Prior Reinforcement Research Articles

Reward learning capacity in a community sample of individuals who use cannabis.

Cannabis use has been linked to deficient reward processing; however, little is known about its relation to the specific construct of reward learning, in which behavior is modified through associating novel stimuli with a positive outcome. The probabilistic reward task was used to objectively evaluate reward learning in 38 individuals who use recreational cannabis and 34 control comparison participants from the community. Reward learning was evidenced by the development of a response bias, which indicates the propensity to modulate behavior as a function of prior reinforcement. Both cannabis and control groups demonstrated reward learning, with no group differences in response bias development. Among cannabis participants, trending significant relationships between greater chronicity, r(36) = -.30, p = .077, self-reported potency, r(19) = -.33, p = .052, and poorer reward learning were found. Nonsignificant relationships were found between reward learning and frequency, age of initiation, weekly quantity or Cannabis Use Disorder Identification Test-Revised (CUDIT-R) scores (all p > .05). The ability to form noncannabis reward associations is promising for the success of therapeutic interventions for problematic cannabis use; however, indications of severity of use in relation to poorer reward learning suggests a need for a better pharmacological and pharmacokinetic understanding of cannabis. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

42 Behavioral Correlates of Action-Control in Children with Attention-Deficit/Hyperactivity Disorder

Objective:Children with attention/deficit-hyperactivity disorder (ADHD) exhibit motivational and cognitive impairments that affect daily life functioning. These impairments may reflect a deficit in action-control; the process by which voluntary actions are selected and executed based on prior reinforcement learning. It consists of parallel opposing processes; goal-direction and habit formation. Using the outcome-devaluation paradigm, we previously showed that children with ADHD rely on reflexive habitual, at the expense of goal-directed, behavior to deploy their actions. The current study investigates action-control using a contingency degradation paradigm, which involves outcome overvaluation as opposed to outcome devaluation. We hypothesize that children with ADHD will display a habitual behavior, while healthy controls (HC) will use goal-directed behavior to control their actions.Participants and Methods:We tested 19 ADHD and 14 HC participants (age 6-10 years) for this study. Children with ADHD were recruited from Children’s Specialized Hospital and underwent a structured clinical diagnosis. All participants were screened for ADHD and other neurologic or psychiatric conditions that could contribute to attention impairment using the SNAP-IV rating scale. Participants completed a set of the Woodcock-Johnson® IV assessments. They were tested using an outcome-overvaluation computer-based task. During learning, participants acquired stimulus-reward associations in the acquisition phase, as well as the overvaluation phase. In the latter, one of the rewards was delivered in a similar contingency to the acquisition phase (valued), while the other reward was randomly accompanied by an extra reward in 10% of the trials (overvalued). After the overvaluation phase, participants were presented with two stimuli (associated with a valued, and an overvalued outcome) and were asked to choose one stimulus in extinction. Choosing the overvalued at a higher rate was assigned as goal-directed behavior, while choosing both stimuli at the same rate was assigned as habitual behavior.Results:Independent-samples t-test showed that children with ADHD scored significantly higher than HC in the following measures: ADHD_inattention, ADHD_hyperactive/Impulsive, ADHD_combined, inattention/overactivity, Conner’s index, inattention domain, hyperactive/impulsive domain, and general anxiety disorder screening (P-value for all is <0.001). Results from the computer-based task showed that both groups acquired action-outcome associations during the first two phases of the task. During the extinction phase, HC, as compared to ADHD, responded at a higher rate on the stimuli that were associated with the overvalued outcome (t(31)=2.1, p=0.043); indicating higher tendency to show goal-directed behavior. Further, paired-samples t-test showed that there was no significant difference between response rate on the valued vs. overvalued stimuli in the ADHD group (t(18)=1.027, p=0.318), while there was a difference trending towards significance in response rate in the HC group (t(13)=-2.00, p=0.067). These results show that ADHD responded habitually, while HC responses were goal-directed.Conclusions:Our results indicate that children with ADHD are less likely than HC to engage in goal-directed behavior as opposed to habitual responding. This is consistent with our previous research highlighting a deficit in action-control in ADHD.

Electrophysiological Markers of Aberrant Cue-Specific Exploration in Hazardous Drinkers.

