Monetary Reward Processing Research Articles

Processing abnormalities in monetary outcome evaluations among male individuals with opioid use disorder: evidence from feedback-related negativity

ABSTRACT Background: Numerous studies have highlighted the pivotal role of alterations in the monetary reward system in the development and maintenance of substance use disorder (SUD). Although these alterations have been well documented in various forms of SUD, the electrophysiological mechanisms specific to opioid use disorder (OUD) remain underexplored. Understanding these mechanisms is critical for developing targeted interventions and advancing theories of addiction specific to opioid use. Objectives: To explore abnormalities in monetary reward outcome processing in males with OUD. We hypothesized that control individuals would show higher feedback-related negativity (FRN) to losses, unlike those in the OUD group, where FRN to losses and gains would not differ significantly. Methods: Fifty-seven participants (29 male individuals with OUD [heroin] and 28 male controls) were evaluated. A combination of the monetary incentive delay task (MIDT) and event-related potential (ERP) technology was used to investigate electrophysiological differences in monetary reward feedback processing between the OUD and healthy control groups. Results: We observed a significant interaction between group (control vs. OUD) and monetary outcome (loss vs. gain), indicated by p < .05 and η2 p = 0.116. Specifically, control participants showed stronger negative FRN to losses than gains (p < .05), unlike the OUD group (p > .05). Conclusion: This study’s FRN data indicate that males with OUD show altered processing of monetary rewards, marked by reduced sensitivity to loss. These findings offer electrophysiological insights into why males with OUD may pursue drugs despite potential economic downsides.

Social and Monetary Reward Processing in Youth with Early Emerging Personality Pathology: An RDoC-Informed Study.

Very little is known about the mechanisms underlying the development of personality disorders, hindering efforts to address early risk for these costly and stigmatized disorders. In this study, we examined associations between social and monetary reward processing, measured at the neurophysiological level, and personality pathology, operationalized through the Level of Personality Functioning (LPF), in a sample of early adolescent females (Mage = 12.21years old, SD = 1.21). Female youth with (n = 80) and without (n = 30) a mental health history completed laboratory tasks assessing social and monetary reward responsiveness using electroencephalogram (EEG) and completed ratings ofpersonality pathology. Commonly co-occurring psychopathology, including depression, anxiety, attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD) were also assessed. At the bivariate level, significant associations did not emerge between psychopathology and reward processing variables. When covarying symptoms of depression, anxiety, ADHD, ODD, and CD, an enhanced reward positivity (RewP) component to social reward feedback (accounting for response to social rejection) was associated with higher levels of personality impairment. Results were specific to social rather than monetary reward processing. Depression, anxiety, and ODD also explained unique variance in LPF. These findings suggest that alterations in social reward processing may be a key marker for early emerging personality pathology. Future work examining the role of social reward processing on the development of LPF across adolescence may guide efforts to prevent the profound social dysfunction associated with personality pathology.

Distinct neurofunctional alterations during motivational and hedonic processing of natural and monetary rewards in depression - a neuroimaging meta-analysis.

Reward processing dysfunctions are considered a candidate mechanism underlying anhedonia and apathy in depression. Neuroimaging studies have documented that neurofunctional alterations in mesocorticolimbic circuits may neurally mediate these dysfunctions. However, common and distinct neurofunctional alterations during motivational and hedonic evaluation of monetary and natural rewards in depression have not been systematically examined. Here, we capitalized on pre-registered neuroimaging meta-analyses to (1) establish general reward-related neural alterations in depression, (2) determine common and distinct alterations during the receipt and anticipation of monetary v. natural rewards, and, (3) characterize the differences on the behavioral, network, and molecular level. The pre-registered meta-analysis (https://osf.io/ay3r9) included 633 depressed patients and 644 healthy controls and revealed generally decreased subgenual anterior cingulate cortex and striatal reactivity toward rewards in depression. Subsequent comparative analyses indicated that monetary rewards led to decreased hedonic reactivity in the right ventral caudate while natural rewards led to decreased reactivity in the bilateral putamen in depressed individuals. These regions exhibited distinguishable profiles on the behavioral, network, and molecular level. Further analyses demonstrated that the right thalamus and left putamen showed decreased activation during the anticipation of monetary reward. The present results indicate that distinguishable neurofunctional alterations may neurally mediate reward-processing alterations in depression, in particular, with respect to monetary and natural rewards. Given that natural rewards prevail in everyday life, our findings suggest that reward-type specific interventions are warranted and challenge the generalizability of experimental tasks employing monetary incentives to capture reward dysregulations in everyday life.

