Reward Size Research Articles

Unintended reward costs: the effectiveness of customer referral reward programs for innovative products and services

To encourage customers’ referral behavior and expand their customer base, providers of innovative products and services often use customer referral reward programs (CRPs), though not all CRPs deliver on their initial promise. With one field experiment and four online experiments, this research investigates the effectiveness of rewarded referrals for recruiting new customers for more innovative (versus less innovative) offerings and outlines the conditions in which public referral rewards have unintended ramifications and decrease customers’ referral likelihood. In addition to establishing these effects for more innovative offerings, this research identifies some moderating consequences, such that the detrimental effect of referral rewards on referral behavior can be attenuated by not disclosing referral rewards (for recommenders) to referral recipients, increasing the referral reward size, and rewarding both recommenders and referral recipients. These findings have theoretical and managerial implications.

How environmental regularities affect people's information search in probability judgments from experience.

In everyday life, people encounter smaller rewards with higher probability than larger rewards. Do people expect this reward-probability regularity to hold in experimental settings? To answer this question, we tested whether people's behavior in probability judgment tasks is affected by the correlation between reward size and reward probabilities. In Study 1, we asked people to judge reward probabilities under uncertainty. In line with the ecological reward-probability correlation, people assumed that larger rewards were less likely than smaller rewards. In Study 2, we tested the prediction that people's information search and integration depend on the representativeness of the environment. Participants performed an experience-based probability judgment task in which they sampled outcomes from unknown gambles until they felt confident to estimate the probabilities of the gambles' outcomes. We manipulated the reward-probability relationship of the gambles in 3 experimental groups. Rewards and reward probabilities were negatively correlated, positively correlated, or not correlated at all. A negative correlation mimics the ecological reward-probability relationship often present in real life. We analyzed people's search effort and whether they integrated sample-based uncertainty into their judgments. We found that people sampled fewer outcomes in the ecologically representative condition than in the other 2 conditions. However, people did not integrate sample-based uncertainty in their judgments: In all conditions people treated the observed outcomes as representative of the underlying outcome distribution. People's prior beliefs about regularities in environments provides a potential explanation of why people often rely on small sample sizes when making judgments and decisions from experience. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Signaling Incentive and Drive in the Primate Ventral Pallidum for Motivational Control of Goal-Directed Action.

Processing incentive and drive is essential for control of goal-directed behavior. The limbic part of the basal ganglia has been emphasized in these processes, yet the exact neuronal mechanism has remained elusive. In this study, we examined the neuronal activity of the ventral pallidum (VP) and its upstream area, the rostromedial caudate (rmCD), while two male macaque monkeys performed an instrumental lever release task in which a visual cue indicated the forthcoming reward size. We found that the activity of some neurons in VP and rmCD reflected the expected reward size transiently following the cue. Reward size coding appeared earlier and stronger in VP than in rmCD. We also found that the activity in these areas was modulated by the satiation level of monkeys, which also occurred more frequently in VP than in rmCD. The information regarding reward size and satiation level was independently signaled in the neuronal populations of these areas. The data thus highlighted the neuronal coding of key variables for goal-directed behavior in VP. Furthermore, pharmacological inactivation of VP induced more severe deficit of goal-directed behavior than inactivation of rmCD, which was indicated by abnormal error repetition and diminished satiation effect on the performance. These results suggest that VP encodes incentive value and internal drive and plays a pivotal role in the control of motivation to promote goal-directed behavior.SIGNIFICANCE STATEMENT The limbic part of the basal ganglia has been implicated in the motivational control of goal-directed action. Here, we investigated how the ventral pallidum (VP) and the rostromedial caudate (rmCD) encode incentive value and internal drive and control goal-directed behavior. Neuronal recording and subsequent pharmacological inactivation revealed that VP had stronger coding of reward size and satiation level than rmCD. Reward size and satiation level were independently encoded in the neuronal population of these areas. Furthermore, VP inactivation impaired goal-directed behavior more severely than rmCD inactivation. These results highlight the central role of VP in the motivational control of goal-directed action.

