Change in motivational bias during treatment predicts outcome in anorexia nervosa

OBJECTIVE

Reward and punishment sensitivity are known to be altered in anorexia nervosa (AN). Most research has examined these constructs separately although motivated behavior is influenced by considering both the potential for reward and risk of punishment. The present study sought to compare the relative balance of reward and punishment sensitivity in AN versus healthy controls (HCs) and examine whether motivational bias is associated with AN symptoms and treatment outcomes.

METHODS

Adolescents and adults with AN (n = 262) in a partial hospitalization program completed the Eating Disorders Examination Questionnaire (EDE-Q), Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) scales, and Sensitivity to Punishment/Sensitivity to Reward Questionnaire (SPSRQ) at admission and discharge. HCs (HC; n = 90) completed the BIS/BAS and SPSRQ. Motivational Bias Scores were calculated to reflect the dominance of reward versus punishment sensitivity.

RESULTS

Individuals with AN demonstrated significantly greater bias toward punishment sensitivity than HC. In AN, a bias toward punishment was associated with higher EDE-Q Global score at admission. Change in motivational bias during treatment predicted EDE-Q Global scores, but not BMI, at discharge, with greater increases in reward sensitivity or greater decreases in punishment sensitivity during treatment predicting lower eating pathology. Similar findings were observed using the BIS/BAS and SPSRQ.

DISCUSSION

Change in motivational bias during treatment is associated with improved outcomes in AN. However, it appears that much of the change in motivational bias can be attributed to changes in punishment sensitivity, rather than reward sensitivity. Future research should examine the mechanisms underlying punishment sensitivity decreases during treatment.

PUBLIC SIGNIFICANCE

Sensitivity to reward and punishment may be important treatment targets for individuals with anorexia nervosa (AN). To date, most research has considered reward and punishment sensitivity separately, rather than examining their relationship to each other. We found that the balance of reward and punishment sensitivity (i.e., motivational bias) differs between healthy controls and those with AN and that this bias is associated with eating disorder symptoms and treatment outcome.

Punishment sensitivity and the persistence of anorexia nervosa: High punishment sensitivity is related to a less favorable course of anorexia nervosa

OBJECTIVE

Cross-sectional research provides robust evidence that individuals with anorexia nervosa (AN) report higher punishment sensitivity (PS) than individuals without an eating disorder (ED). High PS might interfere with treatment motivation and the ability to learn from experience. The current study took a longitudinal approach to test predictions that follow from the proposed relevance of PS as a factor in the persistence of AN symptoms. More specifically we tested (1) if higher PS at the start of treatment was related to less improvement in ED symptoms after one year, and (2) if a decrease in ED symptoms was associated with a concurrent decrease in PS.

METHOD

Participants were 69 adolescents with a diagnosis of AN at the start of treatment of whom 62 participated again one year later. ED symptom severity and PS were assessed at both time points.

RESULTS

Findings showed that (1) higher PS at the start of treatment was related to less improvement in ED symptoms, and (2) an improvement in ED symptoms was related to a decrease in PS.

DISCUSSION

These findings are consistent with the proposed relevance of PS in the persistence of AN and suggest that it might be beneficial to address high PS in treatment.

PUBLIC SIGNIFICANCE

Consistent with the view that punishment sensitivity (PS) is related to the persistence of anorexia nervosa, high PS at the start of treatment was related to less improvement in eating disorder symptoms in patients with anorexia nervosa. Furthermore, an improvement in eating disorder symptoms was associated with a concurrent decrease in PS, suggesting that PS can be subject to change and may be a relevant target for treatment.

Serotonin and early life stress interact to shape brain architecture and anxious avoidant behavior - a TPH2 imaging genetics approach

BACKGROUND

Early life stress has been associated with emotional dysregulations and altered architecture of limbic-prefrontal brain systems engaged in emotional processing. Serotonin regulates both, developmental and experience-dependent neuroplasticity in these circuits. Central serotonergic biosynthesis rates are regulated by Tryptophan hydroxylase 2 (TPH2) and transgenic animal models suggest that TPH2-gene associated differences in serotonergic signaling mediate the impact of aversive early life experiences on a phenotype characterized by anxious avoidance.