Disentangling Brain Network Connectivity During Monetary and Drug-Related Reward Processing in Stimulant Use Disorder

Subglottic stenosis (SGS) is a narrowing of the airway below the vocal cords that can lead to respiratory distress and in severe cases, airway obstruction. Endoscopic surgical management of SGS has been established as a safe and effective treatment option. The aim of this manuscript is to provide an overview of the current state of the art in endoscopic surgical management of SGS. Endoscopic management of SGS typically utilizes laser (CO2 or Nd:YAG) or cold knife incision or wedge excision in combination with rigid or balloon dilation. Topical antifibrotic therapies and steroid injections are frequently employed intraoperatively. The choice of technique depends on the location and severity of the stenosis, and a multimodal approach is common. For patients with extensive stenosis or who have failed previous endoscopic treatments, open surgery may be necessary. Preoperative assessment of the airway is critical for identifying the extent of the stenosis and ensuring appropriate treatment planning. Postoperative care includes close monitoring for complications such as bleeding, infection, and airway edema and adjuvant medical therapies such as proton pump inhibitors, inhaled corticosteroids, and antibiotics are used frequently. In conclusion, endoscopic surgical management of SGS has become an important treatment option for patients with subglottic stenosis, and new techniques such as endoscopic resection with adjuvant medical therapy (ERMT) have been employed effectively in some patients. With proper patient selection, technique selection, and postoperative care, this approach can provide effective relief of symptoms and improve patient outcomes.

Processing of social and monetary rewards in autism spectrum disorders.

Reward processing has been proposed to underpin the atypical social feature of autism spectrum disorder (ASD). However, previous neuroimaging studies have yielded inconsistent results regarding the specificity of atypicalities for social reward processing in ASD. Utilising a large sample, we aimed to assess reward processing in response to reward type (social, monetary) and reward phase (anticipation, delivery) in ASD. Functional magnetic resonance imaging during social and monetary reward anticipation and delivery was performed in 212 individuals with ASD (7.6-30.6 years of age) and 181 typically developing participants (7.6-30.8 years of age). Across social and monetary reward anticipation, whole-brain analyses showed hypoactivation of the right ventral striatum in participants with ASD compared with typically developing participants. Further, region of interest analysis across both reward types yielded ASD-related hypoactivation in both the left and right ventral striatum. Across delivery of social and monetary reward, hyperactivation of the ventral striatum in individuals with ASD did not survive correction for multiple comparisons. Dimensional analyses of autism and attention-deficit hyperactivity disorder (ADHD) scores were not significant. In categorical analyses, post hoc comparisons showed that ASD effects were most pronounced in participants with ASD without co-occurring ADHD. Our results do not support current theories linking atypical social interaction in ASD to specific alterations in social reward processing. Instead, they point towards a generalised hypoactivity of ventral striatum in ASD during anticipation of both social and monetary rewards. We suggest this indicates attenuated reward seeking in ASD independent of social content and that elevated ADHD symptoms may attenuate altered reward seeking in ASD.

Evaluating the neural substrates of effort-expenditure for reward in adults with major depressive disorder and obesity

Converging evidence has suggested that disturbances in monetary reward processing may subserve the shared biosignature between major depressive disorder (MDD) and obesity. However, there remains a paucity of studies that have evaluated the deficits in specific subcomponents of reward functioning in populations with MDD and obesity comorbidity. We evaluated the association between effort-expenditure for monetary reward and neural activation in regions associated with reward-based decision making (i.e., the caudate nucleus, anterior cingulate cortex (ACC) and hippocampus) in people with MDD and obesity comorbidity. We acquired structural and functional magnetic resonance imaging (fMRI) in 12 participants and performed a spherical region-of-interest analysis (ROI) using previously defined peak MNI coordinates. A one-sample t-test was employed to compare ROI-specific blood-oxygen-level-dependent (BOLD) signal change during the task choice selection window (i.e., high-effort vs. low-effort task) of the effort-expenditure for reward task (EEfRT). We observed no change in activation of the caudate nucleus, ACC or hippocampus in participants with increased BMI when contrasting the high effort > low effort reward magnitude condition for the EEfRT. The findings from our exploratory study evaluated the disturbances in fundamental reward processes, including cost-benefit decision making, in people MDD and obesity. Future studies should further investigate this relationship with a larger sample size.