Sales-Based Rebate Design

We study rebate mechanisms according to which a monopolist selling a product introduces rebates as function of the volume of buyers. This enables the firm to induce payoff externalities that ordinarily do not exist. The monopoly firm sells an indivisible good to a mass of consumers with uncertain valuations corresponding to two sources of uncertainty: a systemic uncertainty corresponding to the realized quality, and an idiosyncratic uncertainty modeling the diversity of consumers’ tastes. Analyzing the equilibria of the induced global game among the consumers, we show that introducing positive externality via an increasing aggregate reward program reduces the profit. Using variational optimization techniques, we identify several key characteristics of the optimal reward program: the optimal solution is a “full-refund or nothing” policy, fully reimbursing the buyers if the realized quality falls in one of the finitely many refund-eligible intervals. The number of intervals, though finite, grow unboundedly as consumers’ tastes become less diverse and valuations concentrate around the true quality. While finding the optimal reward program is in general an intractable problem, we fully characterize the optimal solution in two important instances: one with constraints on the reward size and the other with bounds on the rate of change of the reward with sales volume. Despite their simple and intuitive structures, the corresponding optimal reward programs asymptotically recover the optimal solution. Our analysis sheds light on the potential role of novel technology-enabled features of crowd-based markets in developing new revenue management strategies.

The Performance Effect of Goal-Based Prosocial Rewards: Does Reward Size Matter?

In recent years the use of performance-contingent prosocial rewards, where employees must give their reward to a charity or a coworker, has become more common. Using a piece-rate incentive structure, prior research shows small dollar prosocial rewards lead to greater performance than small dollar cash rewards, but this effect diminishes when the reward size increases. We extend this research by examining the motivating effect of prosocial reward under a common goal-based incentive structure. Our experiment uses an effort-sensitive task and participants are rewarded for the attainment of a challenging performance goal. We use a 2 by 2 between-subjects design where we manipulate the type of reward for goal attainment (cash vs. prosocial) and the size of the reward (small vs. large). We find that goal-based prosocial rewards result in higher performance than goal-based cash rewards when the reward size is small, but this performance advantage is not observed when the reward size is large. We also find that the affective value individuals attach to goal attainment mediates our results, and that the performance advantage of small goal-based prosocial (vs. cash) rewards is mainly driven by low-performing participants. Implications for theory and practice are discussed.

Encoding of Reward and Decoding Movement from the Frontal Eye Field during Smooth Pursuit Eye Movements.

Expectation of reward potentiates sensorimotor transformations to drive vigorous movements. One of the main challenges in studying reward is to determine how representations of reward interact with the computations that drive behavior. We recorded activity in smooth pursuit neurons in the frontal eye field (FEF) of two male rhesus monkeys while controlling the eye speed by manipulating either reward size or target speed. The neurons encoded the different reward conditions more strongly than the different target speed conditions. This pattern could not be explained by differences in the eye speed, since the eye speed sensitivity of the neurons was also larger for the reward conditions. Pooling the responses by the preferred direction of the neurons attenuated the reward modulation and led to a tighter association between neural activity and behavior. Therefore, a plausible decoder such as the population vector could explain how the FEF both drives behavior and encodes reward beyond behavior.SIGNIFICANCE STATEMENT Motor areas combine sensory and reward information to drive movement. To disambiguate these sources, we manipulated the speed of smooth pursuit eye movements by controlling either the size of the reward or the speed of the visual motion signals. We found that the relationship between activity in frontal eye field and eye kinematics varied: the eye speed sensitivity was larger for the different reward conditions than for the different target speed conditions. Decoders that pooled signals by the preferred direction of the neurons attenuated the reward modulations. These decoders may indicate how reward can be both encoded beyond eye kinematics at the single neuron level and drive movement at the population level.

Discretion for behavioral selection affects development of habit formation after extended training in rats

As training progresses, animals show a transition from goal-dependent behavior to goal-independent behavior (habitual responses). Habit formation is influenced by several factors, including the amount of training and action-outcome contingency. However, it remains unknown whether and how discretion for behavioral selection influences habit formation. To this end, we trained male rats in two types of two-alternative forced-choice task: visual association and nonvisual association tasks. In the first type of task, rats learned the association between reward and a visual cue, the position of which was randomly changed per trial so that rats had to make a judgmental decision about which choice delivered the reward in each trial (discreet judgment group); in the second type of task, the rats learned that a reward was delivered after either choice following task initiation (uncontrolled judgment group). To test the sensitivity to contingency manipulation, the extinction tests were conducted in short- and long-term trained groups, with the result that the overtrained rats in the uncontrolled judgment group, but not the other three groups, showed less sensitivity. To further investigate the reward sensitivity in the long-term trained groups from another perspective, we continuously and periodically altered the reward size for each trial. The rats of the discreet judgment group changed intertrial intervals depending on reward size, while this tendency was weaker in the uncontrolled judgment group. These results suggest that discreet judgment maintained goal-directed rat behavior, whereas uncontrolled judgment led to the development of habit-like behavior.

