情景预见对跨期决策的影响机制

为了探究情景预见对跨期决策的影响机制, 研究采用延迟折扣任务范式, 检验了在情景预见对跨期决策的影响中延迟时间知觉起到的中介作用。两个实验分别操纵了情景预见中未来事件与自我有关的信息和未来事件的情绪特征, 结果均发现情景预见通过改变个体对延迟等待时间的时距知觉影响了跨期决策。想象与自己、与母亲有关的未来事件, 想象积极、中性情绪效价的未来事件都使得被试将延迟等待时间知觉为较短的时间段, 更倾向于选择延迟奖励。想象消极情绪效价的未来事件使得被试将延迟等待时间知觉为较长的时间段, 更加偏好即时奖励。本研究有助于增进人们对情景预见影响跨期决策现象的理解。     

不确定性容忍度对跨期选择的影响及其情景依赖性

采用2(不确定性容忍度：高、低)×2(跨期日期：今天/14天、今天/180天)×2(延迟奖赏值：200元、1000元)混合实验设计,探讨不同任务特征下不确定性容忍度对跨期选择的影响。结果表明：跨期日期为180天时,不确定性容忍度主效应边缘显著;不确定性容忍度与延迟奖赏值交互作用显著：在200元时低容忍度个体对延迟奖赏的折扣程度大于高容忍度个体,在1000元时无此效应;跨期日期为14天时,不确定性容忍度的主效应及其与延迟奖赏值交互作用均不显著。这表明,不确定性容忍度对跨期选择存在影响,但这种影响受到跨期日期和延迟奖赏值的调节,具有情景依赖性。     

更优更耐心：质量结果对跨期选择的影响

跨期选择以往的研究集中于金钱数量结果。基于维度加工的模型,本文探究了在跨期选择中,人们面对质量差异的结果(如,今天的低配版手机还是六个月后的高配版手机)vs.相对应的金钱结果(如,今天的5000元还是六个月后的6000元)的选择偏好差异。3个实验结果表明：人们面对质量结果(相比于金钱结果)的跨期选择表现得更耐心,而这种现象是由于人们面对选择时在结果维度差异感知不同所致。与金钱结果跨期选择相同,质量结果跨期选择的心理加工过程同样遵循维度间差异比较。本研究为基于维度的跨期选择模型提供了新的证据。     

Good or Bad,We Want it Now: Fixed‐cost Present Bias for Gains and Losses Explains Magnitude Asymmetries in Intertemporal Choice

Intertemporal tradeoffs are ubiquitous in decision making, yet preferences for current versus future losses are rarely explored in empirical research. Whereas rational‐economic theory posits that neither outcome sign (gains vs. losses) nor outcome magnitude (small vs. large) should affect delay discount rates, both do, and moreover, they interact: in three studies, we show that whereas large gains are discounted less than small gains, large losses are discounted more than small losses. This interaction can be understood through a reconceptualization of fixed‐cost present bias, which has traditionally described a psychological preference for immediate rewards. First, our results establish present bias for losses—a psychological preference to have losses over with now. Present bias thus predicts increased discounting of future gains but decreased (or even negative) discounting of future losses. Second, because present bias preferences do not scale with the magnitude of possible gains or losses, they play a larger role, relative to other motivations for discounting, for small magnitude intertemporal decisions than for large magnitude intertemporal decisions. Present bias thus predicts less discounting of large gains than small gains but more discounting of large losses than small losses. The present research is the first to demonstrate that the effect of outcome magnitude on discount rates may be opposite for gains and losses and also the first to offer a theory (an extension of present bias) and process data to explain this interaction. The results suggest that policy efforts to encourage future‐oriented choices should frame outcomes as large gains or small losses. Copyright © 2012 John Wiley & Sons, Ltd.     