Altered neural reward processing is associated with reward-related decision-making in adolescents with severe obesity

Obesity is associated with altered food-related reward processing, but its impact on non-food reward remains unclear. This question is both timely due to rising rates of severe obesity and important because adolescence is a period of heightened reward seeking behavior. We used computational modeling and functional magnetic resonance imaging (fMRI) to examine monetary reward processing using classic experimental tasks in 35 adolescents (14-18 years-old, 13 male) with severe obesity (OB; n=18) and without obesity (nonOB; n=17). Participants completed the Balloon Analog Risk Taking Task (BART) to assess reward-related decision-making and the Monetary Incentive Delay (MID) task to assess neural correlates of reward anticipation. BART model-based parameters revealed no differences in reward sensitivity but less adaptive decision-making (response consistency) in OB compared to nonOB. Other metrics (e.g., number of balloons popped, number of pumps, and total points) did not differ between groups. During MID reward anticipation, OB had lower activation than nonOB in ventral tegmental area (VTA) and prefrontal cortex, canonical regions for reward and cognitive control, respectively. Weight status moderated associations between VTA activation and BART metrics such that higher VTA activation was associated with more risky decision-making (more popped balloons) in OB but not nonOB. Functional connectivity of VTA with right inferior frontal gyrus (IFG) and left superior temporal gyrus (STG) was greater higher in OB than nonOB. Associations between value-related VTA-STG connectivity and BART metrics were moderated by weight status such that higher connectivity was associated with greater number of pumps and points for nonOB and less risky decision-making for OB. Therefore, differences in activation and connectivity between groups may suggest differences in decision-making strategies. Together, findings reveal that VTA, prefrontal, and temporal engagement during monetary reward anticipation differs in OB and nonOB adolescents and may contribute to individual differences in reward-related decision-making. Such domain-general alteration of reward processing may have far reaching consequences, not only for food intake but also functions central to motivational behavior such as learning and socialization during adolescence, a sensitive period in development. These findings highlight the importance of considering reward more broadly when designing and tailoring behavioral interventions in adolescent obesity

Effective connectivity of the amygdala during the consumption of erotic, sexual humor, and monetary rewards with a DCM-PEB approach.

While a large body of research exists on the processing of monetary rewards, less is known about sexual reward processing. This study aimed to identify effective connectivity for the consumption of sexual (erotic and sexual humor) and non-sexual (monetary) rewards, using dynamic causal modeling and parametric empirical Bayes with subjective hedonic ratings included. Our results support the importance of the amygdala for sexual humor amusement, the nucleus accumbens (NAc) for monetary rewards, and the lateral orbitofrontal cortex (lOFC) for erotic pleasure. The amygdala, NAc, and lOFC are major dopaminergic targets with known roles in the reward circuitry. Appreciating sexual humor was associated with ventral tegmental area (VTA) to amygdala connectivity. Enjoying monetary gains was associated with VTA-to-NAc and amygdala-to-NAc connectivity. The mesolimbic dopamine system originates in the VTA and sends major projections to the amygdala and NAc. Specifically, sexual humor appreciation was associated with effective connectivity from the ventromedial prefrontal cortex (vmPFC) to the amygdala, suggesting that subjective pleasure triggers activation of the vmPFC which exerts an excitatory influence on the amygdala. Unexpectedly, processing pleasure from monetary gains was linked to VTA-to-vmPFC connectivity, rather than the expected vmPFC-to-NAc connectivity. Importantly, we identified core roles for the amygdala. Sexual humor appreciation was associated with VTA-to-amygdala and vmPFC-to-amygdala effective connectivity, while we found amygdala-to-lOFC connectivity for erotic pleasure and amygdala-to-NAc connectivity for pleasure from monetary gains. Our findings represent an important step in understanding how effective connectivity in the mesocorticolimbic-amygdala circuitry differs for processing the consumption of sexual and monetary rewards.

Understanding the neurobiological basis of anhedonia in major depressive disorder - evidence for reduced neural activation during reward and loss processing.