Hazardous drinking is associated with maladaptive alcohol-related decision-making. Existing studies have often focused on how participants learn to exploit familiar cues based on prior reinforcement, but little is known about the mechanisms that drive hazardous drinkers to explore novel alcohol cues when their value is not known. We investigated exploration of novel alcohol and non-alcohol cues in hazardous drinkers (N = 27) and control participants (N = 26) during electroencephalography (EEG). A normative computational model with two free parameters was fit to estimate participants' weighting of the future value of exploration and immediate value of exploitation. Hazardous drinkers demonstrated increased exploration of novel alcohol cues, and conversely, increased probability of exploiting familiar alternatives instead of exploring novel non-alcohol cues. The motivation to explore novel alcohol stimuli in hazardous drinkers was driven by an elevated relative future valuation of uncertain alcohol cues. P3a predicted more exploratory decision policies driven by an enhanced relative future valuation of novel alcohol cues. P3b did not predict choice behavior, but computational parameter estimates suggested that hazardous drinkers with enhanced P3b to alcohol cues were likely to learn to exploit their immediate expected value. Hazardous drinkers did not display atypical choice behavior, different P3a/P3b amplitudes, or computational estimates to novel non-alcohol cues-diverging from previous studies in addiction showing atypical generalized explore-exploit decisions with non-drug-related cues. These findings reveal that cue-specific neural computations may drive aberrant alcohol-related decision-making in hazardous drinkers-highlighting the importance of drug-relevant cues in studies of decision-making in addiction.

Momentary gustative-olfactory sensitivity and tonic heart rate variability are independently associated with motivational behavior

Deficits in motivational functioning including impairments in reward learning or reward sensitivity are common in psychiatric disorders characterized by anhedonia. Recently, anhedonic symptoms have been exacerbated by the pandemic caused by the Coronavirus disease 2019 (COVID-19) in the general population. The present study examined the putative associations between loss of smell (anosmia) and taste (ageusia) sensitivity, irrespective of COVID-19 infection, and anhedonia, measured by a signal-detection task probing the ability to modify behavior as a function of rewards (Probabilistic Reward Task; PRT). Tonic heart rate variability (HRV) was included in the model, due to its association with both smell and taste sensitivity as well as motivational functioning. The sample included 114 healthy individuals (81 females; mean age 22.2 years), who underwent a laboratory session in which dispositional traits, resting HRV and PRT performance were assessed, followed by a 4-days ecological momentary assessment to obtain daily measures of anosmia and ageusia. Lower levels of tonic HRV and lower momentary levels of smell and taste sensitivity were associated with impaired reward responsiveness and ability to shape future behavioral choices based on prior reinforcement experiences. Overall, the current results provide initial correlational evidence that could be fruitfully used to inform future experimental investigations aimed at elucidating the disruptive worldwide mental health consequences triggered by the pandemic.

Optogenetic stimulation of infralimbic cortex projections to the paraventricular thalamus attenuates context-induced renewal.

Contexts associated with prior reinforcement can renew extinguished conditioned responding. The prelimbic (PL) and infralimbic (IL) cortices are thought to mediate the expression and suppression of conditioned responding, respectively. Evidence suggests that PL inputs to the paraventricular nucleus of the thalamus (PVT) drive the expression of cue-induced reinstatement of drug seeking and that IL inputs to the PVT mediate fear extinction retrieval. However, the role of these projections in renewal of appetitive Pavlovian conditioned responding is unknown. We trained male and female Long-Evans rats to associate a conditioned stimulus (CS; 10s white noise) with delivery of a 10% sucrose unconditioned stimulus (US; .2ml/CS) to a fluid port in a distinct context (Context A). We then extinguished responding by presenting the CS without the US in a different context (Context B). At test, rats were returned to Context A, and optogenetic stimulation was delivered to either the IL-to-PVT or PL-to-PVT pathway during CS presentations. Optically stimulating the IL-to-PVT, but not the PL-to-PVT pathway, attenuated ABA renewal of CS port entries, and this effect was similar in males and females. Further, rats self-administered optical stimulation of the IL-to-PVT but not the PL-to-PVT pathway suggesting that activation of the IL-to-PVT pathway is reinforcing. The effectiveness of optical stimulation parameters to activate neurons in the IL, PL and PVT was confirmed using Fos immunohistochemistry. These findings provide evidence for novel neural mechanisms in renewal of responding to a sucrose-predictive CS, as well as more generally in contextual processing and appetitive associative learning.

Decreasing the number of authorization denials in an academic medical oncology practice.

