Temporal Discounting Paradigm Research Articles

Striatal bases of temporal discounting in early adolescents

Steeper rates of temporal discounting—the degree to which smaller-sooner (SS) rewards are preferred over larger-later (LL) ones—have been associated with impulsive and ill-advised behaviors in adolescence. Yet, the underlying neural systems remain poorly understood. Here we used a well-established temporal discounting paradigm and functional MRI (fMRI) to examine engagement of the striatum—including the caudate, putamen, and ventral striatum (VS)—in early adolescence (13–15 years; N = 27). Analyses provided evidence of enhanced activity in the caudate and VS during impulsive choice. Exploratory analyses revealed that trait impulsivity was associated with heightened putamen activity during impulsive choices. A more nuanced pattern was evident in the cortex, with the dorsolateral prefrontal cortex mirroring the putamen and posterior parietal cortex showing the reverse association. Taken together, these observations provide an important first glimpse at the distributed neural systems underlying economic choice and trait-like individual differences in impulsivity in the early years of adolescence, setting the stage for prospective-longitudinal and intervention research.

ADHD and the Choice of Small Immediate Over Larger Delayed Rewards: A Comparative Meta-Analysis of Performance on Simple Choice-Delay and Temporal Discounting Paradigms

Objective: Impulsive choices can lead to suboptimal decision making, a tendency which is especially marked in individuals with ADHD. We compared two different paradigms assessing impulsive choice: the simple choice paradigm (SCP) and the temporal discounting paradigm (TDP). Method: Random effects meta-analyses on 37 group comparisons (22 SCP; 15 TDP) consisting of 3.763 participants (53% ADHD). Results: Small-to-medium effect sizes emerged for both paradigms, confirming that participants with ADHD choose small immediate over large delayed rewards more frequently than controls. Moderation analyses show that offering real rewards in the SCP almost doubled the odds ratio for participants with ADHD. Conclusion: We suggest that a stronger than normal aversion toward delay interacts with a demotivating effect of hypothetical rewards, both factors promoting impulsive choice in participants with ADHD. Furthermore, we suggest the SCP as the paradigm of choice due to its larger ecological validity, contextual sensitivity, and reliability.

A spatial discounting test to assess impulsivity in dogs

In domestic dog’s trait impulsivity can be measured psychometrically using the Dog Impulsivity Assessment Scale (DIAS) and experimentally using a temporal discounting paradigm which requires substantial training. A Spatial Discounting Task (SDT) was developed as an alternative experimental method to assess impulsivity, and evaluated performance in adult (2–10 years) and younger (2–9 months) dogs. The test was modified for field use with fewer controls (Simplified Spatial Discounting Task (SDTs)). Convergent validity with the SDT and DIAS Overall Questionnaire Scores (OQS) and stability over time (4–6 weeks) in the two age groups was determined. 96% of dogs recruited reached criterion for testing. A significant positive relationship was found between Maximum Distance Travelled (MDT) in the SDT and OQS in adult dogs (r = 0.46, p = 0.028), with good test-retest reliability evident for both (p < 0.001). In young dogs, there was good test-retest reliability for OQS (p = 0.023), but no significant relationship was found between OQS and MDT, test-retest reliability for MDT in young dogs was poor. In the SDTs, 100% of dogs recruited met criterion for testing and there was a significant relationship between MDT and OQS (r = 0.61, p = 0.027). The SDT appears to be a useful method for measuring impulsivity in adult dogs with wide applicability.

Multiple sclerosis reduces sensitivity to immediate reward during decision making.