Background:Anhedonia is a key symptom of major depressive disorder (MDD). Anhedonia is associated with aberrant reward processing, but whether it might interfere similarly with the neural processing of aversive stimuli, such as monetary loss, remains unknown. We aimed to investigate potential associations between anhedonia and neural response during reward and loss processing in patients with MDD.Methods:We investigated blood-oxygen-level-dependent response in the orbitofrontal cortex, cingulate cortex, insula and basal ganglia during monetary reward and loss processing in 182 patients with MDD, using a card-guessing paradigm. We measured anhedonia with the Social and Physical Anhedonia Scale (SASPAS), and we tested for the main and interaction effects of SASPAS scores and the experimental condition (reward or loss) in a full factorial model.Results:We detected a negative main effect of anhedonia, as well as a significant interaction effect of anhedonia and the experimental condition, on orbitofrontal and insular neural response. Post hoc analyses revealed that the interaction was driven by a significant association between higher anhedonia scores and hypoactivation during loss processing. We observed no significant association between anhedonia and neural response during reward processing.Limitations:This study had a cross-sectional design.Conclusion:Our findings confirmed that altered neural processing in the orbitofrontal cortex and insula is a neurobiological feature of anhedonic symptomatology in people with MDD. The pronounced association between anhedonia and blunted neural response during loss processing supports a broader concept for the neurobiological basis of anhedonia. Hence, MDD with anhedonic features might be characterized by reduced neural response to external stimuli, potentially because of amotivation.

Associations between parental conflict and social and monetary reward responsiveness in adolescents with clinical depression.

Increased rates of depression beginning in adolescence are thought to be attributed in part to marked developmental changes in reward systems and interpersonal relationships. Blunted reward response has been observed in depression and this may be shaped in part by social experiences, raising questions about the combined associations of parental conflict, depression, and reward response in both social and monetary domains. The present study used the reward positivity (RewP), an event-related potential that indexes both monetary and social reward processing, to examine the unique and combined associations of parental conflict and depressive symptoms on reward responsiveness in adolescents with clinical depression (N = 70) 14-18 years of age (M = 15.81, SD = 1.46; 65.7% female). Results indicated that depressive symptoms interacted with maternal conflict in characterizing the RewP to social, but not monetary, rewards. Specifically, higher levels of current depressive symptoms and potentiated maternal conflict together were associated with an attenuated RewP to social rewards in this clinical sample. We found no significant effects of paternal conflict. This investigation highlights maternal conflict as an important environmental factor for reward responsiveness and also emphasizes the utility of examining social reward responsiveness in depression in order to better understand the impacts of contextual factors.

Social exclusion modulates neural dynamics of monetary and social reward processing in young adult females

Evidence suggests that social exclusion increases one’s sensitivity to monetary and social rewards. However, whether and how social exclusion modulates the neural dynamics of reward processing remains unknown. The current study aimed to address this gap by systematically investigating the differential influences of social exclusion on various stages of monetary and social reward processing. Forty-five female participants were recruited, and the Cyberball game was used to manipulate social exclusion. To disentangle the anticipatory and consummatory stages of monetary and social reward processing, we recorded event-related potentials during two incentive delay tasks, one with a monetary reward and one with a social reward. The results showed that during the anticipatory stage, a larger contingent negative variation was observed for the exclusion group than for the inclusion group, regardless of reward type. During the consummatory stage, although the reward-related positivity was larger in the exclusion group than in the inclusion group, this difference was only observed for the social, and not monetary, reward feedback. These findings advance our understanding of the relationship between social exclusion and reward processing and suggest that while social exclusion might exert comparable enhancement effect for monetary and social reward processing during the anticipatory stage, it exerts a specific enhancement effect for social reward processing during the consummatory stage.

Effects of retrieval-extinction training on internet gaming disorder.

Background and aimsInternet gaming disorder (IGD) leads to serious impairments in cognitive functions, and lacks of effective treatments. Cue-induced craving is a hallmark feature of this disease and is associated with addictive memory elements. Memory retrieval-extinction manipulations could interfere with addictive memories and attenuate addictive syndromes, which might be a promising intervention for IGD. The aims of this study were to explore the effect of a memory retrieval-extinction manipulation on gaming cue-induced craving and reward processing in individuals with IGD.MethodsA total of 49 individuals (mean age: 20.52 ± 1.58) with IGD underwent a memory retrieval-extinction training (RET) with a 10-min interval (R-10min-E, n = 24) or a RET with a 6-h interval (R-6h-E, n = 25) for two consecutive days. We assessed cue-induced craving pre- and post-RET, and at the 1- and 3-month follow-ups. The neural activities during reward processing were also assessed pre- and post-RET.ResultsCompared with the R-6h-E group, gaming cravings in individuals with IGD were significantly reduced after R-10min-E training at the 3-month follow-up (P < 0.05). Moreover, neural activities in the individuals with IGD were also altered after R-10min-E training, which was corroborated by enhanced reward processing, such as faster responses (P < 0.05) and stronger frontoparietal functional connectivity to monetary reward cues, while the R-6h-E training had no effects.Discussion and ConclusionsThe two-day R-10min-E training reduced addicts’ craving for Internet games, restored monetary reward processing in IGD individuals, and maintained long-term efficacy.

