Implicit Reward Research Articles

Implicit and explicit reward learning in chronic nicotine use

BackgroundChronic tobacco use is related to specific neurobiological alterations in the dopaminergic brain reward system that can be termed “reward deficiency syndrome” in dependent nicotine consumers. The close linkage of dopaminergic activity and reward learning led us to expect implicit and explicit reward learning deficits in dependent compared to non-smokers. Smokers who maintain a less regular, occasional use may also, to a lesser extent, show implicit reward learning deficits. The purpose of our study was to examine the behavioral effects of the neurobiological alterations on reward related learning. We also tested whether any deficits observed in an abstinent state are also present in a satiated state. MethodsIn two studies, we examined implicit and explicit reward learning in smokers. Participants were administered a probabilistic implicit reward learning task, and an explicit reward- and punishment-based trial-and-error learning task. In Study 1, we compared dependent, occasional, and non-smokers, and in Study 2 satiated and abstinent smokers. ResultsIn Study 1, chronic and occasional smokers showed impairments in both, implicit and explicit reward learning tasks. In Study 2, satiated smokers did not perform better than abstinent smokers. ConclusionsThe results support the hypothesis of reward learning deficits. These deficits are not limited to explicit but extend to implicit reward learning and cannot be explained by tobacco withdrawal.

Functional polymorphism of the mu-opioid receptor gene (OPRM1) influences reinforcement learning in humans.

Previous reports on the functional effects (i.e., gain or loss of function), and phenotypic outcomes (e.g., changes in addiction vulnerability and stress response) of a commonly occurring functional single nucleotide polymorphism (SNP) of the mu-opioid receptor (OPRM1 A118G) have been inconsistent. Here we examine the effect of this polymorphism on implicit reward learning. We used a probabilistic signal detection task to determine whether this polymorphism impacts response bias to monetary reward in 63 healthy adult subjects: 51 AA homozygotes and 12 G allele carriers. OPRM1 AA homozygotes exhibited typical responding to the rewarded response—that is, their bias to the rewarded stimulus increased over time. However, OPRM1 G allele carriers exhibited a decline in response to the rewarded stimulus compared to the AA homozygotes. These results extend previous reports on the heritability of performance on this task by implicating a specific polymorphism. Through comparison with other studies using this task, we suggest a possible mechanism by which the OPRM1 polymorphism may confer reduced response to natural reward through a dopamine-mediated decrease during positive reinforcement learning.

Study on Competition Motivation to the Intention of Adventurous Players

Research on behavioral intention model theory, with the national equestrian team, national basketball team and the 2010 National University Games 120 athletes (including 60 male athletes, the athletes belong to the collective project of 60) as the experimental objects, Started by the method of implicit cues and reward leads the race on the movement of risk behaviors reported.

Altered social reward and attention in anorexia nervosa

Dysfunctional social reward and social attention are present in a variety of neuropsychiatric disorders including autism, schizophrenia, and social anxiety. Here we show that similar social reward and attention dysfunction are present in anorexia nervosa (AN), a disorder defined by avoidance of food and extreme weight loss. We measured the implicit reward value of social stimuli for female participants with (n = 11) and without (n = 11) AN using an econometric choice task and also tracked gaze patterns during free viewing of images of female faces and bodies. As predicted, the reward value of viewing bodies varied inversely with observed body weight for women with anorexia but not control women, in contrast with their explicit ratings of attractiveness. Surprisingly, women with AN, unlike control women, did not find female faces rewarding and avoided looking at both the face and eyes – independent of observed body weight. These findings suggest comorbid dysfunction in the neural circuits mediating gustatory and social reward in anorexia nervosa.