METHODS

The present study employed an imaging genetics approach that capitalized on individual differences in a TPH2 polymorphism (703G/T; rs4570625) to determine whether differences in serotonergic signaling modulate the effects of early life stress on brain structure and function and punishment sensitivity in humans (n = 252).

RESULTS

Higher maltreatment exposure before the age of 16 was associated with increased gray matter volumes in a circuitry spanning thalamic-limbic-prefrontal regions and decreased intrinsic communication in limbic-prefrontal circuits selectively in TT carriers. In an independent replication sample, associations between higher early life stress and increased frontal volumes in TT carriers were confirmed. On the phenotype level, the genotype moderated the association between higher early life stress exposure and higher punishment sensitivity. In TT carriers, the association between higher early life stress exposure and punishment sensitivity was critically mediated by increased thalamic-limbic-prefrontal volumes.

CONCLUSIONS

The present findings suggest that early life stress shapes the neural organization of the limbic-prefrontal circuits in interaction with individual variations in the TPH2 gene to promote a phenotype characterized by facilitated threat avoidance, thus promoting early adaptation to an adverse environment.

Why Dieters Succeed or Fail: The Relationship Between Reward and Punishment Sensitivity and Restrained Eating and Dieting Success

BACKGROUND

The current study set out to improve our understanding of the characteristics of individuals who are motivated to restrict their food intake yet who nevertheless fail to do so. We examined whether punishment sensitivity (PS) was related to restrained eating, and reward sensitivity (RS) to perceived dieting success. Additionally, it was examined whether executive control (EC) moderates the association between RS and perceived dieting success.

METHODS

Female student participants (N = 290, aged 17-29, BMI between 18.5 and 38.0) completed questionnaires on restrained eating, perceived dieting success, RS and PS, and carried out a behavioral task to index EC.

RESULTS

PS was indeed positively related to restrained eating. RS was positively related to perceived dieting success, yet, EC did not moderate this association.

CONCLUSION

The current study adds to the evidence that PS is related to individuals' motivation to restrict their food intake. Furthermore, it shows support for the suggestion that RS may facilitate food restriction.

Does the Punishment Fit the Crime (and Immune System)? A Potential Role for the Immune System in Regulating Punishment Sensitivity

Although the criminal justice system is designed around the idea that individuals are invariant in their responses to punishment, research indicates that individuals exhibit a tremendous amount of variability in their punishment sensitivity. This raises the question of why; what are the individual- and situation-level variables that impact a person’s sensitivity to punishment? In the current research, we synthesize theory and research on inflammation, learning, and evolutionary biology to examine the relationship between inflammatory activity and sensitivity to punishment. These theories combine to predict that inflammatory activity – which is metabolically costly and reflects a context in which the net payoff associated with future oriented behaviors is diminished – will decrease sensitivity to punishment, but not rewards. Consistent with this hypothesis, Study 1 found that in U.S. states with a higher infectious disease burden (a proxy for average levels of inflammatory activity) exhibit harsher sentencing in their criminal justice systems. Studies 2 and 3 experimentally manipulated variables known to impact bodily inflammatory activity and measured subsequent punishment and reward sensitivity using a probabilistic selection task. Results revealed that (a) increasing inflammation (i.e., completing the study in a dirty vs. clean room) diminished punishment sensitivity (Study 2), whereby (b) administering a non-steroidal anti-inflammatory drug, suppressing inflammatory activity, enhanced it. No such changes were found for reward sensitivity. Together, these results provide evidence of a link between the activities of the immune system and punishment sensitivity, which may have implications for criminal justice outcomes.