Size of Social Network and Strength of Working Alliance Predict Perceived Valence of Social Rewards during Psychotherapy for Late-life Depression

<h3>Introduction</h3> Processing of monetary and social rewards is inhibited in late-life depression¹. Social isolation predicts depression severity² and poor response to psychotherapy.³ Individuals with smaller social networks are more socially isolated and experience fewer socially rewarding interactions. Engagement in socially rewarding experiences predicts reduction in depression in psychotherapy for late-life depression.⁴ In psychotherapy, a positive therapist-patient relationship may enhance the experience of social rewards, and in turn lead to better outcomes. This study aimed to investigate whether the size of social network and the quality of the working alliance predict perceived valence of social rewards during psychotherapy. Our group developed a novel social reward task that measures response to social rewards during psychotherapy. We hypothesized that individuals with a larger social network and a stronger therapeutic alliance would demonstrate higher perceived social reward valence of feedback from their therapist. <h3>Methods</h3> Forty-five older adults with major depression (75.56% female; mean age = 69.44, SD = 9.60) participated in two randomized controlled psychotherapy trials for late-life depression. Participants received 9 weeks of either psychoeducation, Supportive Therapy, or "Engage" behavioral activation therapy⁵. Inclusion criteria included a primary diagnosis of major depression as determined by the SCID DSM-V and a depression severity score of ³20 on the Montgomery Asberg Depression Rating Scale (MADRS). At weeks 0, 3, 5, and 9, we measured the strength of working alliance with the Working Alliance Inventory (WAI) and the size of social network with the Social Network subscale of the Duke Social Support Index (DSSI). Perceived valence of social rewards was measured at weeks 0, 5, and 9 using our novel Social Task for Assessment of Reward (STAR), where participants received either positive or negative feedback from their therapist or an unfamiliar person and then rated the valence of the social feedback they received. We used mixed effects regression models, with fixed effect for the predictor (alliance or social network), time*predictor interaction, and random intercept for participant, to test whether social factors predicted participants' rated valence of the social reward feedback they received during the task. <h3>Results</h3> We found that a stronger working alliance predicted higher perceived valence of positive feedback from the therapist, <i>F</i>(1, 60.81) = 7.99, <i>p</i> = .006. We also found a significant interaction effect between size of the social network and time predicting perceived valence of positive feedback from the therapist, <i>F</i>(2, 17.98) = 5.06, <i>p</i> = .018. A larger social network predicted higher perceived valence of the feedback, and post-hoc analyses showed that this relationship increased over the course of the interventions. No significant effects were found for the feedback from the unfamiliar person. <h3>Conclusions</h3> Social factors – a strong working alliance and a larger social network – contribute to increased perceived value of positive feedback from a therapist and that this association increases during treatment. The strength of working alliance and size of social network were not associated with feedback from an unfamiliar person, suggesting that the working relationship with the therapist may serve as a socially rewarding experience. Our results underscore the importance of assessing social isolation as it may predict individuals' experience of socially rewarding interactions. Interventions could focus on increasing social rewards during psychotherapy by expanding patients' social networks and building a positive alliance. Future studies will focus on investigating the association between social factors, the perceived valence of social rewards, and treatment outcome. <h3>This research was funded by</h3> This study was funded by the National Institutes of Mental Health grants K23MH123864 and K23MH116105.

Substance Abuse in Emerging Adults: The Role of Neuromelanin and Ventral Striatal Response to Social and Monetary Rewards.

