Imagining the future: degraded representations of future rewards and events in schizophrenia

Over the course of life, most people work toward temporally distant rewards such as university degrees or work-related promotions. In contrast, many people with schizophrenia show deficits in behavior oriented toward long-term rewards, although they function adequately when rewards are more immediately present. Moreover, when asked about possible future events, individuals with schizophrenia show foreshortened future time perspectives relative to healthy individuals. Here, we take the view that these deficits are related and can be explained by cognitive deficits. We compared the performance of participants with schizophrenia (n = 39) and healthy participants (n = 25) on tasks measuring reward discounting and future event representations. Consistent with previous research, we found that relative to healthy participants, those with schizophrenia discounted the value of future rewards more steeply. Furthermore, when asked about future events, their responses were biased toward events in the near future, relative to healthy participants' responses. Although discounting and future representations were unrelated in healthy participants, we found significant correlations across the tasks among participants with schizophrenia, as well as correlations with cognitive variables and symptoms. Further analysis showed that statistically controlling working memory eliminated group differences in task performance. Together these results suggest that the motivational deficits characteristic of schizophrenia relate to cognitive deficits affecting the ability to represent and/or evaluate distant outcomes, a finding with important implications for promoting recovery from schizophrenia.     

跨期选择的认知机制与神经基础

跨期选择是指个体对发生在不同时间的成本与收益进行权衡的决策过程。跨期选择的计算模型从经济学的角度用数学模型来建构时间折扣函数,而认知成分模型则从心理学的角度来研究跨期选择中的心理效应与认知成分。跨期选择的神经基础有三种不同的研究取向：双机制加工取向、单机制加工取向、自我控制取向。未来研究应该在跨期选择的认知机制、神经通路及运行机制、跨期选择的应用,以及从进化的角度对人与动物的跨期选择行为进行更深入的研究。     

Not my future? Core values and the neural representation of future events

Individuals with pronounced self-transcendence values have been shown to put greater weight on the long-term consequences of their actions when making decisions. Using functional magnetic resonance imaging, we investigated the neural mechanisms underlying the evaluation of events occurring several decades in the future as well as the role of core values in these processes. Thirty-six participants viewed a series of events, consisting of potential consequences of climate change, which could occur in the near future (around 2030), and thus would be experienced by the participants themselves, or in the far future (around 2080). We observed increased activation in anterior VMPFC (BA11), a region involved in encoding the personal significance of future events, when participants were envisioning far future events, demonstrating for the first time that the role of the VMPFC in future projection extends to the time scale of decades. Importantly, this activation increase was observed only in participants with pronounced self-transcendence values measured by self-report questionnaire, as shown by a statistically significant interaction of temporal distance and value structure. These findings suggest that future projection mechanisms are modulated by self-transcendence values to allow for a more extensive simulation of far future events. Consistent with this, these participants reported similar concern ratings for near and far future events, whereas participants with pronounced self-enhancement values were more concerned about near future events. Our findings provide a neural substrate for the tendency of individuals with pronounced self-transcendence values to consider the long-term consequences of their actions.     

The surprisingly low motivational power of future rewards: Comparing conventional money-based measures of discounting with motivation-based measures

Temporal discount rates are often poor predictors of behaviors that we expect will be motivated by the future. The current research suggests this may be because conventional discounting measures are poor measures of the motivational value of future rewards. In six studies, I develop motivation-based measures of the present value (PV) of future rewards and compare the PVs obtained with those obtained using conventional money-based discounting measures. Conventional money-based PVs consistently overestimate motivation-based PVs and are discriminable from them. I explore explanations for this mismatch, including timing of effort exertion (Study 2) and loss aversion (Study 3), both features of the motivation-based measures. In Study 5, I use self-reports of valuation strategies and a time pressure manipulation to demonstrate that participants use different valuation strategies in the conventional money-based and the motivation-based measures that, in part, determine the difference in PVs obtained and the relatively low correspondence between them.     