212 Background: Prior authorizations in medical oncology generate additional work and subsequent stress to providers, contributing to physician burnout. Denials of payments can also impact patient care and lead to loss of revenue for the institution. In 2018, first pass denial rates averaged 8.41% per month at our institution. Imaging/scans denials created the majority of this additional work for providers. We aimed to decrease the monthly first pass denial rate average of oncology scans by 25% by May 31, 2020. Methods: Following the creation of a process map of the current prior authorization process and a cause and effect diagram, we identified many factors that could not be controlled (i.e. Insurance company policies). We subsequently created a priority/pay-off-matrix using factors that we could control. Introducing standardized order template for oncology scans was identified as a high impact and feasible countermeasure. Plan-do-study-act cycles (PDSA) plan was developed using this countermeasure to achieve our aim. PDSA 1 included creating template for order entry, educating the nurse partners and advance practice providers (APPs). PDSA 2 included educating physicians and measuring the compliance rate of the template. PDSA 3 addressed the barriers for compliance and education on resources was provided. PDSA 4 included education of the prior authorization staff and reinforcement of template use. A sustainability plan created consisting of a designated RN liaison for review of peer-to-peer requests for oncology scans. Results: PDSA 1: 100% of the nurse partners and APPs were educated. PDSA2: 80% of physicians were educated and 32.8% compliance rate of template use. PDSA 3: 39.2% compliance. PDSA 4: 95% of the radiology prior authorization staff was educated. While our compliance rate for the standardized order template use did increase, we identified many other opportunities to improve the process. Unfortunately, due to COVID-19 pandemic outbreak, resources have been temporarily allocated to relief efforts and the sustainability plan continues to be a work in progress. Conclusions: Peer to peer requests for imaging/scans following authorization denials consume time and effort of providers contributing to burnout and potentially impacting patient care. While many factors cannot be controlled, standardizing ordering process and educating the involved personnel may decrease the number for peer to peer requests. ASCO’s quality training program process helped our institution identify a provider controlled barrier and helped standardize this approach.

Negative reinforcement rate and persistent avoidance following response-prevention extinction

Persistent avoidance may be influenced by prior negative reinforcement rate (i.e., how effective the response is at controlling threat). In clinical settings, the effectiveness of extinction-based methods for treating anxiety-related avoidance may be impacted by prior reinforcement rate. Here, we conducted a laboratory-based treatment study to investigate the persistence of avoidance following response-prevention extinction (RPE) when prior avoidance had been differentially effective at cancelling shock. Participants in three negative reinforcement rate groups (100%, 50%, and 0%) completed a validated avoidance conditioning paradigm involving Pavlovian fear extinction, RPE, and re-extinction phases. It was hypothesised that partially reinforced avoidance would lead to diminished resistance to fear extinction following response prevention, compared to continuously- or never-reinforced avoidance. Persistent avoidance was related to prior negative reinforcement rate, with higher rates more resistant to extinction. These findings illustrate the role of reinforcement rate in the persistence of avoidance and may aid understanding of treatment relapse.

ACES

Many modern smart building applications are supported by wireless sensors to sense physical parameters, given the flexibility they offer and the reduced cost of deployment. However, most wireless sensors are powered by batteries today, and large deployments are inhibited by the requirement of periodic battery replacement. Energy harvesting sensors provide an attractive alternative, but they need to provide adequate quality of service to applications given the uncertainty of energy availability. We propose ACES, which uses reinforcement learning to maximize sensing quality of energy harvesting sensors for periodic and event-driven indoor sensing with available energy. Our custom-built sensor platform uses a supercapacitor to store energy and Bluetooth Low Energy to relay sensors data. Using simulations and real deployments, we use the data collected to continually adapt the sensing of each node to changing environmental patterns and transfer learning to reduce the training time in real deployments. In our 60-node deployment lasting 2 weeks, nodes stop operations only 0.1% of the time, and collection of data is comparable with current battery-powered nodes. We show that ACES reduces the node duty-cycle period by an average of 33% compared to three prior reinforcement learning techniques while continuously learning environmental changes over time.

Reduced Reward Responsiveness in Women With Moderate - to - Severe Premenstrual Syndrome: Evidence From a Probabilistic Reward Task.