Individuals with multiple sclerosis (MS) often face important health-related and financial decisions that involve trade-offs between short-term and long-term benefits, yet decision making is rarely studied in MS patients. The temporal discounting paradigm is a useful tool for investigating such time-dependent choices in humans. Here, we investigated whether patients with relapsing-remitting MS differed from healthy controls when making choices between hypothetical monetary rewards available at different points in time. Participants were tested in two conditions: in one, the choice was between a smaller amount of money available immediately and a larger amount of money available at a later date; in the other, a fixed delay of 60 days was added to both options. We found that, compared with healthy controls, MS patients favored less the sooner reward in the condition involving an immediate reward, whereas no difference between MS patients and the control group emerged in the condition involving only delayed rewards. Moreover, the decreased immediacy bias was corroborated by lower scores at scale that assesses responsiveness to rewards in MS patients. Taken together, these findings indicate reduced sensitivity to immediate reward and a consequent stronger willingness to defer gratification in MS individuals. (PsycINFO Database Record

Stress-Induced Executive Dysfunction in GDNF-Deficient Mice, A Mouse Model of Parkinsonism

Maladaptive reactivity to stress is linked to improper decision making, impulsivity, and discounting of delayed rewards. Chronic unpredictable stress (CUS) alters dopaminergic function, re-shapes dopaminergic circuits in key areas involved in decision making, and impairs prefrontal-cortex dependent response inhibition and working memory. Glial-derived neurotrophic factor (GDNF) is essential for regulating dopamine (DA) release in the basal ganglia and for the survival of dopaminergic neurons; GDNF-deficient mice are considered an animal model for aging-related Parkinsonism. Recently, GDNF expression in the striatum has been linked to resilience to stress. Here we investigated the effects of CUS on decision making in GDNF-heterozygous (HET) mice and their wild-type littermate controls (WT). Before CUS no differences in temporal discounting (TD) were found between genotypes. However, following CUS GDNF HET mice, having a partial reduction of GDNF levels, showed increased impulsive choice indexed by a reduction in percent Larger-Later (LL) choices in the TD paradigm, and a reduction in area under the TD curve. Moreover, stressed GDNF HET mice, but not their WT controls, showed decreased neuronal activation (number of cFos positive neurons) in the orbitofrontal cortex (OFC), nucleus accumbens (NA) core, and NA shell, suggestive of a maladaptive response to stress. Interestingly, area under the TD curve positively correlated with cFos activation in the NA core, and NA shell, but not with orbitofrontal activity. These results provide further evidence of the differential involvement of the OFC, NA core, and NA shell in impulsive choice, and identify GDNF-deficient mice as a double-hit (gene × environment) model of stress-related executive dysfunction, particularly relevant to substance abuse and Parkinson’s disease (PD).

Decision Making after Traumatic Brain Injury: A Temporal Discounting Paradigm

A temporal discounting paradigm was used to examine decision making for hypothetical monetary reward following traumatic brain injury (TBI). A case-control design compared individuals following moderate or severe TBI with a healthy control group matched for age and gender. The impact of intelligence, impulsivity, and mood on temporal discounting performance was examined. A within-subjects design for the TBI group determined the influence of a range of neuropsychological tests on temporal discounting performance. Both patients and controls demonstrated temporal discounting. However, the TBI group discounted more than controls, suggesting that their decision making was more impulsive, consistent with ratings on the impulsiveness questionnaire. Discounting performance was independent of neuropsychological measures of intelligence, memory, and executive function. There was no relationship between temporal discounting and ratings of everyday executive function made by patients' relatives. Low mood did not account for discounting performance. The results of this study suggest that temporal discounting may be a useful neuropsychological paradigm to assess decision making linked to monetary reward following TBI. Performance was relatively independent of intelligence, memory and standard tests of executive ability and may therefore assist when assessing a patient's mental capacity to manage their financial affairs.

The role of empathy in choosing rewards from another's perspective.

As social animals, we regularly act in the interest of others by making decisions on their behalf. These decisions can take the form of choices between smaller short-term rewards and larger long-term rewards, and can be effectively indexed by temporal discounting (TD). In a TD paradigm, a reward loses subjective value with increasing delay presumably because it becomes more difficult to simulate how much the recipient (e.g., future self) will value it. If this is the case, then the value of delayed rewards should be discounted even more steeply when we are choosing for someone whose feelings we do not readily simulate, such as socially distant strangers. Second, the ability to simulate shows individual differences and is indexed by trait empathy. We hypothesized that individuals high in trait empathy will more readily simulate, and hence discount less steeply for distant others, compared to those who are low on trait empathy. To test these predictions, we asked 63 participants from the general population to perform a TD task from the perspectives of close and distant others, as well as their own. People were found to discount less steeply for themselves, and the steepness of TD increased with increasing distance from self. Additionally, individuals who scored high in trait empathy were found to discount less steeply for distant others compared to those who scored low. These findings confirm the role of empathy in determining how we choose rewards for others.