Age‐related differences in delay discounting: Immediate reward,reward magnitude,and social influence

Delay discounting refers to the tendency of individuals to subjectively devalue rewards that are to be received in the future, with high rates of delay discounting being associated with a variety of maladaptive life outcomes (e.g., unhealthy dietary and exercise behaviors). The current study explored the psychological and social processes involved in adult age‐related differences in delay discounting of monetary rewards. Younger adults exhibited higher levels of delay discounting than older adults. This increased level of patience in older adults was found whether smaller‐sooner rewards were to be received immediately or in the future. However, there was an interaction with reward magnitude, whereby younger adults exhibited higher levels of delay discounting for smaller reward magnitudes but not larger reward magnitudes. Social influence on delay discounting was investigated by having participants complete three phases of the delay‐discounting task: an individual precollaboration phase, a collaboration phase in age‐group‐matched dyads, and an individual postcollaboration phase. A convergence effect was observed in that dyad members' postcollaboration choices were significantly more similar compared to their baseline choices during the precollaboration phase. Moreover, levels of convergence were comparable between younger and older adults, suggesting age invariance in social influence on delay discounting. The current results demonstrate a degree of malleability in delay discounting that extends into older adulthood, making interventions targeting the construct a promising avenue for future research.     

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。     

Future anhedonia and time discounting

The temporal location of an event influences the way people mentally represent that event. We suggest (a) that such representational differences can produce an affective forecasting error that we call future anhedonia, which is the belief that hedonic states will be less intense in the future than in the present, and (b) that future anhedonia plays a role in time discounting (i.e., the tendency to place a smaller present value on present events than on future events). Experiments 1a and 1b demonstrated that people are prone to future anhedonia, Experiments 2a and 2b ruled out artifactual alternatives, and Experiments 3a and 3b demonstrated that future anhedonia plays a role in time discounting. These studies suggest that one reason why people prefer to enjoy benefits in the present and pay costs in the future is that they do not realize how they will feel when those costs and benefits are actually experienced.     

Effects of mindful eating training on delay and probability discounting for food and money in obese and healthy-weight individuals

Obese individuals tend to behave more impulsively than healthy weight individuals across a variety of measures, but it is unclear whether this pattern can be altered. The present study examined the effects of a mindful eating behavioral strategy on impulsive and risky choice patterns for hypothetical food and money. In Experiment 1, 304 participants completed computerized delay and probability discounting tasks for food-related and monetary outcomes. High percent body fat (PBF) predicted more impulsive choice for food, but not small-value money, replicating previous work. In Experiment 2, 102 randomly selected participants from Experiment 1 were assigned to participate in a 50-min workshop on mindful eating or to watch an educational video. They then completed the discounting tasks again. Participants who completed the mindful eating session showed more self-controlled and less risk-averse discounting patterns for food compared to baseline; those in the control condition discounted similarly to baseline rates. There were no changes in discounting for money for either group, suggesting stimulus specificity for food for the mindful eating condition.     

情绪对跨期决策的影响：来自单维占优模型的解释

跨期决策的研究表明, 积极情绪和消极情绪状态下的跨期决策行为存在显著差异。本研究从单维占优模型的角度, 揭示情绪影响跨期决策的过程机制。实验1通过诱发被试的积极和消极情绪, 发现积极情绪下被试的时间折扣率更低, 有更强的选择延迟选项的倾向。实验2运用“模拟天平任务”测量了跨期决策时的维度间差异比较, 检验单维占优模型对情绪影响跨期决策的解释性。结果发现, 维度间差异比较在情绪对跨期决策的影响中起中介作用。实验3a和实验3b分别运用时间和金钱启动策略操纵维度间差异比较过程, 再次验证单维占优模型的解释作用。 结果发现, 情绪对跨期决策的效应随着时间和金钱的启动而消失, 进一步支持了维度间差异比较的中介作用。本研究从决策过程的角度, 揭示了情绪影响跨期决策的心理机制, 并进一步为单维占优模型对跨期决策行为的解释性增加了支持性证据。     

Within-subject comparison of real and hypothetical money rewards in delay discounting

A within-subject design, using human participants, compared delay discounting functions for real and hypothetical money rewards. Both real and hypothetical rewards were studied across a range that included $10 to $250. For 5 of the 6 participants, no systematic difference in discount rate was observed in response to real and hypothetical choices, suggesting that hypothetical rewards may often serve as a valid proxy for real rewards in delay discounting research. By measuring discounting at an unprecedented range of real rewards, this study has also systematically replicated the robust finding in human delay discounting research that discount rates decrease with increasing magnitude of reward. A hyperbolic decay model described the data better than an exponential model.     