Nearly 50% of women of reproductive age worldwide experience premenstrual syndrome (PMS). Women with PMS exhibit low positive affect and low frontal electroencephalography asymmetry scores, both of which are associated with reward processing. These findings suggest that women with PMS may exhibit deficiencies in reward processing. A probabilistic reward task based on signal detection approach was used to assess reward responsiveness in 30 women with moderate-to-severe PMS and 31 controls without PMS. The results revealed that in the late luteal phase, the women with moderate-to-severe PMS exhibited lower response bias and lower hit rate toward more frequently rewarded stimuli (rich stimuli) than the controls. By contrast, the response bias and hit rate did not differ between the two groups in the follicular phase. The group differences still remained after controlling for anhedonic symptoms. Furthermore, trial-by-trial probability analyses revealed that women with moderate-to-severe PMS exhibited a trend of having a higher miss rate for rich stimuli than the controls. In particular, when a rich stimulus was preceded by an infrequently rewarded stimulus (a rewarded lean stimulus), participants in the PMS group exhibited a trend for higher miss rate than those in the control group in the late luteal and follicular phases. However, group differences in the probability analyses were nonsignificant after controlling for anhedonic symptoms. These results provide preliminary evidence that women with moderate-to-severe PMS exhibit dysfunctional reward responsiveness and impaired ability to modulate their behavior as a function of prior reinforcement.

Reduced sensitivity to devaluation for instrumental but not consummatory behaviors in binge eating prone rats

Binge eating is characterized by the consumption of a large amount of palatable food in a short period of time and is a core feature of many eating disorders. Patients with eating disorders are also known to display impairments in inhibitory control, cognition and decision-making, which may promote and maintain binge eating symptomology. In the current study, we examined whether rats that were subsequently characterized as displaying a higher propensity to binge eat would show pre-existing deficits in reinforcer devaluation—a paradigm used to examine decision-making following reductions in the value of a food reinforcer. Female rats were first trained to respond on two levers for the delivery of two food reinforcers (sucrose and maltodextrin solutions). At the test stage, rats were provided 1 h access to one of the two reinforcers to allow for devaluation via sensory specific satiety, immediately followed by an extinction test with both levers. Normal rats typically show reductions in responding on the lever associated with the devalued reinforcer (i.e., intact goal-directed responding). Subsequently, we used intermittent access to palatable food to identify high (BE prone [BEP]; n = 14), intermediate (BE neutral [BEN]; n = 48), and low (BE resistant [BER]; n = 13) phenotypes of binge eating. Prior reinforcer devaluation performance showed BEN and BER rats suppressed responding on the lever associated with the devalued reinforcer while BEP rats did not. This insensitivity to instrumental reinforcer devaluation in BEP rats did not reflect impaired sensory-specific satiety as during a food choice test, BEP rats showed a more robust alteration in food preferences following devaluation. Additionally, across all rats sensory specific satiety was correlated with subsequent intake of palatable food. Collectively, these findings suggest dissociable effects of devaluation procedures on instrumental actions and consummatory behaviors in BEP rats, and may indicate that pre-existing differences in goal-directed behavior and sensory-specific satiety contribute to the propensity to overeat palatable food.

Model-free and model-based reward prediction errors in EEG

Learning theorists posit two reinforcement learning systems: model-free and model-based. Model-based learning incorporates knowledge about structure and contingencies in the world to assign candidate actions with an expected value. Model-free learning is ignorant of the world's structure; instead, actions hold a value based on prior reinforcement, with this value updated by expectancy violation in the form of a reward prediction error. Because they use such different learning mechanisms, it has been previously assumed that model-based and model-free learning are computationally dissociated in the brain. However, recent fMRI evidence suggests that the brain may compute reward prediction errors to both model-free and model-based estimates of value, signalling the possibility that these systems interact. Because of its poor temporal resolution, fMRI risks confounding reward prediction errors with other feedback-related neural activity. In the present study, EEG was used to show the presence of both model-based and model-free reward prediction errors and their place in a temporal sequence of events including state prediction errors and action value updates. This demonstration of model-based prediction errors questions a long-held assumption that model-free and model-based learning are dissociated in the brain.

Functional MRI in Awake Unrestrained Dogs

Because of dogs' prolonged evolution with humans, many of the canine cognitive skills are thought to represent a selection of traits that make dogs particularly sensitive to human cues. But how does the dog mind actually work? To develop a methodology to answer this question, we trained two dogs to remain motionless for the duration required to collect quality fMRI images by using positive reinforcement without sedation or physical restraints. The task was designed to determine which brain circuits differentially respond to human hand signals denoting the presence or absence of a food reward. Head motion within trials was less than 1 mm. Consistent with prior reinforcement learning literature, we observed caudate activation in both dogs in response to the hand signal denoting reward versus no-reward.