A model of reinforcement sensitivity, impulsivity, alcohol use, and risky sexual behavior in a sample of young adult drinkers

This study tested a structural equation model linking reinforcement sensitivity to subsequent emotion-based impulsivity (i.e., positive and negative urgency), alcohol use, and risky sexual behavior among a sample of 753 undergraduate drinkers. A hypothesized Sensitivity to Punishment (SP) × Sensitivity to Reward (SR) interaction significantly predicted both positive and negative urgency. At low levels of SR, SP had a significant negative effect on positive urgency and a significant positive effect on negative urgency. However, at high levels of SR, SP had significant positive effects on both types of urgency. Results indicated that positive and negative urgency mediate the associations between reinforcement sensitivity and both alcohol use and risky sexual behavior. Moreover, results demonstrated that at low levels of SR, SP is indirectly associated with decreased alcohol use. However, as SR increases, SP is indirectly associated with increased alcohol use and risky sexual behavior, due to the joint effect of high SP and SR on emotion-based impulsivity. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

No Differential Reward Responsivity and Drive, Punishment Sensitivity or Attention for Cues Signaling Reward or Punishment in Adolescents With Obesity

Although it has been proposed that obese and healthy weight individuals might differ in their reward and punishment sensitivity, the literature shows diverse and inconsistent findings. The current study was set out to examine the role of reward and punishment sensitivity in adolescent obesity by differentiating between reward responsivity and reward drive, and by complementing self-report measures with performance-based measures indexing attention for cues signaling reward and punishment as well as effort to approach reward and avoid punishment. Participants were adolescents aged 12-23, with obesity (n = 51, adjusted BMI [(actual BMI/Percentile 50 of BMI for age and gender) × 100) between 143 and 313%], and with a healthy weight (n = 51, adjusted BMI between 75 and 129%). Individuals with obesity did not significantly differ from adolescents with a healthy weight in reward responsivity, reward drive or attention to cues signaling reward. Further, no differences in self-reported punishment sensitivity or attention for cues signaling punishment were found between obese and healthy weight adolescents. The current study thus does not corroborate the theories that general reward and punishment sensitivity play a role in obesity.

Posterior Cingulate Cortical Response to Active Avoidance Mediates the Relationship between Punishment Sensitivity and Problem Drinking

Many people drink to alleviate negative affect, reflecting an avoidance strategy which can lead to alcohol misuse. Individuals with heightened sensitivity to punishment (SP) are especially susceptible to problem drinking via this maladaptive coping mechanism. As imaging studies have largely focused on sensation-seeking traits and approach behavior, the neural substrates underlying behavioral avoidance as well as their relationship with punishment sensitivity and alcohol use remain unclear. Here, we examined in humans the cerebral correlates of response inhibition to avoid a penalty in relation to both problem drinking and SP, as evaluated by the Alcohol Use Disorders Identification Test and the Sensitivity to Punishment and Sensitivity to Reward Questionnaire, respectively. Seventy nondependent female and male drinkers performed a reward go/no-go task with approximately two-thirds go and one-third no-go trials. Correct go and no-go responses were rewarded, and incorrect responses were punished. The results showed that SP and Alcohol Use Disorders Identification Test scores were both positively correlated with brain activations during response inhibition, and these activations overlapped in the posterior cingulate cortex (PCC). Thus, the PCC may represent a shared neural substrate for avoidance, punishment sensitivity, and problem drinking. Mediation analyses further suggested that PCC response to avoidance completely and bidirectionally mediated the relationship between SP and hazardous alcohol use. These findings substantiated the role of the PCC in behavioral avoidance and its link to problem drinking in punishment-sensitive nondependent drinkers.SIGNIFICANCE STATEMENT Many people drink to alleviate negative affect, reflecting an avoidance strategy that can lead to alcohol misuse. Individuals with heightened punishment sensitivity (SP) trait are particularly vulnerable to this maladaptive coping mechanism. The current study examined the neural substrates underlying behavioral avoidance and their relationship with SP and problem drinking. Using a reward go/no-go task, we showed both SP and drinking severity were positively correlated with the posterior cingulate cortex (PCC) activation during action inhibition. Thus, the PCC may represent a shared neural substrate for avoidance behavior, punishment sensitivity, and problem drinking. Further, PCC response to avoidance mediated the relationship between SP and alcohol use. These findings substantiated the neural processes linking avoidance tendency to alcohol misuse in punishment-sensitive drinkers.