Culture,psychological proximity to the past and future,and self-continuity

The present research explores how culture influences individuals’ psychological proximity to the past and future, which may predict differences in perceived self-continuity across time. In Studies 1 and 2, we hypothesized and found that Chinese participants saw the past and future as more connected and subjectively closer to the present compared to Euro-Canadians. Following this, we expected and found in Studies 3 and 4 that Chinese participants perceived greater self-continuity over time than Euro-Canadians. Additionally, perceived closeness to the past mediated the effect of culture on past–present self-continuity, which subsequently predicted present–future self-continuity. Study 5 further documented a causal effect of perceived distance to the past on self-continuity. These results suggest that cultural differences in temporal attention to the past and future play a pivotal role in people's sense of self-continuity across time. This has important implications for temporal focalism, intertemporal discounting, and social interactions between Chinese and Euro-Canadians.     

时间洞察力对跨期选择偏好的预测

利用津巴多时间洞察力问卷,采用跨期选择经典范式,考察“现在享乐型”和“未来定向型”两类时间洞察力个体在跨期选择上的偏好,从人格特质角度来探究跨期选择的认知机制。结果发现：(1)现在享乐定向组的延迟折扣率显著高于未来定向组;(2)未来定向组在时间洞察力量表“未来维度”得分与延迟折扣率显著负相关。这说明时间洞察力对个体延迟折扣率具有预测作用,支持了跨期选择的时间感知基础模型。     

Delay discounting of different outcomes: Review and theory

Steep delay discounting is characterized by a preference for small immediate outcomes relative to larger delayed outcomes and is predictive of drug abuse, risky sexual behaviors, and other maladaptive behaviors. Nancy M. Petry was a pioneer in delay discounting research who demonstrated that people discount delayed monetary gains less steeply than they discount substances with abuse liability. Subsequent research found steep discounting for not only drugs, but other nonmonetary outcomes such as food, sex, and health. In this systematic review, we evaluate the hypotheses proposed to explain differences in discounting as a function of the type of outcome and explore the trait- and state-like nature of delay discounting. We found overwhelming evidence for the state-like quality of delay discounting: Consistent with Petry and others' work, nonmonetary outcomes are discounted more steeply than monetary outcomes. We propose two hypotheses that together may account for this effect: Decreasing Future Preference and Decreasing Future Worth. We also found clear evidence that delay discounting has trait-like qualities: People who steeply discount monetary outcomes steeply discount nonmonetary outcomes as well. The implication is that changing delay discounting for one outcome could change discounting for other outcomes.     

Examining children's ability to delay reward: Is the delay discounting task a suitable measure?

Discounting the value of delayed rewards has primarily been measured in children with the delay of gratification task and in adolescents and adults with the delay discounting task. In the present study, we assessed the suitability of the delay discounting task as a measure of temporal discounting in children. A sample of 7- to 9-year-olds (N = 98) completed a delay discounting task, a delay of gratification task, a sensation seeking measure, and IQ measures. In addition, teacher-based assessments of attention-deficit/hyperactivity disorder traits were measured. The results indicated that the majority of children produced meaningful data on the discounting task and discounted rewards hyperbolically. Children with an elevated risk of attention-deficit/hyperactivity disorder showed a trend towards discounting future rewards on the delay discounting task more steeply than did those at low risk. However, delay discounting was unrelated to either delay of gratification or sensation seeking. We interpret these results as providing some support for the use of delay discounting as a measure of intertemporal choice in children, although the results also suggest that delay discounting and delay of gratification tasks may tap different processes in this population.     

Degree of Delay Discounting as a Function of Who Receives the Outcome and the Discounter’s Perceived Level of Social Support

Delay discounting occurs when the subjective value of an outcome decreases as its delivery is delayed. The present study investigated whether how individuals discount delayed outcomes would vary as a function of who would hypothetically experience the outcome and the participants’ perceived level of social support. In Experiment One, 600 university students completed a measure of perceived social support and a discounting task involving four different outcomes, with different groups differing in terms of who would hypothetically receive the outcome being discounted (themselves, their mother, or a classmate). The degree of discounting did not vary as a function of recipient of the outcome, but did vary significantly and inversely with perceived level of social support. Experiment Two replicated the effect of perceived social support in 488 university students, but failed to demonstrate that the degree of discounting varied as a function of the level of social support available to the recipient of the outcome being discounted. These results suggest that people discount outcomes similarly regardless of who will be the recipient of the outcome, but that rates of discounting are reliably altered by the discounter’s own perceived level of social support. The latter finding is potentially informative as to why social-support groups may be valuable in therapeutic environments.     