Transference effects of prior non-contingent reinforcement on the acquisition of temporal control on fixed-interval schedules

In two experiments we examined the influence of response and time factors on the speed of acquisition of temporal control on FI schedules. In Experiment 1, prior exposure to FT accelerated the development of temporal control on FI schedules of the same temporal value. It was also found that the slower acquisition on FI with prior RT was similar to that of rats with prior standard training. In Experiment 2, prior exposure to FT accelerated the development of temporal control on a FI schedule with a threefold increase in temporal value. Additionally, it was found that with prior FI 30s training, acquisition of temporal control on FI 90s was even faster than with prior FT 30s. Measures of head-entries into the feeder along the experiments indicated that temporal control was already developed during the periodic but not during the non-periodic histories and that this control transferred to lever press during FI testing phase.

The effects of basolateral amygdala lesions on unblocking.

Prior reinforcement of a neutral stimulus often blocks subsequent conditioning of a new stimulus if a compound of the original and new cues is paired with the same reinforcer. However, if the value of the reinforcer is altered when the compound is presented, the new cue typically acquires conditioning, a result called unblocking. Blocking, unblocking, and related phenomena have been attributed to variations in processing of either the reinforcer, for example, the Rescorla-Wagner (1972) model, or cues, for example, the Pearce-Hall (1980) model. Here, we examined the effects of lesions of the basolateral amygdala on the occurrence of unblocking when the food reinforcer was increased in quantity at the time of introduction of the new cue. The lesions had no effects on unblocking in a simple design (Experiment 1), which did not distinguish between unblocking produced by variations in reward or cue processing. However, in a procedure that distinguished between unblocking due to direct conditioning by the added reinforcer, consistent with the Rescorla-Wagner (1972) model, and that due to increases in conditioning to the original reinforcer, consistent with the Pearce-Hall (1980) and other models of learning, the lesions prevented unblocking of the latter type. These results were discussed in the context of roles of the basolateral amygdala in coding and using reward prediction error information in associative learning.

Social Learning, Reinforcement and Crime: Evidence from Three European Cities

This study reports a cross-cultural test of Social Learning Theory using direct measures of social learning constructs and focusing on the causal structure implied by the theory. Overall, the results strongly confirm the main thrust of the theory. Prior criminal reinforcement and current crime-favorable definitions are highly related in all three contexts and both strongly predict self-projections of criminal behavior. In addition, effects of prior reinforcement on projected misconduct appear to be both direct and indirect (through crime-favorable definitions). Yet, the findings also indicate that the processes underlying direct effects of reinforcement on criminal probabilities may need to be explicated further. Moreover, some types of definitions may be more influential than other types. Finally, parts of the reinforcement process may be affected by socio-cultural contexts.

RELATIONAL LEARNING IN A CONTEXT OF TRANSPOSITION: A REVIEW

In a typical transposition task, an animal is presented with a single pair of stimuli (for example, S3+ S4-, where plus and minus denote reward and nonreward and digits denote stimulus location on a sensory dimension such as size). Subsequently, an animal is presented with a testing pair that contains a previously reinforced or nonreinforced stimulus and a novel stimulus (for example, S2-S3 and S4-S5). Does the choice of a novel S2 instead of previously reinforced S3 in a testing pair S2-S3 indicate that the animal has learned a relation (i.e., "select smaller")? This review of empirical evidence and theoretical accounts shows that an organism's behavior in a transposition task is undoubtedly influenced by prior reinforcement history of the training stimuli (Spence, 1937). However, it is also affected by two other factors that are relational in nature-a similarity of two testing stimuli to each other and an overall similarity of the testing pair as a whole to the training pair as a whole. The influence of the two latter factors is especially evident in studies that use multiple pairs of training stimuli and a wide range of testing pairs comprising nonadjacent stimuli (Lazareva, Miner, Young, & Wasserman, 2008; Lazareva, Wasserman, & Young, 2005). In sum, the evidence suggests that both prior reinforcement history and relational information affect an animal's behavior in a typical transposition task.