Perturbations in dopamine system function may increase risk of substance use disorder (SUD). We recently demonstrated that neuromelanin (NM) MRI signal in the substantia nigra, a non-invasive index of dopamine system function, is elevated in long term cocaine users (Cassidy et al., 2020). However, it is unclear whether elevated NM-MRI signal is linked to risk of SUD, or is a byproduct of long-term drug use. Our prior work failed to show relations between NM-MRI signal and functional engagement of ventral striatum during a monetary reward task. However, social experiences are commonly linked to drug use and relapse. Given that, NM-MRI signal may be more closely linked to ventral striatal engagement during social, rather than monetary reward processing. Emerging adults (n = 33, 21.88 ± 4.35 years) with varying levels of substance abuse, but without SUD, underwent NM-MRI and fMRI during social and monetary reward processing tasks. Voxelwise analysis within the substantia nigra (SN) demonstrated lower NM-MRI signal was associated with more severe substance abuse. Lower right ventral striatal engagement to social reward was also associated with more severe substance abuse. This relation was moderated by SN NM-MRI signal such that diminished striatal response to reward was associated with greater substance abuse among those with low NM-MRI signal, but lower substance abuse among those with high NM-MRI signal. Unexpectedly, higher right ventral striatal engagement during monetary reward was associated with more severe substance abuse. This relation was moderated by SN NM-MRI signal such that greater striatal response to reward was associated with greater substance abuse among those with low NM-MRI signal. Taken together, we provide preliminary evidence that, in emerging adults, low rather than high dopamine system function may increase risk of substance abuse, and strengthen the association between substance use and the brain’s sensitivity to social and monetary outcomes in different ways.

Integrated Amygdala, Orbitofrontal and Hippocampal Contributions to Reward and Loss Coding Revealed with Human Intracranial EEG.

Neurophysiological work in primates and rodents have shown the amygdala plays a central role in reward processing through connectivity with the orbitofrontal cortex (OFC) and hippocampus. However, understanding the role of oscillations in each region and their connectivity in different stages of reward processing in humans has been hampered by limitations with noninvasive methods such as poor spatial and temporal resolution. To overcome these limitations, we recorded local field potentials (LFPs) directly from the amygdala, OFC and hippocampus simultaneously in human male and female epilepsy patients performing a monetary incentive delay (MID) task. This allowed us to dissociate electrophysiological activity and connectivity patterns related to the anticipation and receipt of rewards and losses in real time. Anticipation of reward increased high-frequency gamma (HFG; 60-250 Hz) activity in the hippocampus and theta band (4-8 Hz) synchronization between amygdala and OFC, suggesting roles in memory and motivation. During receipt, HFG in the amygdala was involved in outcome value coding, the OFC cue context-specific outcome value comparison and the hippocampus reward coding. Receipt of loss decreased amygdala-hippocampus theta and increased amygdala-OFC HFG amplitude coupling which coincided with subsequent adjustments in behavior. Increased HFG synchronization between the amygdala and hippocampus during reward receipt suggested encoding of reward information into memory for reinstatement during anticipation. These findings extend what is known about the primate brain to humans, showing key spectrotemporal coding and communication dynamics for reward and punishment related processes which could serve as more precise targets for neuromodulation to establish causality and potential therapeutic applications.SIGNIFICANCE STATEMENT Dysfunctional reward processing contributes to many psychiatric disorders. Neurophysiological work in primates has shown the amygdala, orbitofrontal cortex (OFC), and hippocampus play a synergistic role in reward processing. However, because of limitations with noninvasive imaging, it is unclear whether the same interactions occur in humans and what oscillatory mechanisms underpin them. We addressed this issue by recording local field potentials (LFPs) from all three regions in human epilepsy patients during monetary reward processing. There was increased amygdala-OFC high-frequency coupling when losing money which coincided with subsequent adjustments in behavior. In contrast, increased amygdala-hippocampus high-frequency phase-locking suggested a role in reward memory. The findings highlight amygdala networks for reward and punishment processes that could act as more precise neuromodulation targets to treat psychiatric disorders.

Who initiates punishment, who joins punishment? Disentangling types of third-party punishers by neural traits.