Parkinson's disease and dopaminergic therapy—differential effects on movement, reward and cognition

Cognitive deficits are very common in Parkinson's disease particularly for ‘executive functions’ associated with frontal cortico-striatal networks. Previous work has identified deficits in tasks that require attentional control like task-switching, and reward-based tasks like gambling or reversal learning. However, there is a complex relationship between the specific cognitive problems faced by an individual patient, their stage of disease and dopaminergic treatment. We used a bimodality continuous performance task during fMRI to examine how patients with Parkinson's disease represent the prospect of reward and switch between competing task rules accordingly. The task-switch was not separately cued but was based on the implicit reward relevance of spatial and verbal dimensions of successive compound stimuli. Nineteen patients were studied in relative ‘on’ and ‘off’ states, induced by dopaminergic medication withdrawal (Hoehn and Yahr stages 1–4). Patients were able to successfully complete the task and establish a bias to one or other dimension in order to gain reward. However the lateral prefrontal cortex and caudate nucleus showed a non-linear U-shape relationship between motor disease severity and regional brain activation. Dopaminergic treatment led to a shift in this U-shape function, supporting the hypothesis of differential neurodegeneration in separate motor and cognitive cortico–striato–thalamo–cortical circuits. In addition, anterior cingulate activation associated with reward expectation declined with more severe disease, whereas activation following actual rewards increased with more severe disease. This may facilitate a change in goal-directed behaviours from deferred predicted rewards to immediate actual rewards, particularly when on dopaminergic treatment. We discuss the implications for investigation and optimal treatment of this common condition at different stages of disease.

Activation of insular cortex and subcortical regions related to feedback stimuli in a time estimation task: An fMRI study

We used functional magnetic resonance imaging to investigate brain activity related to motivational function of informative feedback stimuli in a time estimation task. In that task, subjects pressed a button as a response 3 s after a cue stimulus; a visual feedback stimulus was presented 2 s after the response. In a true feedback condition, subjects received true information (informative feedback) about their time-estimation performance. In the false feedback condition, the same visual signs were used, but they were presented randomly. Therefore, they were not related to actual performance. In the 20 subjects examined, higher hemodynamic responses were identified in the insular cortex, the thalamus, and the striatum by comparing the true feedback condition to the false feedback condition. The time estimation performance and subjective score on motivation were also markedly higher in the true feedback condition. The anterior insular cortex and striatal regions are known to be involved in motivational and reward processing. Therefore, the hemodynamic responses observed in this study suggest that the motivational function of the feedback information is a crucial factor for behavioral learning; it is considered that the informative feedback might serve as an implicit reward for humans.

Eco-Dumping, Capital Mobility, and International Trade

A small open economy’s optimal environmental policy is studied in a model with international capital mobility and local pollution. The country produces traded as well as non-traded goods. Is it in the country’s interest to engage in ecological dumping by choosing generous pollution allowances for the traded-good sector? The answer depends decisively on the policy regime in use. Dumping is not optimal if the country ensures that the implicit rent on pollution is completely appropriated within the country. However, if the implicit factor reward on pollution leaves the country because it accrues to (foreign) owners of mobile capital, the local welfare maximizing government tends to discriminate against the traded-good sector, the opposite of ecological dumping.

Giving a Reason for Unfairness: Effects of a Rationale Upon Australian Students' Performances Within an Implicit Reward Situation

Two experimental conditions (giving a rationale vs no-rationale for “unfair” rewards) were compared under an implicit reward paradigm in which “target” subjects received rewards directly and contingently for improvements on a simple motor skills task while “peer” subjects who were also performing the same task received no rewards. Data showed that there were significant reinforcement effects on the behavior of both target and peer subjects during the implicit reward situation when no rationale was given for the “unfair” application of rewards. However, when a rationale was given for the non-reward of the peer subjects, neither target nor peer subjects showed significant increases in responses from baseline. Implications for group reinforcement practices are discussed. Deux conditions expérimentales (donner ou ne pas donner de raisons pour des récompenses “injustes”) ont été comparées à l'aide d'un paradigme de récompense implicite dans lequel les sujets “cibles” recevaient directement des récompenses contingentes à des améliorations lors d'une tâche d'habileté motrice simple, tandis que les sujets “pairs” qui accomplissaient également la měme tâche ne recevaient aucune récompense. Les résultats démontrent qu'il existe des effets significatifs de renforçement sur le comportement des sujets cibles et pairs durant la situation de récompense implicite lorsqu'aucune raison n'est donnée pour la remise “injuste” de récompenses. Toutefois, lorsqu'une raison est fournie pour le fait de ne pas récompenser les sujets pairs, ni les sujets cibles ou pairs dénotent des accroissements significatifs dans leur taux de réponse par rapport au niveau de base. Les implications de ces résultats pour les pratiques de renforçement de groupe sont discutées.