Effect of e-referral incentive programs on referrer loyalty on social platforms

ABSTRACTE-referral incentive programs are key instruments to carry out relationship marketing on social platforms. This study explores the effect of e-referral incentive programs on customer loyalty and its mechanisms. Two theories, the cognitive dissonance theory and the attention resource theory are adopted in this study, and therefore, referral dissonance and audience size are introduced as a mediator and a context variable separately. The results show that (1) the reward size and reward scheme have a significant interaction effect on customers’ repurchase intention and their re-referral intention; (2) this kind of interaction effect can be mediated by cognitive dissonance; and (3) the effect of referral incentive programs on customer loyalty will be influenced by the audience size. This study also explains how the referral incentive programs influence customer loyalty in social platforms and therefore can serve as a theoretical guidance for enterprises aiming to develop e-referral incentive programs.

Belief state representation in the dopamine system

Learning to predict future outcomes is critical for driving appropriate behaviors. Reinforcement learning (RL) models have successfully accounted for such learning, relying on reward prediction errors (RPEs) signaled by midbrain dopamine neurons. It has been proposed that when sensory data provide only ambiguous information about which state an animal is in, it can predict reward based on a set of probabilities assigned to hypothetical states (called the belief state). Here we examine how dopamine RPEs and subsequent learning are regulated under state uncertainty. Mice are first trained in a task with two potential states defined by different reward amounts. During testing, intermediate-sized rewards are given in rare trials. Dopamine activity is a non-monotonic function of reward size, consistent with RL models operating on belief states. Furthermore, the magnitude of dopamine responses quantitatively predicts changes in behavior. These results establish the critical role of state inference in RL.

Training Rats Using Water Rewards Without Water Restriction.

High-throughput behavioral training of rodents has been a transformative development for systems neuroscience. Water or food restriction is typically required to motivate task engagement. We hypothesized a gap between physiological water need and hedonic water satiety that could be leveraged to train rats for water rewards without water restriction. We show that when Citric Acid (CA) is added to water, female rats drink less, yet consume enough to maintain long term health. With 24 h/day access to a visual task with water rewards, rats with ad lib CA water performed 84% ± 18% as many trials as in the same task under water restriction. In 2-h daily sessions, rats with ad lib CA water performed 68% ± 13% as many trials as under water restriction. Using reward sizes <25 μl, rats with ad lib CA performed 804 ± 285 trials/day in live-in sessions or 364 ± 82 trials/day in limited duration daily sessions. The safety of CA water amendment was previously shown for male rats, and the gap between water need and satiety was similar to what we observed in females. Therefore, it is likely that this method will generalize to male rats, though this remains to be shown. We conclude that at least in some contexts rats can be trained using water rewards without water restriction, benefitting both animal welfare and scientific productivity.

Is Altruism Sensitive to Scope? The Role of Tangibility

Prior work has shown that people appear insensitive to the scope of their altruistic acts and prosocial behavior. While they respond positively when their choices lead to increasing rewards for themselves, people do not change their behavior when the outcomes for others increase. We demonstrate that the scope sensitivity of altruism depends critically on its tangibility, and suggest that this relationship operates through mental accounting. We show that by increasing the level of tangibility, people can become just as sensitive to changes in the size of rewards for others as if they were earning the rewards themselves.

