人决策;人际责任性归因会影响附带情绪和助人决策的关系。研究结论有助于理解附带情绪对助人决策的影响,进一步丰富并延伸ATF理论的证据和领域,对发挥情境中人际责任归因在助人决策中的作用具有一定的现实意义。     

偶然情绪对延迟选择的影响机制

本研究旨在探讨偶然情绪对延迟选择的影响及影响机制。本研究包括两个实验, 在被试进行决策前, 分别采用图片和短片诱发其与当前决策任务无关的偶然情绪, 然后要求被试完成选择任务, 并从决策结果和决策过程两个角度考察偶然情绪对延迟选择的影响及影响机制。结果发现, 当可选项中不存在1个优势选项时, 与正性情绪相比, 个体在负性情绪下会更倾向于延迟选择, 而个体对决策信息的加工深度在偶然情绪对延迟选择的影响中具有中介作用。这可能是因为相比于正性情绪, 个体在负性情绪下会采用更深入的加工策略, 增加了决策难度, 进而提高了个体的延迟选择倾向。     

Dopaminergic and prefrontal contributions to reward-based learning and outcome monitoring during child development and aging

In many instances, children and older adults show similar difficulties in reward-based learning and outcome monitoring. These impairments are most pronounced in situations in which reward is uncertain (e.g., probabilistic reward schedules) and if outcome information is ambiguous (e.g., the relative value of outcomes has to be learned). Furthermore, whereas children show a greater sensitivity to external outcome information, older adults focus less on a rapid differentiation of rewarding outcomes. In this article, we review evidence for the idea that these phenomenologically similar impairments in learning and outcome monitoring in children and older adults can be attributed to deficits in different underlying neurophysiological mechanisms. We propose that in older adults learning impairments are the result of reduced dopaminergic projections to the ventromedial prefrontal cortex, which lead to less differentiated representations of reward value. In contrast, in children, impairments in learning can be primarily attributed to deficits in executive control, which may be due to a protracted development of the dorsal medial and lateral prefrontal cortices. We think that this framework maps well onto recent neurophysiological models of reward processing and is plausible from a broader developmental perspective.     

Information about foregone rewards impedes dynamic decision-making in older adults

“Making an informed decision” implies that more information leads to better decisions, yet it may be the case that additional information biases decisions in a systematic and sometimes detrimental manner. In the present study, we examined the effect of additional information on older adults’ decision-making using a task for which available rewards were dependent on the participant’s recent pattern of choices. The optimal strategy was to forego the immediately rewarding option in favor of the option that yielded larger delayed reward. We found that providing information about true foregone rewards – the reward that would have been received had the participant chosen the other option – significantly reduced older adults’ decision-making performance. However, false foregone rewards – foregone rewards manufactured to make the long-term option appear more immediately rewarding – led older adults to perform at a level equal to younger adults. We conclude that providing information about foregone rewards biases older adults toward immediate rewards at a greater rate than younger adults, leading to poorer older adult performance when immediate rewards and long-term rewards conflict, but intact performance when immediate rewards and long-term rewards appear to align.     

Money talks in attention bias modification: Reward in a dot-probe task affects attentional biases

Attention bias modification (ABM) aimed at correcting dysfunctional biases in anxiety patients has met with only mild success. Inspired by recent studies showing large effects of financial reward upon attention shifts, we contrasted effects of traditional dot-probe ABM and reward upon attention biases in a between-subject 2 × 2 design. Twenty-seven participants in group cognitive behavioural therapy (GCBT) for social anxiety disorder (SAD) were randomly assigned to undergo six sessions of a dot-probe task consisting of ABM or placebo ABM along with random or high reward following neutral stimuli. There was no influence of ABM on participants' attention bias over and above the influence of GCBT. Reward, however, had a strong influence on attention bias. Neither ABM nor reward reduced SAD symptoms over and above the effects of GCBT. The results add to the growing evidence that benefits of ABM through dot-probe training are unreliable but suggest on the other hand that rewarding attention may strongly influence dysfunctional attention biases.     