Functional MRI in Awake Unrestrained Dogs

Because of dogs’ prolonged evolution with humans, many of the canine cognitive skills are thought to represent a selection of traits that make dogs particularly sensitive to human cues. But how does the dog mind dog actually work? To develop a methodology to answer this question, we trained two dogs to remain motionless for the duration required to collect quality fMRI images by using positive reinforcement without sedation or physical restraints. The task was designed to determine which brain circuits differentially respond to human hand signals denoting the presence or absence of a food reward. Head motion within trials was less than 1 mm. Consistent with prior reinforcement learning literature, we observed caudate activation in both dogs in response to the hand signal denoting reward versus no-reward.

Study on the Principle of Tunnel Collapse Treatment and its Application

Collapse of crowm broked out with large water gushing at working face during driving tunnel in Ming Ya Zi tunnel’s right tube. According to engineering geology condition and analysis of causes of collapse, double-deck prior ductile grouting reinforcement technique was applied in tunneling surrounding rock consolidation based on the strong pre-support theory.And the result of treatment was successful.Thus,guiding the work of tunnel collapse treatment by strong pre-support theory was proved reasonably and effectively.

Attentional effects of lesions to the anterior cingulate cortex: How prior reinforcement influences distractibility.

Morphological changes in the anterior cingulate cortex are found in subjects with schizophrenia, attention deficit hyperactivity disorder, and obsessive-compulsive disorder. These changes are hypothesized to underlie the impairments these individuals show on tasks that require cognitive control. The anterior cingulate cortex has previously been shown to be active in situations involving high conflict, presentation of salient, distracting stimuli, and error processing, that is, situations that occur when a shift in attention or responding is required. However, there is some uncertainty as to what specific role the anterior cingulate cortex plays in these situations. The current study used converging evidence from two behavioral paradigms to determine the effects of excitotoxic lesions in the anterior cingulate cortex on executive control. The first assay tests reversal learning, attentional set formation and shifting. The second assesses sustained attention with and without distractors. Animals with anterior cingulate cortex lesions were impaired during reinforcement reversals, discriminations that required subjects to disregard previously relevant stimulus attributes and showed a more rapid decline in attentional ability than Sham-Lesioned subjects when maintaining sustained attention for extended periods of time. These results are consistent with the hypothesis that the anterior cingulate cortex is involved in attending to stimulus attributes that currently predict reinforcement in the presence of previously relevant, salient distractors and maintaining sustained attention over prolonged time on task.

P.1.e.00l A dynamic [18F]-fally pride PET study: measuring dopamine neuromodulation in the extrastriatal reward circuit

Introduction: Animal research indicates the mesocorticolimbic pathway as the central circuit of the brain reward system, with dopamine (DA) as the most important neurotransmitter (1). Previous studies propose that the extrastriatal part of the reward circuit plays a role in the ability to experience pleasure (liking the reward), but also in behaviours like motivation and drive (wanting the reward and learning). It is hypothesized that these psychological subcomponents of reward correspond with specific neural areas in the extrastriatal reward pathway in the brain. Purpose: The purpose of this study was first to examine presynaptic DA release in extrastriatal regions of the reward circuit, in particular the prefrontal cortex (PFC) and anterior cingulate cortex (ACC), by measuring the high affinity D 2 /D 3 radioligand [ 18 F]-fallypride binding potential in response to a monetary reward challenge and second to identify the specific neural subcomponents in this part of the reward system in the brain. Methods: 10 healthy volunteers underwent a single [ 18 F]fallypride injection Positron Emission tomography imaging session (2) while executing a computerized probabilistic reward task (3). DA-release in the extrastriatal reward areas of the brain was statistically tested by measuring time-dependent alterations in the kinetics of [18F]fallypride using the linearized simplified reference region model (LSRRM). Statistic images, reflecting DA changes, were calculated and correlated with reward responsiveness, and feedbackrelated behaviour (learning and reward anticipation) by trail by trail probabilistic reward analysis . Results: Voxel-based analysis revealed a significant inverse correlation between reward capacity and DArelease in the ventralmedial PFC (BA 10), orbitofrontal PFC (BA 11) and ACC (BA 32). Furthermore, the ACC and thalamic DA-displacement showed a significant positive correlation with the impaired tendency to modulate behavior as a function of prior reinforcements. Conclusion: These findings support the hypothesis that several extrastriatal areas of the brain are involved in reward capacity. Individuals with a lower reward responsiveness show a higher DA release in prefrontal areas and the ACC during a reward challenge. Furthermore, integration of reinforcement history over time inversely correlates with thalamic and ACC DA release BACKGROUND