Previous cocaine self-administration disrupts reward expectancy encoding in ventral striatum

The nucleus accumbens core (NAc) is important for integrating and providing information to downstream areas about the timing and value of anticipated reward. Although NAc is one of the first brain regions to be affected by drugs of abuse, we still do not know how neural correlates related to reward expectancy are affected by previous cocaine self-administration. To address this issue, we recorded from single neurons in the NAc of rats that had previously self-administered cocaine or sucrose (control). Neural recordings were then taken while rats performed an odor-guided decision-making task in which we independently manipulated value of expected reward by changing the delay to or size of reward across a series of trial blocks. We found that previous cocaine self-administration made rats more impulsive, biasing choice behavior toward more immediate reward. Further, compared to controls, cocaine-exposed rats showed significantly fewer neurons in the NAc that were responsive during odor cues and reward delivery, and in the reward-responsive neurons that remained, diminished directional and value encoding was observed. Lastly, we found that after cocaine exposure, reward-related firing during longer delays was reduced compared to controls. These results demonstrate that prior cocaine self-administration alters reward-expectancy encoding in NAc, which could contribute to poor decision making observed after chronic cocaine use.

The computational form of craving is a selective multiplication of economic value

Craving is thought to be a specific desire state that biases choice toward the desired object, be it chocolate or drugs. A vast majority of people report having experienced craving of some kind. In its pathological form craving contributes to health outcomes in addiction and obesity. Yet despite its ubiquity and clinical relevance we still lack a basic neurocomputational understanding of craving. Here, using an instantaneous measure of subjective valuation and selective cue exposure, we identify a behavioral signature of a food craving-like state and advance a computational framework for understanding how this state might transform valuation to bias choice. We find desire induced by exposure to a specific high-calorie, high-fat/sugar snack good is expressed in subjects' momentary willingness to pay for this good. This effect is selective but not exclusive to the exposed good; rather, we find it generalizes to nonexposed goods in proportion to their subjective attribute similarity to the exposed ones. A second manipulation of reward size (number of snack units available for purchase) further suggested that a multiplicative gain mechanism supports the transformation of valuation during laboratory craving. These findings help explain how real-world food craving can result in behaviors inconsistent with preferences expressed in the absence of craving and open a path for the computational modeling of craving-like phenomena using a simple and repeatable experimental tool for assessing subjective states in economic terms.

Interplay between cooperation-enhancing mechanisms in evolutionary games with tag-mediated interactions

Cooperation is fundamental for the long-term survival of biological, social, and technological networks. Previously, mechanisms for the enhancement of cooperation, such as network reciprocity, have largely been studied in isolation and with often inconclusive findings. Here, we present an evolutionary, multiagent-based, and spatially explicit computer model to specifically address the interactive interplay between such mechanisms. We systematically investigate the effects of phenotypic diversity, network structure, and rewards on cooperative behavior emerging in a population of reproducing artificial decision makers playing tag-mediated evolutionary games. Cooperative interactions are rewarded such that both the benefits of recipients and costs of donators are affected by the reward size. The reward size is determined by the number of cooperative acts occurring within a given reward time frame. Our computational experiments reveal that small reward frames promote unconditional cooperation in populations with both low and high diversity, whereas large reward frames lead to cycles of conditional and unconditional strategies at high but not at low diversity. Moreover, an interaction between rewards and spatial structure shows that relative to small reward frames, there is a strong difference between the frequency of conditional cooperators populating rewired versus non-rewired networks when the reward frame is large. Notably, in a less diverse population, the total number of defections is comparable across different network topologies, whereas in more diverse environments defections become more frequent in a regularly structured than in a rewired, small-world network of contacts. Acknowledging the importance of such interaction effects in social dilemmas will have inevitable consequences for the future design of cooperation-enhancing protocols in large-scale, distributed, and decentralized systems such as peer-to-peer networks.

A Mechanism Design for Participatory Rural Development Projects: An Application of Game Theory and Saemaul-Undong of Korea