The effect of monetary incentives on backward digit span performance

In order to determine if monetary-incentive effects, particularly the detrimental effects of such incentives on human learning and performance, might be mediated by anxiety, 52 college students were administered six backward digit trials in a preexperimental, baseline phase and six trials in an experimental, test phase. Of the 52 subjects, 26 were paid 50 cents following each correct recitation of a backward digit series during the test phase. The remaining 26 were unpaid control subjects. Results showed that the rationale for the study was correct because state anxiety was indeed negatively related to backward digit span performance as previous research had shown, but the offer of reward did not elevate state anxiety scores and, more importantly, the offer of reward led to a significant improvement in backward digit span performance—an effect which is the opposite of what would be predicted by the anxiety hypothesis. The reward effects of theoretical interest in planning this research were those facilitating and detrimental effects that are produced by offering elementary, high school, or college students small amounts of money (typically from $1 to $3) as a superfluous inducement to participate in a study of human learning or performance. The results of this study discredit any explanation of such reward effects which attributes the effects to reward-induced anxiety.     

Reinforcement learning in the brain

A wealth of research focuses on the decision-making processes that animals and humans employ when selecting actions in the face of reward and punishment. Initially such work stemmed from psychological investigations of conditioned behavior, and explanations of these in terms of computational models. Increasingly, analysis at the computational level has drawn on ideas from reinforcement learning, which provide a normative framework within which decision-making can be analyzed. More recently, the fruits of these extensive lines of research have made contact with investigations into the neural basis of decision making. Converging evidence now links reinforcement learning to specific neural substrates, assigning them precise computational roles. Specifically, electrophysiological recordings in behaving animals and functional imaging of human decision-making have revealed in the brain the existence of a key reinforcement learning signal, the temporal difference reward prediction error. Here, we first introduce the formal reinforcement learning framework. We then review the multiple lines of evidence linking reinforcement learning to the function of dopaminergic neurons in the mammalian midbrain and to more recent data from human imaging experiments. We further extend the discussion to aspects of learning not associated with phasic dopamine signals, such as learning of goal-directed responding that may not be dopamine-dependent, and learning about the vigor (or rate) with which actions should be performed that has been linked to tonic aspects of dopaminergic signaling. We end with a brief discussion of some of the limitations of the reinforcement learning framework, highlighting questions for future research.     

Decision-making and associative color learning in harnessed bumblebees (Bombus impatiens)

In honeybees, the conditioning of the proboscis extension response (PER) has provided a powerful tool to explore the mechanisms underlying olfactory learning and memory. Unfortunately, PER conditioning does not work well for visual stimuli in intact honeybees, and performance is improved only after antennal amputation, thus limiting the analysis of visual learning and multimodal integration. Here, we study visual learning using the PER protocol in harnessed bumblebees, which exhibit high levels of odor learning under restrained conditions. We trained bumblebees in a differential task in which two colors differed in their rewarding values. We recorded learning performance as well as response latency and accuracy. Bumblebees rapidly learned the task and discriminated the colors within the first two trials. However, performance varied between combinations of colors and was higher when blue or violet was associated with a high reward. Overall, accuracy and speed were negatively associated, but both components increased during acquisition. We conclude that PER conditioning is a good tool to study visual learning, using Bombus impatiens as a model, opening new possibilities to analyze the proximate mechanisms of visual learning and memory, as well as the process of multimodal integration and decision-making.     

Separating value from selection frequency in rapid reaching biases to visual targets

Stimuli associated with positive rewards in one task often receive preferential processing in a subsequent task, even when those associations are no longer relevant. Here we use a rapid reaching task to investigate these biases. In Experiment 1 we first replicated the learning procedure of Raymond and O'Brien (2009), for a set of arbitrary shapes that varied in value (positive, negative) and probability (20%, 80%). In a subsequent task, participants rapidly reached toward one of two shapes, except now the previously learned associations were irrelevant. As in the previous studies, we found significant reach biases toward shapes previously associated with a high probable, positive outcome. Unexpectedly, we also found a bias toward shapes previously associated with a low probable, negative outcome. Closer inspection of the learning task revealed a potential second factor that might account for these results; since a low probable negative shape was always paired with a high probable negative shape, it was selected with disproportionate frequency. To assess how selection frequency and reward value might both contribute to reaching biases we performed a second experiment. The results of this experiment at a group level replicated the reach-bias toward positively rewarding stimuli, but also revealed a separate bias toward stimuli that had been more frequently selected. At the level of individual participants, we observed a variety of preference profiles, with some participants biased primarily by reward value, others by frequency, and a few actually biased away from both highly rewarding and high frequency targets. These findings highlight that: (1) rapid reaching provides a sensitive readout of preferential processing; (2) target reward value and target selection frequency are separate sources of bias; and (3) group-level analyses in complex decision-making tasks can obscure important and varied individual differences in preference profiles.     