Depression and Sequential Decision-Making Revisited

Background: The effect of depression on decision-making is an important but still an unsettled issue. Although most studies have reported that clinically depressed participants show worse performance, there are also studies that have shown no or even positive effects. Specifically, von Helversen et al. (2011) were able to document a positive effect of depression on task performance in a sequential decision-making task called the secretary problem (SP). Here, we (1) aimed to replicate this study in an extended version using more trials and (2) modified it by including an additional condition in which negative feedback was given.

Method: Eighty-two participants took part. They were split into two groups: 20/21 participants with major depression disorder (MDD) and 20/21 matched healthy participants. Participants completed the secretary problem either in the standard or in a modified version. Additionally, they answered questionnaires for assessing depression, personality, and intelligence.

Results: We did not find any significant differences between clinically depressed and nondepressed individuals in any indicators of task performance, under both the original and modified conditions.

Limitations: Our participants were ambulatory patients. The quality of depression may have been therefore less extreme. We did not assess or control for rumination.

Conclusions: We were not able to detect any significant differences between the performances of healthy and clinically depressed participants in a sequential decision-making task.

Morningness-eveningness and social anxiety symptoms: the influence of depression symptoms on the indirect effect through punishment sensitivity and experiential avoidance

Social anxiety has recently been linked to morningness-eveningness; however, the psychological mechanisms underlying this relationship are not well known. As such, the purpose of the current study is to propose a model by which morningness-eveningness is related to social anxiety symptoms through punishment sensitivity and experiential avoidance within an adult American, community sample recruited via Amazon's Mechanical Turk (MTurk). It was hypothesized that experiential avoidance and punishment sensitivity would be associated with increased social anxiety symptoms and that morningness-eveningness would be negatively related to social anxiety symptoms. Furthermore, eveningness was hypothesized to be associated with increased punishment sensitivity and in turn, greater experiential avoidance. Lastly, the relationship between morningness-eveningness and social anxiety was hypothesized to be mediated by punishment sensitivity among the group with high depression levels, but not among the group with lesser depression symptoms. The results indicated that eveningness was related to social anxiety symptoms through experiential avoidance, and that depression symptoms influenced the relationship between morningness-eveningness and punishment sensitivity such that, in those high in depression symptoms, there was a significant association between eveningness and punishment sensitivity, but not among those with lower depression levels. The study findings build upon existing chronobiological research and addresses inconsistencies in previous literature.

The Interaction Between Punishment Sensitivity and Effortful Control for Emerging Adults' Substance Use Behaviors

BACKGROUND

Within the dual systems perspective, high reward sensitivity and low punishment sensitivity in conjunction with deficits in cognitive control may contribute to high levels of risk taking, such as substance use.

OBJECTIVE

The current study examined whether the individual components of effortful control (inhibitory control, attentional control, and activation control) serve as regulators and moderate the association between reward or punishment sensitivity and substance use behaviors.

METHOD

A total of 1,808 emerging adults from a university setting (Mean age = 19.48; 72% female) completed self-report measures of reward and punishment sensitivity, effortful control, and substance use.

RESULTS

Findings indicated significant two-way interactions for punishment sensitivity and inhibitory control for alcohol and marijuana use. The form of these interactions revealed a significant negative association between punishment sensitivity and alcohol and marijuana use at low levels of inhibitory control. No significant interactions emerged for reward sensitivity or other components of effortful control.

CONCLUSIONS

The current findings provide preliminary evidence suggesting the dual systems theorized to influence risk taking behavior interact to make joint contributions to health risk behaviors such as substance use in emerging adults.