과거 우리나라 농촌개발모형인 새마을운동의 핵심정신인 ‘자조(Self-Help)’를 기반으로 국제개발협력사업에서 협력국 주민들의 자부담을 요구하는 새마을운동형 농촌개발사업은, 최근 다자 및 양자원조 기관들의 관심을 받기 시작하고 있다. UNDP는 최근 연구에서 새마을운동형 농촌개발 사업을 현장에 적용하기 위한 국가 및 지역전략, 협력국가 선정기준, 시행 메커니즘을 제시하였으나, 주민의 참여를 유인하기 위한 구체적이고 정량적 가이드라인은 제시하지 못하고 있다. 본 연구는 逆게임이론(Reverse Game Theory)인 메커니즘 디자인(Mechanism Design)을 이용하여, 경쟁을 통해 주민들에게 참여유인을 제공하는 자부담 수준에 따른 보상수준을 계량화하고 이를 표로 제시함으로써, 사업형성이나 시행단계에서 용이하게 적용할 수 있도록 하였다. 연구결과, 개인합리성과 단체합리성을 만족하여 주민의 자발적 참여를 유인하는 조건들은 1) 주민의 참여를 유인하기 위한 추가적 보상액의 비율은, 공여기관이 부담한 금액에 대한 주민의 총(현물 및 현금)자부담의 상대적 비율과 주민의 현물 자부담의 상대적 비율의 합보다 크게 결정되어야 하며, 2) 수혜자의 현금 및 현물 자부담 비중은 50%를 넘지 않도록 하여야 한다는 것이다. 이러한 조건을 만족하는 보상수준 및 참여도의 조합들은 게임이론의 핵(核; Core)에 해당하며, 이들 가운데 주민들간의 갈등을 최소화하는 조합은 중핵(中核; Nucleolus)으로써, 주민은 현물 또는 현금으로 약 20%의 사업비를 자조(Self-Help) 비용으로 부담하는 것이 바람직하다는 결론에 이르렀다. 이러한 결과는 기 시행되었던 새마을운동 사업에서의 추천 자부담율(20%) 및 실제 자부담율(49%)과 모순되지 않고 있음을 발견하였다.Many rural development projects were unsuccessful due to lack of voluntary participation by recipient villagers. The objectives of this study are: 1) To provide a quantitative guideline on reward level to induce villagers’ participation, 2) To integrate the spirit of Self-Help and a competition process into the incentive mechanism design. It is found that such participatory mechanisms can be devised so that the outcome is in the Core. To achieve the objective, Mechanism Design is used and the derived conditions are: 1) The size of reward has to be greater than the relative size of cash and in-kind contribution to the size of monetary benefit, 2) The contribution ratio from villagers in cash or in-kind should not exceed 50%. A reward assignment table is proposed for easier application of the result in the field, along with recommended participation level of 20% implied by Nucleolus.

Risky Business? Welfare State Reforms and Government Support in Britain and Denmark

Are welfare state reforms electorally dangerous for governments? Political scientists have only recently begun to study this seemingly simple question, and existing work still suffers from two shortcomings. First, it has never tested the reform–vote link with data on actual legislative decisions for enough points in time to allow robust statistical tests. Secondly, it has failed to take into account the many expansionary reforms that have occurred in recent decades. Expansions often happen in the same years as cutbacks. By focusing only on cutbacks, estimates of the effects of reforms on government popularity become biased. This article addresses both shortcomings. The results show that voters punish governments for cutbacks, but also reward them for expansions, making so-called compensation, a viable blame-avoidance strategy. The study also finds that the size of punishments and rewards is roughly the same, suggesting that voters’ well-documented negativity bias does not directly translate into electoral behavior.

Did the financial crisis affect the market valuation of large systemic U.S. banks?

We examine the impact of the financial crisis on the stock market valuation of large and systemic U.S. bank holding companies (BHCs). Using the Bertsatos and Sakellaris (2016) model of fundamental valuation of bank equity, we provide evidence that the financial crisis has not altered investors’ attitudes towards bank characteristics. In particular, before, during, and after the crisis, investors in large and systemic U.S. BHCs seemed to penalize leverage, albeit temporarily. Both before and after the crisis, they reward size in the short run. This pattern is appearing only briefly during the crisis. We also show that bank opacity plays no role in market valuation either in the short run or in the long run. Last but not least, we find evidence that stress testing has been informative to the market and that those BHCs that failed at the post-crisis stress tests were not subsequently valued differently by the market.