The act of punishing unfair behavior by unaffected observers (i.e., third‐party punishment) is a crucial factor in the functioning of human societies. In everyday life, we see different types of individuals who punish. While some individuals initiate costly punishment against an unfair person independently of what other observers do (independent punishers), others condition their punishment engagement on the presence of another person who punishes (conditional punishers). Still others do not want to partake in any sort of punishment (nonpunishers). Although these distinct behavioral types have a divergent impact on human society, the sources of heterogeneity are poorly understood. We present novel laboratory evidence on the existence of these three types. We use anatomical brain characteristics in combination with stated motives to characterize these types. Findings revealed that independent punishers have larger gray matter volume in the right temporo‐parietal junction compared to conditional punishers and nonpunishers, an area involved in social cognition. Conditional punishers are characterized by larger gray matter volume in the right dorsolateral prefrontal cortex, a brain area known to be involved in behavioral control and strategic reasoning, compared to independent punishers and nonpunishers. Finally, both independent punishers and nonpunishers are characterized by larger gray matter volume in an area involved in the processing of social and monetary rewards, that is, the bilateral caudate. By using a neural trait approach, we were able to differentiate these three types clearly based on their neural signatures, allowing us to shed light on the underlying psychological mechanisms.

Social Exclusion Modulates Neural Dynamics of Monetary and Social Reward Processing

Social Exclusion Modulates Neural Dynamics of Monetary and Social Reward Processing

Functional dynamics of dopamine synthesis during monetary reward and punishment processing

The assessment of dopamine release with the PET competition model is thoroughly validated but entails disadvantages for the investigation of cognitive processes. We introduce a novel approach incorporating 6-[18F]FDOPA uptake as index of the dynamic regulation of dopamine synthesis enzymes by neuronal firing. The feasibility of this approach is demonstrated by assessing widely described sex differences in dopamine neurotransmission. Reward processing was behaviorally investigated in 36 healthy participants, of whom 16 completed fPET and fMRI during the monetary incentive delay task. A single 50 min fPET acquisition with 6-[18F]FDOPA served to quantify task-specific changes in dopamine synthesis. In men monetary gain induced stronger increases in ventral striatum dopamine synthesis than loss. Interestingly, the opposite effect was discovered in women. These changes were further associated with reward (men) and punishment sensitivity (women). As expected, fMRI showed robust task-specific neuronal activation but no sex difference. Our findings provide a neurobiological basis for known behavioral sex differences in reward and punishment processing, with important implications in psychiatric disorders showing sex-specific prevalence, altered reward processing and dopamine signaling. The high temporal resolution and magnitude of task-specific changes make fPET a promising tool to investigate functional neurotransmitter dynamics during cognitive processing and in brain disorders.

Differentiating the abnormalities of social and monetary reward processing associated with depressive symptoms.

Reward dysfunction is a major dimension of depressive symptomatology, but it remains obscure if that dysfunction varies across different reward types. In this study, we focus on the abnormalities in anticipatory/consummatory processing of monetary and social reward associated with depressive symptoms. Forty participants with depressive symptoms and forty normal controls completed the monetary incentive delay (MID) and social incentive delay (SID) tasks with event-related potential (ERP) recording. In the SID but not the MID task, both the behavioral hit rate and the ERP component contingent negative variation (CNV; indicating reward anticipation) were sensitive to the interaction between the grouping factor and reward magnitude; that is, the depressive group showed a lower hit rate and a smaller CNV to large-magnitude (but not small-magnitude) social reward cues compared to the control group. Further, these two indexes were correlated with each other. Meanwhile, the ERP components feedback-related negativity and P3 (indicating reward consumption) were sensitive to the main effect of depression across the MID and SID tasks, though this effect was more prominent in the SID task. Overall, we suggest that depressive symptoms are associated with deficits in both the reward anticipation and reward consumption stages, particularly for social rewards. These findings have a potential to characterize the profile of functional impairment that comprises and maintains depression.

Neural dynamics of monetary and social reward processing in social anhedonia.

Being characterized by reduced pleasure from social interaction, social anhedonia constitutes a transdiagnostic marker for various psychiatric disorders. However, the neural portrait of social anhedonia remains elusive because of heterogeneities of reward type and reward dynamics in previous studies. The present event-related potential study investigated neural dynamics in response to monetary and social rewards in social anhedonia. Event-related potential responses were examined when a high social anhedonia (HSA, N = 23) group and a low social anhedonia (LSA, N = 26) group were anticipating and consuming social and monetary rewards. LSA but not HSA participants showed an increased stimulus-preceding negativity (anticipatory phase) and and increased reward positivity (consummatory phase) for monetary as compared with social rewards. This group difference could spring from an increased relevance of social rewards or a general decline in affective responding due to a potential association between social anhedonia and depression. Our findings provide preliminary evidence for neural aberrations of the reward system in social anhedonia, which is contingent upon reward type and reward dynamics.