Clinical Depression and Punishment Sensitivity on the BART

Depression is associated with altered sensitivity to reward and punishment, which can influence complex decision-making. We examined punishment sensitivity in the performance of participants with major depressive disorder (MDD) with that of a comparison group on the automatic Balloon Analogue Risk Task (BART), which is a direct measure of risk taking. The present study examined the BART performance of 30 individuals with MDD and 30 matched comparison individuals. The comparison group (M = 63.25) entered a significantly (p < 0.001; d = 1.1) higher number of pumps on the BART than the MDD group (M = 50.83). Higher levels of depression symptoms were significantly correlated (r = -0.40, p < 0.05) with entering a lower number of pumps in the MDD group. MDD patients showed an increased sensitivity to punishment on the BART: after a loss, the MDD group decreased (M = 13.7) the number of subsequent pumps they entered by a significantly (p < 0.001, d = 0.81) greater amount than the comparison group (M = 4.35). This difference applied to losses only: no difference was found between the groups regarding the magnitude of change in pumps selected after a win. Findings suggest the presence of elevated punishment sensitivity among individuals with MDD, which may contribute to the maintenance of depressive symptoms.

The impact of precommitment on risk-taking while gambling: A preliminary study

Background and aims Precommitment refers to the ability to prospectively restrict the access to temptations. This study examined whether risk-taking during gambling is decreased when an individual has the opportunity to precommit to his forthcoming bet. Methods Sixty individuals participated in a gambling task that consisted of direct choice (simply chose one monetary option among four available ones, ranging from low-risk to high-risk options) or precommitment trials (before choosing an amount, participants had the opportunity to make a binding choice that made high-risk options unavailable). Results We found that participants utilized the precommitment option, such that risk-taking was decreased on precommitment trials compared to direct choices. Within the precommitment trials, there was no significant difference in risk-taking following decisions to restrict versus non-restrict. Discussion These findings suggest that the opportunity to precommit may be sufficient to reduce the attractiveness of risk. Conclusions Present results might be exploited to create interventions aiming at enhancing one's ability to anticipate self-control failures while gambling.

Individual differences in sensitivity to reward and punishment and neural activity during reward and avoidance learning

In this functional neuroimaging study, we investigated neural activations during the process of learning to gain monetary rewards and to avoid monetary loss, and how these activations are modulated by individual differences in reward and punishment sensitivity. Healthy young volunteers performed a reinforcement learning task where they chose one of two fractal stimuli associated with monetary gain (reward trials) or avoidance of monetary loss (avoidance trials). Trait sensitivity to reward and punishment was assessed using the behavioral inhibition/activation scales (BIS/BAS). Functional neuroimaging results showed activation of the striatum during the anticipation and reception periods of reward trials. During avoidance trials, activation of the dorsal striatum and prefrontal regions was found. As expected, individual differences in reward sensitivity were positively associated with activation in the left and right ventral striatum during reward reception. Individual differences in sensitivity to punishment were negatively associated with activation in the left dorsal striatum during avoidance anticipation and also with activation in the right lateral orbitofrontal cortex during receiving monetary loss. These results suggest that learning to attain reward and learning to avoid loss are dependent on separable sets of neural regions whose activity is modulated by trait sensitivity to reward or punishment.

Body weight status, eating behavior, sensitivity to reward/punishment, and gender: relationships and interdependencies

Behavioral and personality characteristics are factors that may jointly regulate body weight. This study explored the relationship between body mass index (BMI) and self-reported behavioral and personality measures. These measures included eating behavior (based on the Three-Factor Eating Questionnaire; Stunkard and Messick, 1985), sensitivity to reward and punishment (based on the Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) scales) (Carver and White, 1994) and self-reported impulsivity (based on the Barratt Impulsiveness Scale-11; Patton et al., 1995). We found an inverted U-shaped relationship between restrained eating and BMI. This relationship was moderated by the level of disinhibited eating. Independent of eating behavior, BIS and BAS responsiveness were associated with BMI in a gender-specific manner with negative relationships for men and positive relationships for women. Together, eating behavior and BIS/BAS responsiveness accounted for a substantial proportion of BMI variance (men: ∼25%, women: ∼32%). A direct relationship between self-reported impulsivity and BMI was not observed. In summary, our results demonstrate a system of linear and non-linear relationships between the investigated factors and BMI. Moreover, body weight status was not only associated with eating behavior (cognitive restraint and disinhibition), but also with personality factors not inherently related to an eating context (BIS/BAS). Importantly, these relationships differ between men and women.