The Effects of Pre-experience on Performance Within an Implicit Reward Situation

The effects of implicit rewards upon adults' performance were examined in a study which replicated the design and procedures of previous research using children as subjects. Data revealed that unlike children, the adults in the present study did not show implicit extinction effects under certain experimental conditions. However, there were significant inconsistencies in performance across the two different conditions contrasted here, indicating effects attributable to the implicit reward paradigm and the order in which it occurs relative to other reward conditions.

Effects of varying contingency and directness of rewards upon children's performance under implicit reward conditions

The application of verbal praise as a reward for completion of a digit-symbol coding task was investigated under contingent versus noncontingent and direct versus implicit reward conditions. Results from two studies were compared with control (no-reward) data, all collected over eight trials of the coding task. Subjects were 84 third and fourth grade children, and results indicated that noncontingent rewards possessed no significant reinforcer effect under either direct or implicit reward conditions. By comparison, contingent rewards administered directly were reinforcing, but contingent rewards administered implicitly were not. Results are discussed in terms of the relative power of directness and contingency as determinants of reinforcer effect. Consideration of the detrimental effects which implicit rewards may have upon the success of child behavior modification procedures could explain the apparent “failure” of such strategies in some instances.

Implicit rewards in the classroom

Although well established in a range of situations, the application of operant methodologies to typical classrooms is often difficult for teachers because of logistic considerations which may lead to a subgroup of a class being rewarded, with peers showing performance decrement. This paper reviews the use of “vicarious” and “implicit” rewards in both special and normal classrooms, critically examining previous literature and concluding that several key issues are open to speculation. A series of four further studies which were designed to investigate some of these issues and overcome some of the design and methodology flaws of previous research are reported, with several important distinctions being drawn between “vicarious reinforcement” effects and outcomes from “implicit reward” situations. Criterion variables are discussed, with several key findings suggesting that the concept of vicarious reinforcement as based upon the general literature is simplistic and inaccurate. Suggestions are made for the successful use of “implicit reward” procedures in the classroom.

Implicit rewards as reinforcers and extinguishers

Previous studies of implicit reinforcement with children have presented the implicit reward phase after baseline conditions. The present study replicated this design and compared these effects within a design where implicit rewards were presented after direct rewards to both targets and peers. Thirty-two fourth grade children copied the letters of the alphabet under varying reward conditions. Data indicated the presence of reinforcement effects when presented after baseline, and extinction effects when presented after direct reward conditions.

Rewards for unsafe driving? A rejoiner to P.M. Hurst

Recently, Hurst has argued that attempts to reward safe driving are likely to be futile. However, he argues that existing punitive systems have within them an implicit reward structure; persons who drive while disqualified are “rewarded” for driving safely (i.e. they avoid apprehension) and, as a consequence of this reinforcement, safe driving becomes habitual. This paper argues that Hurst's analysis may be based upon an erroneous interpretation of the motivational effects inherent in disqualification. The behavior learned while driving under suspension may not be safe driving, but rather proficiency at avoiding apprehension. Such a proposition has implications for Hurst's formulation inasmuch as the major source of “reward” within punitive systems consists of satisfaction gained in successfully breaking the law. This paper discusses some necessary pre-conditions for the implementation of more conventional reward structures.

Elimination of vicarious reinforcement effects within an implicit reward situation.

Elimination of vicarious reinforcement effects within an implicit reward situation.

Elimination of vicarious reinforcement effects within an implicit reward situation.

Elimination of vicarious reinforcement effects within an implicit reward situation.