With age comes wisdom: decision making in younger and older adults

In two experiments, younger and older adults performed decision-making tasks in which reward values available were either independent of or dependent on the previous sequence of choices made. The choice-independent task involved learning and exploiting the options that gave the highest rewards on each trial. In this task, the stability of the expected reward for each option was not influenced by the previous choices participants made. The choice-dependent task involved learning how each choice influenced future rewards for two options and making the best decisions based on that knowledge. Younger adults performed better when rewards were independent of choice, whereas older adults performed better when rewards were dependent on choice. These findings suggest a fundamental difference in the way in which younger adults and older adults approach decision-making situations. We discuss the results in the context of prominent decision-making theories and offer possible explanations based on neurobiological and behavioral changes associated with aging.     

Involvement of the rat anterior cingulate cortex in control of instrumental responses guided by reward expectancy

The anterior cingulate cortex (ACC) plays a critical role in stimulus-reinforcement learning and reward-guided selection of actions. Here we conducted a series of experiments to further elucidate the role of the ACC in instrumental behavior involving effort-based decision-making and instrumental learning guided by reward-predictive stimuli. In Experiment 1, rats were trained on a cost-benefit T-maze task in which they could either choose to climb a barrier to obtain a high reward (four pellets) in one arm or a low reward (two pellets) in the other with no barrier present. In line with previous studies, our data reveal that rats with quinolinic acid lesions of the ACC selected the response involving less work and smaller reward. Experiment 2 demonstrates that breaking points of instrumental performance under a progressive ratio schedule were similar in sham-lesioned and ACC-lesioned rats. Thus, lesions of the ACC did not interfere with the effort a rat is willing to expend to obtain a specific reward in this test. In a subsequent task, we examined effort-based decision-making in a lever-press task where rats had the choice between pressing a lever to receive preferred food pellets under a progressive ratio schedule, or free feeding on a less preferred food, i.e. lab chow. Results show that sham- and ACC-lesioned animals had similar breaking points and ingested comparable amounts of less-preferred food. Together, the results of Experiment 1 and 2 suggest that the ACC plays a role in evaluating how much effort to expend for reward; however, the ACC is not necessary in all situations requiring an assessment of costs and benefits. In Experiment 3 we investigated learning and reversal learning of instrumental responses guided by reward predictive stimuli. A reaction time (RT) task demanding conditioned lever release was used in which the upcoming reward magnitude (five vs. one food pellet) was signalled in advance by discriminative visual stimuli. Results revealed that rats with ACC lesions were able to discriminate reward magnitude-predictive stimuli and to adapt instrumental behavior to reversed stimulus-reward magnitude contingencies. Thus, in a simple discrimination task as used here, the ACC appears not to be required to discriminate reward magnitude-predictive stimuli and to use the learned significance of the stimuli to guide instrumental behavior.     

抑郁对社会决策的影响

从社会决策角度出发,依托博弈论的经典范式是研究抑郁症病人人际与社会功能障碍的一个切入点。Ruff和Fehr （2014）提出在社会决策中存在三类情境,即社会反馈、替代性评价、社会原则。我们从这个理论框架出发,发现抑郁症病人在社会反馈加工中存在社会性快感缺失,对社会拒绝的敏感性增强;在替代性评价过程中,共情和心理理论能力减弱;抑郁症病人对决策中的社会原则（公平、合作）存在适应不良现象,如过度利他性。未来的研究一方面可进一步探索抑郁症病人的社会性快感缺失现象,另一方面可采用经颅电/磁刺激与脑成像技术结合或超扫描技术,提高研究结果的解释力和生态效度。