Multidimensional examination of impulsivity in relation to disordered gambling

Impulsivity has been consistently associated with pathological gambling (PG), but the diversity of definitions and measures of impulsivity has led to ambiguity with regard to which indices are independently relevant. Toward clarifying this relationship, the current study examined indices from an array of commonly used impulsivity measures in relation to PG severity in an adult community sample of frequent gamblers (N = 353). These included both survey assessments and behavioral tasks. Using a factor analytic approach, 4 latent factors were identified among 19 indices and were designated reward sensitivity, punishment sensitivity, delay discounting, and cognitive impulsivity. All 4 latent variables were positively and independently related to PG severity, albeit at a trend level for cognitive impulsivity in a combined model. These findings reveal 4 generally independent domains of impulsivity that are related to PG severity, clarify which assessment measures aggregate in each domain, and illustrate the importance of measurement specificity in studying impulsivity in relation to PG and other psychiatric disorders.

Differential impairments underlying decision making in anorexia nervosa and bulimia nervosa: a cognitive modeling analysis

OBJECTIVE

This study examined the underlying processes of decision-making impairments in individuals with anorexia nervosa (AN) and bulimia nervosa (BN). We deconstructed their performance on the widely used decision task, the Iowa Gambling Task (IGT) into cognitive, motivational, and response processes using cognitive modeling analysis. We hypothesized that IGT performance would be characterized by impaired memory functions and heightened punishment sensitivity in AN, and by elevated sensitivity to reward as opposed to punishment in BN.

METHOD

We analyzed trial-by-trial data of IGT obtained from 224 individuals: 94 individuals with AN, 63 with BN, and 67 healthy comparison individuals (HC). The prospect valence learning model was used to assess cognitive, motivational, and response processes underlying IGT performance.

RESULTS

Individuals with AN showed marginally impaired IGT performance compared to HC. Their performance was characterized by impairments in memory functions. Individuals with BN showed significantly impaired IGT performance compared to HC. They showed greater relative sensitivity to gains as opposed to losses than HC. Memory functions in AN were positively correlated with body mass index.

DISCUSSION

This study identified differential impairments underlying IGT performance in AN and BN. Findings suggest that impaired decision making in AN might involve impaired memory functions. Impaired decision making in BN might involve altered reward and punishment sensitivity.

Winning and losing: differences in reward and punishment sensitivity between smokers and nonsmokers

BACKGROUND

Smokers show increased brain activation in reward processing regions in response to smoking-related cues, yet few studies have examined secondary rewards not associated with smoking (i.e., money). Inconsistencies exist in the studies that do examine secondary rewards with some studies showing increased brain activation in reward processing brain regions, while others show decreased activation or no difference in activation between smokers and nonsmokers.

AIMS

The goal of the current study is to see if smokers process the evaluation and delivery of equally salient real world rewards similarly or differently than nonsmokers.

METHODS

The current study employed functional magnetic resonance imaging (fMRI) to examine brain responses in smokers and nonsmokers during the evaluation and delivery of monetary gains and losses.

RESULTS

In comparison to nonsmokers, smokers showed increased activation in the ventromedial prefrontal cortex to the evaluation of anticipated monetary losses and the brain response. Moreover, smokers compared to nonsmokers showed decreased activation in the inferior frontal gyrus to the delivery of expected monetary gains. Brain activations to both the evaluation of anticipated monetary losses and the delivery of expected monetary gains correlated with increased self-reported smoking craving to relieve negative withdrawal symptoms and craving related to positive aspects of smoking, respectively.

DISCUSSION

Together these results indicate that smokers are hyperresponsive to the evaluation of anticipated punishment and hyporesponsive to the delivery of expected rewards. Although further research is needed, this hypersensitivity to punishments coupled with increased craving may negatively impact quit attempts as smokers anticipate the negative withdrawal symptoms associated with quitting.