Episodic Future Thinking Reduces Delay Discounting of Gains and Losses: The Role of Regulatory Focus1,2

We examined the moderating effect of regulatory foci on the efficacy of episodic future thinking in reducing delay discounting. We hypothesized that the impact of imagining positive future events (vs. recent positive events) on delay discounting of gains would be stronger for individuals with a high promotion focus than for those with a high prevention focus (Hypothesis 1). Conversely, the effects of imagining adverse future events (vs. recent negative events) on delay discounting of losses would be stronger for individuals with a high prevention focus than for those with a high promotion focus (Hypothesis 2). We conducted two experiments in which participants, randomly allocated to episodic future thinking (EFT) or episodic recent thinking (ERT) groups, completed a delayed discounting task of gain (Experiment 1) or loss (Experiment 2). Experiment 1 (N = 73) weakly supported Hypothesis 1; Experiment 2 (N = 99) did not support Hypothesis 2. Our findings suggest positive EFT is particularly effective for individuals with a high promotion focus compared to individuals with a high prevention focus, which further reveals how EFT attenuates delay discounting.     

负折扣现象:跨期决策中的自我-他人决策差异

负折扣现象作为一种违背时间折扣假定的现象越来越多地引起研究者关注。本文通过两种指标考察了为自己决策和为他人决策在负折扣现象上的差异。实验1运用二择一选择范式考察人们在为自己决策和为他人决策时对于何时发生负性事件的时间偏好。结果发现,相比较于为他人决策,为自己决策时被试更倾向于选择早些发生负性事件,即更容易产生负折扣现象。实验2运用测量时间折扣率的经典范式考察了人们在为自己决策和为他人决策时的时间折扣率。结果发现,为自己决策时比为他人决策时的时间折扣率更小,更容易出现负折扣率。总体结果表明,为自己决策比为他人决策更容易出现负折扣现象。从情绪卷入的角度看,我们推测,为自己决策时由于更多的预期负性情绪卷入,从而导致更容易产生负折扣现象。     

Evolutionary economics of mental time travel?

What is the function of our capacity for 'mental time travel'? Evolutionary considerations suggest that vivid memory and imaginative foresight may be crucial cognitive devices for human decision making. Our emotional engagement with past or future events gives them great motivational force, which may counter a natural tendency towards time discounting and impulsive, opportunistic behavior. In this view, whereas simple episodic memory provides us with a store of relevant, case-based information to guide decisions, mental time travel nudges us towards more restrained choices, which in the long term are advantageous, especially so given human dependence on cooperation and coordination.     

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.     

成瘾人群跨期选择的神经机制及干预方法

成瘾可分为物质成瘾和行为成瘾, 两类成瘾人群在跨期选择上都表现出高时间折扣率的缺陷, 但也有各自的特异性特征。成瘾人群跨期选择缺陷的神经基础主要集中在评估网络(腹内侧前额叶、纹状体、后扣带皮层等)、认知控制网络(前额叶皮层、前扣带皮层等)和预期想象网络(海马、杏仁核等); 可利用心理训练来改善成瘾人群跨期选择缺陷, 其干预方法包括工作记忆训练、预期想象训练、金钱管理指导等。未来研究应该从成瘾者跨期选择缺陷的认知机制、3个神经网络系统的交互作用机理、行为遗传学以及开发有效的干预方法等方面展开大量研究。     

Age differences in temporal discounting: the role of dispositional affect and anticipated emotions

We examined age differences in temporal discounting, the tendency to devalue delayed outcomes relative to immediate ones, with particular emphasis on the role of affective responses. A life-span sample completed an incentive-compatible temporal discounting task involving both monetary gains and losses. Covariates included demographic characteristics, cognitive functioning, personality traits, affective responses, and subjective health. Advanced age was associated with a lower tendency to discount the future, but this effect reached statistical significance only for the discounting of delayed gains. An examination of covariates suggested that age effects were associated with age differences in mental health and affective responses rather than demographic or cognitive variables.     