Discounting of food,sex, and money

Discounting is a useful framework for understanding choice involving a range of delayed and probabilistic outcomes (e.g., money, food, drugs), but relatively few studies have examined how people discount other commodities (e.g., entertainment, sex). Using a novel discounting task, where the length of a line represented the value of an outcome and was adjusted using a staircase procedure, we replicated previous findings showing that individuals discount delayed and probabilistic outcomes in a manner well described by a hyperbola-like function. In addition, we found strong positive correlations between discounting rates of delayed, but not probabilistic, outcomes. This suggests that discounting of delayed outcomes may be relatively predictable across outcome types but that discounting of probabilistic outcomes may depend more on specific contexts. The generality of delay discounting and potential context dependence of probability discounting may provide important information regarding factors contributing to choice behavior.     

Reinforcer pathology II: Reward magnitude,reward delay,and demand for alcohol collectively relate to college students' alcohol related problems

The reinforcer pathologies model of addiction posits that two characteristic patterns of operant behavior characterize addiction. Specifically, individuals suffering from addiction have elevated levels of behavioral economic demand for their substances of abuse and have an elevated tendency to devalue delayed rewards (reflected in high delay discounting rates). Prior research has demonstrated that these behavioral economic markers are significant predictors of many of college students' alcohol-related problems. Delay discounting, however, is a complex behavioral performance likely undergirded by multiple behavioral processes. Emerging analytical approaches have isolated the role of participants' sensitivity to changes in reinforcer magnitude and changes in reinforcer delay. The current study uses these analytic approaches to compare participants' discounting of money versus alcohol, and to build regression models that leverage these new insights to predict a wider range of college students' alcohol related problems. Using these techniques, we were able to 1) demonstrate that individuals differed in their sensitivity to magnitudes of alcohol versus money, but not sensitivity to delays to those commodities and 2) that we could use our behavioral economic measures to predict a range of students' alcohol related problems.     

Changes in intertemporal choices in deviant behaviors

Delay discounting is the process of devaluing results that happen in the future. We present a comprehensive literature review of changes on intertemporal choices in deviant behaviors, namely in (a) substance-related and addictive disorders, (b) disruptive, impulse-control, and conduct disorders, and (c) eating disorders. We also present studies focused on differences in demographic characteristics of the populations by gender, age, and education/social class. Delay discounting is presented as a process of studying intertemporal choices, resulting from decades of empirical research. Studies indicate that this process may provide explanation as to why individuals will sometimes choose a smaller reward, available sooner, instead of a larger reward available later. When studying populations with the above-mentioned problems, they tend to exhibit more pronounced discounting functions than control groups. The association between discounting and gender is not clear. The relationship between delay discounting and age is relatively clear, where older individuals discount less markedly than younger individuals. Studies suggest that shallower discounting gradients are associated with higher levels of intelligence and academic success. We emphasize the need for more empirical research on delay discounting, especially in regard to deviant behavior that may be associated with impulse-control disorders.     

Smokers discount their drug of abuse in the same way as other consumable rewards

Recent research shows that drug abusers discount delayed monetary rewards more than nonabusers do, and they discount delayed substances of abuse (e.g., drugs) more than delayed money. Furthermore, non-drug-abusers discount food and substances of abuse (e.g., alcohol), more than money. Here, we compare the delay and probability discounting of money with that of a directly consumable reward (chocolate) and with that of a substance of abuse (cigarettes), in a drug-using population (smokers). In line with previous research, we found in two experiments that delay discounting differentiated between smokers and nonsmokers, and between money and a nonabused directly consumable reward (chocolate). In addition, our results show that there appears to be no difference in the extent to which smokers discount their abused substance compared to another directly consumable reward. These findings support the contention that drugs and food are part of the same category of primary reinforcers, whereas money is discounted differently, as a conditioned reinforcer.