Dissecting the Effects of Disease and Treatment on Impulsivity in Parkinson's Disease

Converging evidence, including observations in patients with Parkinson's disease (PD), suggests that dopamine plays a role in impulsivity. This multi-faceted construct includes considerations of both time and risk; determining how these more specific processes are affected by PD and dopaminergic treatment can inform neurobiological models. We examined the effects of PD and its treatment on temporal discounting and risky decision-making in a cohort of 23 mild-moderate PD patients and 20 healthy participants. Patients completed the Balloon Analogue Risk Task and a temporal discounting paradigm both on and off their usual dopamine replacement therapy. PD patients did not differ from controls in their initial risk-taking on the Balloon Analogue Risk Task, but took progressively more risks across trials when on medication. A subset of patients and controls was tested again, 1.5-3 years later, to explore the effects of disease progression. On follow-up, baseline risk-taking diminished in patients, but the tendency to take increasing risks across trials persisted. Neither disease progression nor its treatment affected the temporal discounting rate. These findings suggest a different neural basis for temporal discounting and risk-taking, and demonstrate that risk-taking can be further decomposed into initial and trial-by-trial effects, with dopamine affecting only the latter.

I want it and I want it now: Using a temporal discounting paradigm to examine predictors of consumer impulsivity

This paper proposes a new model of consumer impulsivity, using type of good, a person's endorsement of materialistic values, and identity deficits as predictors. Traditional decision making and psychological accounts see impulsive behaviour as a general overweighing of short-term gratification (I want that dress now) relative to longer-term concerns, irrespective of consumer good. Our proposal is that consumers' impulsivity (a) differs according to type of good and (b) is linked systematically to a combination of materialistic values and high identity deficits. Beginning with Study 1, three experiments, using a temporal discounting paradigm, show consistently that discount rates are higher for goods that are seen as highly expressive of identity (e.g., clothes) than goods not expressive of identity (e.g., basic body care products). For materialistic consumers, identity deficits predict discount rates for identity-expressive goods (Study 2), and discount rates change for materialistic individuals when their identity deficits are made salient (Study 3). These findings support a conceptualization of consumer impulsivity as identity-seeking behaviour.

Using a temporal discounting paradigm to measure decision-making and impulsivity following traumatic brain injury: A pilot study

Primary objective: This study reports on a pilot study using a temporal discounting paradigm and a standardized impulsivity questionnaire to examine decision-making in a group of brain injured patients and age matched controls.Methods and procedures: Participants were asked to choose between a larger reward available at a specified time in the future and smaller reward available immediately.Outcome and results: Each of the two groups demonstrated temporal discounting; that is, the subjective value of the reward decreased with increasing delay. However, the TBI group discounted more than the controls, suggesting that their decision-making was more impulsive.Conclusion: The results suggest that a temporal discounting paradigm might be a useful method of assessing decision-making after head trauma, especially in cases where capacity to make decisions about financial awards is an issue or in respect of money management generally.

Temporal Discounting When the Choice Is Between Two Delayed Rewards.

The present experiments extend the temporal discounting paradigm from choice between an immediate and a delayed reward to choice between 2 delayed rewards: a smaller amount of money available sooner and a larger amount available later. Across different amounts and delays, the data were consistently well described by a hyperbola-like discounting function, and the degree of discounting decreased systematically as the delay to the sooner reward increased. Three theoretical models (the elimination-by-aspects, present-value comparison, and common-aspect attenuation hypotheses) were evaluated. The best account of the data was provided by the common-aspect attenuation hypothesis, according to which the common aspect of the choice alternatives (i.e., the time until the sooner reward is available) receives less weight in the decision-making process.