Imagining the near and far future: The role of location familiarity

Plausible personal events envisioned as occurring in the near future tend to be reported as more vivid than those set in the far future. Why is this? The present set of three experiments identified one’s familiarity with the location in which the event is placed as critical in this regard. Specifically, Experiment 1 demonstrated that amongst a wide range of phenomenological characteristics, clarity of location appears to drive the overall difference in vividness between events imagined to take place in the near and the far future. Experiments 2 and 3 were designed to further elucidate this finding. Experiment 2 demonstrated that near future events are more likely than far future events to be imagined in familiar locations. Experiment 3 showed that future events set in familiar locations tend to be imagined with greater clarity than those set in unfamiliar locations. The results of all three experiments converge on the conclusion that the difference in vividness of events imagined as occurring in the near and far future is mediated by one’s familiarity with the location in which the event is imagined to occur.     

情绪对延迟折扣的影响：现状、机制与展望

延迟折扣研究领域日益重视情绪的影响作用。本文基于三类研究取向对情绪与延迟折扣关系研究进行了回顾。情绪效价和唤醒度均影响延迟折扣,但是研究结果并不一致;具体情绪类型不同,其对延迟折扣影响也存在差异。除此之外,本文就情绪信息理论、情绪动机维度理论和评估倾向理论如何解释延迟折扣进行了详细阐述。未来的研究需要进一步深入考察情绪影响延迟折扣的认知神经机制,从而为延迟折扣的负性情绪效应的干预提供可靠的科学依据。     

The neural mechanisms of inter-temporal decision-making: understanding variability

Humans and animals prefer immediate over delayed rewards (delay discounting). This preference for smaller-but-sooner over larger-but-later rewards shows substantial interindividual variability in healthy subjects. Moreover, a strong bias towards immediate reinforcement characterizes many psychiatric conditions such as addiction and attention-deficit hyperactivity disorder. We discuss the neural mechanisms underlying delay discounting and describe how interindividual variability (trait effects) in the neural instantiation of subprocesses of delay discounting (such as reward valuation, cognitive control and prospection) contributes to differences in behaviour. We next discuss different interventions that can partially remedy impulsive decision-making (state effects). Although the precise neural mechanisms underlying many of these modulating influences are only beginning to be unravelled, they point towards novel treatment approaches for disorders of impulse control.     

Processing alternative explanations of behavior: correction or integration?

Three experiments investigated how activation of knowledge about situational forces affects discounting in dispositional inference tasks. Each experiment varied a different knowledge activation factor--salience, accessibility, or specificity of situational information. In addition, all 3 experiments varied situational demands and cognitive load. The results showed that cognitive load eliminated discounting when situational information was low in salience, accessibility, or specificity. However, when situational information was more salient, accessible, or specific, it produced strong discounting effects even when perceivers were under cognitive load. These results are discussed in terms of correction and integration models of dispositional inferences from behavior.     

Preference reversals with losses

People who prefer larger, later gains over smaller, sooner gains when considering outcomes far in the future often reverse their preference as the alternatives become closer in time. This finding, which is contrary to a normative economic account of intertemporal choice, has been interpreted as support for hyperboloid discounting, but the results can also be explained by steeper discounting of smaller amounts. The present study is the first to demonstrate that analogous preference reversals occur with losses: People who preferred a smaller, sooner loss over a larger, later loss when the outcomes were far in the future reversed their preference when these alternatives were closer in time. Because there was no magnitude effect (i.e., smaller losses were not discounted more steeply than larger losses), the present findings strongly support the proposition that reversals in preference between delayed outcomes occur because of the hyperboloid shape of the discounting function.     

Do Measures of Executive Functioning and Manipulation of Ego Depletion Predict How University Students Discount Probabilistic Gains and Losses?