A narrative review of binge eating and addictive behaviors: shared associations with seasonality and personality factors

Binge-eating disorder and seasonal affective disorder were first described as clinically relevant conditions in very close temporal proximity a few decades ago. Both disorders have a higher prevalence rate in woman than in men, are characterized by a high proneness-to-stress and manifest heightened responsiveness to high-calorie, hyper-palatable foods. In recent years, a compelling body of evidence suggests that foods high in sugar and fat have the potential to alter brain reward circuitry in a manner similar to that seen when addictive drugs like alcohol and heroin are consumed in excess. These findings have led to suggestions that some cases of compulsive overeating may be understood as an addiction to sweet, fatty, and salty foods. In this paper, it is proposed that high seasonality is a risk factor for binge eating, especially in those characterized by anxious and impulsive personality traits - associations that could only occur in an environment with a superfluity of, and easy access to, rich and tasty foods. Given the well-established links between binge eating and addiction disorders [Ref. (1-3) for reviews], it is also suggested that seasonality, together with the same high-risk psychological profile, exacerbates the likelihood of engaging in a broad range of addictive behaviors. Data from a community sample (n = 412) of adults tested these models using linear regression procedures. Results confirmed that symptoms of binge eating and other addictive behaviors were significantly inter-correlated, and that seasonality, gender, and addictive personality traits were strong statistical predictors of the variance in binge-eating scores. Seasonality and addictive personality traits also accounted for a significant proportion of the variance in the measure of addictive behaviors. Conclusions are discussed in the context of brain reward mechanisms, motivational alternations in response to chronic over-consumption, and their relevance for the treatment of excessive appetitive behaviors.

Trajectories of Reinforcement Sensitivity During Adolescence and Risk for Substance Use

Developmental neuroscience models suggest that changes in responsiveness to incentives contribute to increases in adolescent risk behavior, including substance use. Trajectories of sensitivity to reward (SR) and sensitivity to punishment (SP) were examined and tested as predictors of escalation of early substance use in a community sample of adolescents (N=765, mean baseline age 11.8 years, 54% female). SR and SP were assessed using a laboratory task. Across three annual assessments, SR increased, and rapid escalation was associated with increases in substance use. SP declined and was unrelated to substance use. Findings support contemporary views of adolescent brain development, and suggest that early adolescent substance use is motivated by approach responses to reward, rather than failure to avoid potential aversive consequences.

Punishment sensitivity modulates the processing of negative feedback but not error-induced learning

Accumulating evidence suggests that individual differences in punishment and reward sensitivity are associated with functional alterations in neural systems underlying error and feedback processing. In particular, individuals highly sensitive to punishment have been found to be characterized by larger mediofrontal error signals as reflected in the error negativity/error-related negativity (Ne/ERN) and the feedback-related negativity (FRN). By contrast, reward sensitivity has been shown to relate to the error positivity (Pe). Given that Ne/ERN, FRN, and Pe have been functionally linked to flexible behavioral adaptation, the aim of the present research was to examine how these electrophysiological reflections of error and feedback processing vary as a function of punishment and reward sensitivity during reinforcement learning. We applied a probabilistic learning task that involved three different conditions of feedback validity (100%, 80%, and 50%). In contrast to prior studies using response competition tasks, we did not find reliable correlations between punishment sensitivity and the Ne/ERN. Instead, higher punishment sensitivity predicted larger FRN amplitudes, irrespective of feedback validity. Moreover, higher reward sensitivity was associated with a larger Pe. However, only reward sensitivity was related to better overall learning performance and higher post-error accuracy, whereas highly punishment sensitive participants showed impaired learning performance, suggesting that larger negative feedback-related error signals were not beneficial for learning or even reflected maladaptive information processing in these individuals. Thus, although our findings indicate that individual differences in reward and punishment sensitivity are related to electrophysiological correlates of error and feedback processing, we found less evidence for influences of these personality characteristics on the relation between performance monitoring and feedback-based learning.