The rat retrosplenial cortex as a link for frontal functions: A lesion analysis

Cohorts of rats with excitotoxic retrosplenial cortex lesions were tested on four behavioural tasks sensitive to dysfunctions in prelimbic cortex, anterior cingulate cortex, or both. In this way the study tested whether retrosplenial cortex has nonspatial functions that reflect its anatomical interactions with these frontal cortical areas. In Experiment 1, retrosplenial cortex lesions had no apparent effect on a set-shifting digging task that taxed intradimensional and extradimensional attention, as well as reversal learning. Likewise, retrosplenial cortex lesions did not impair a strategy shift task in an automated chamber, which involved switching from visual-based to response-based discriminations and, again, included a reversal (Experiment 2). Indeed, there was evidence that the retrosplenial lesions aided the initial switch to response-based selection. No lesion deficit was found on an automated cost-benefit task that pitted size of reward against effort to achieve that reward (Experiment 3). Finally, while retrosplenial cortex lesions affected matching-to-place task in a T-maze, the profile of deficits differed from that associated with prelimbic cortex damage (Experiment 4). When the task was switched to a nonmatching design, retrosplenial cortex lesions had no apparent effect on performance. The results from the four experiments show that many frontal tasks do not require the retrosplenial cortex, highlighting the specificity of their functional interactions. The results show how retrosplenial cortex lesions spare those learning tasks in which there is no mismatch between the internal and external representations used to guide behavioural choice. In addition, these experiments further highlight the importance of the retrosplenial cortex in solving tasks with a spatial component.

Patients with major depressive disorder exhibit reduced reward size coding in the striatum

BackgroundAnhedonia is a core symptom of major depressive disorder (MDD). While recent evidence suggests that reduced motivation for reward may be a core feature of anhedonia, the abnormalities in modulatory neural responses to variable reward amounts in MDD patients remain unclear. We investigated whether MDD patients' ability to represent variable-sized monetary rewards in the striatum is disrupted. MethodsTwelve MDD patients and 12 healthy volunteers completed an assessment of psychometric status and participated in a functional magnetic resonance imaging (fMRI) task that involved the anticipation of financial reward (monetary incentive delay task). The size of the monetary reward was varied among trial conditions and was cued with geometric stimuli. Patients participated in additional fMRI sessions after a 6-week pharmacological treatment with escitalopram, an SSRI. ResultsIn healthy volunteers, striatal activity increased in proportion to the size of the monetary reward during reward anticipation. This pattern was altered in MDD patients, and significant group-by-reward size interaction effects were observed in the bilateral putamen and the left ventral striatum. Reward sensitivity in motor response and striatum activity at three regions were correlated in healthy controls. In MDD patients, this neurobehavioral coupling was not observed. In addition, changes in the neural reward sensitivity parameter at the left ventral striatum in response to treatment were positively correlated with a reduction of depressive symptoms. ConclusionsPatients with MDD exhibit reduced ability to modulate neural response when adjusting for variable amount of reward. This result suggests that reward size coding in the striatum may represent a neural correlate of motivational anhedonia in MDD patients.

Prior Cocaine Self-Administration Increases Response-Outcome Encoding That Is Divorced from Actions Selected in Dorsal Lateral Striatum.

Dorsal lateral striatum (DLS) is a highly associative structure that encodes relationships among environmental stimuli, behavioral responses, and predicted outcomes. DLS is known to be disrupted after chronic drug abuse; however, it remains unclear what neural signals in DLS are altered. Current theory suggests that drug use enhances stimulus-response processing at the expense of response-outcome encoding, but this has mostly been tested in simple behavioral tasks. Here, we investigated what neural correlates in DLS are affected by previous cocaine exposure as rats performed a complex reward-guided decision-making task in which predicted reward value was independently manipulated by changing the delay to or size of reward associated with a response direction across a series of trial blocks. After cocaine self-administration, rats exhibited stronger biases toward higher-value reward and firing in DLS more strongly represented action-outcome contingencies independent from actions subsequently taken rather than outcomes predicted by selected actions (chosen-outcome contingencies) and associations between stimuli and actions (stimulus-response contingencies). These results suggest that cocaine self-administration strengthens action-outcome encoding in rats (as opposed to chosen-outcome or stimulus-response encoding), which abnormally biases behavior toward valued reward when there is a choice between two options during reward-guided decision-making.SIGNIFICANCE STATEMENT Current theories suggest that the impaired decision-making observed in individuals who chronically abuse drugs reflects a decrease in goal-directed behaviors and an increase in habitual behaviors governed by neural representations of response-outcome (R-O) and stimulus-response associations, respectively. We examined the impact that prior cocaine self-administration had on firing in dorsal lateral striatum (DLS), a brain area known to be involved in habit formation and affected by drugs of abuse, during performance of a complex reward-guided decision-making task. Surprisingly, we found that previous cocaine exposure enhanced R-O associations in DLS. This suggests that there may be more complex consequences of drug abuse than current theories have explored, especially when examining brain and behavior in the context of a complex two-choice decision-making task.