Discounting occurs when the subjective value of an outcome is altered because the outcome is delayed or uncertain. Previous research has suggested that how individuals discount delayed gains is related to executive functioning. The present study attempted to extend this relationship to discounting of probabilistic gains and losses, and to examine whether diminishing cognitive resources would impact how participants discounted monetary outcomes. In Experiment 1, university students completed an executive function measure and then a probability-discounting task that involved the hypothetical sum of either $1,000 or $100,000 framed as either a gain or a loss. The executive function of organization was a significant predictor of how participants discounted all four outcomes while motivational drive predicted discounting of losses, but not gains. In Experiment 2, participants completed the same measures with the addition of an ego-depletion task to deplete cognitive resources before making discounting decisions. The executive function of motivational drive and empathy were significant predictors of how participants discounted both loss outcomes. The results suggest that discounting of monetary outcomes is related to the executive function of organization for gains and motivational drive, and empathy for losses. They also support the notion that the discounting of gains may be a distinct process from the discounting of losses.     

Greater delay discounting among girls,but not boys,with ADHD correlates with cognitive control

Cognitive neuroscience models suggest both reward valuation and cognitive control contribute to reward-based decision-making. The current study examined the relationship between cognitive control and delay discounting (i.e., choosing smaller, immediate over larger, delayed rewards) in a large sample of boys and girls diagnosed with attention-deficit/hyperactivity disorder (ADHD; N = 95) and typically developing control children (TD; N = 59). Specifically, we examined performance on multiple measures of cognitive control (i.e., Go/No-Go task, Stop Signal task, and Spatial Span task) and delay discounting (i.e., Classic Delay Discounting and Real-Time Delay Discounting tasks), as well as the relationship between these measures. Results indicated that sex moderated the effects of group on task performance. Specifically, girls with ADHD, but not boys with the disorder, exhibited atypical delay discounting of real-time rewards. Results from correlational analyses indicated that delay discounting and cognitive control were not significantly correlated in the overall sample. Multiple regression analyses demonstrated that among girls with ADHD poorer spatial working memory and inhibitory control predicted greater real-time discounting. Collectively, findings provide support for distinct patterns of cognitive control and delay discounting among school-aged girls and boys with ADHD. Additionally, findings suggest that among girls with ADHD, those who exhibit relatively poor working memory and inhibitory control might be a particularly vulnerable subgroup with the greatest propensity to exhibit maladaptive decision-making.     

解释水平视角下的乐观偏差效应

研究基于解释水平理论,考查心理距离对乐观偏差效应的影响。实验从心理距离的事件概率维度、时间距离维度、空间距离维度入手,采用自编的材料对677名被试进行测量,探讨心理距离的远近对乐观偏差产生的影响。结果表明,被试对未来生活事件的判断存在总体上的乐观偏差。在较远的心理距离条件下,被试表现出更大的乐观偏差;而在较近的心理距离中,乐观偏差效应明显减小。但在时间距离维度以及消极事件的概率维度上,表现出与总体乐观偏差不一致的现象。     

时间贴现在神经和行为上的年龄特征

时间贴现的年龄发展具有阶段性。前额皮质, 边缘系统和多巴胺能系统的发展成熟是从儿童期到成人期时间贴现发展变化的神经生物基础。成人期到老年期时间贴现年龄特征的研究结果不一致。概率贴现、未来定向、延迟满足等被用来探讨时间贴现年龄发展特征。可以从大脑不同区域的发展轨迹, 延迟时段的心理意义来进一步深入研究。     

Resource slack and propensity to discount delayed investments of time versus money

The authors demonstrate that people discount delayed outcomes as a result of perceived changes over time in supplies of slack. Slack is the perceived surplus of a given resource available to complete a focal task. The present research shows that, in general, people expect slack for time to be greater in the future than in the present. Typically, this expectation of growth of slack in the future is more pronounced for time than for money. In 7 experiments, the authors demonstrate that systematic temporal shifts of perceived slack determine the extent and the pattern of delay discounting, including hyperbolic discounting. They use this framework to explain differential propensity to delay investments and receipts of time and money.