Ventral striatal and medial prefrontal BOLD activation is correlated with reward-related electrocortical activity: A combined ERP and fMRI study

Psychometric Properties of the Neural Response to Rewards and Errors Across Mid- to Late-Adolescence

Event-related potential (ERP) measures of reward- and error-related brain activity have been used to elucidate neural mechanisms contributing to the development of psychopathology. Adolescence is a critical developmental period that is associated with changes in ERP reward- and error-related brain activity. However, there is a paucity of within-subject research examining whether the reliability of ERP measures is the same or changes across adolescence. Moreover, it is unclear whether the time-frequency representation of reward- and error-related brain activity demonstrates similar psychometric properties. The present study examined the psychometric properties of reward- and error-related brain activity in five hundred and fifty 13.5- to 15.5-year-old (M = 14.4, SD = 0.63) girls. Participants completed the doors and flanker tasks while electroencephalography (EEG) was recorded at two assessments: baseline and 3 years later. Reward- and error-related brain activity were quantified using the time-domain reward positivity (RewP) and error-related negativity (ERN), respectively, as well as time-frequency delta and theta activity. Results indicated that all measures demonstrated adequate split-half reliability at each assessment and 3-year test-retest reliability across assessments. The present study indicates that the psychometric properties of time-domain and time-frequency reward- and error-related brain activity are largely consistent across adolescence, supporting their potential use as individual differences measures of risk for psychopathology.

Exercising self-control increases responsivity to hedonic and eudaimonic rewards

The reward responsivity hypothesis of self-control proposes that irrespective of self-control success, exercising self-control is aversive and engenders negative affect. To countermand this discomfort, reward-seeking behavior may be amplified after bouts of self-control, bringing individuals back to a mildly positive baseline state. Previous studies indicated that effort-an integral component of self-control-can increase reward responsivity. We sought to test and extend the reward responsivity hypothesis by asking if exercising self-control increases a neural marker of reward responsivity [Reward Positivity (RewP)] differentially for hedonic rewards or eudaimonic rewards. We instructed participants (N = 114) to complete a speeded reaction time task where they exercised self-control (incongruent Stroop trials) or not (congruent Stroop trials) and then had the opportunity to win money for themselves (hedonic rewards) or a charity (eudaimonic rewards) while electroencephalography was recorded. Consistent with the reward responsivity hypothesis, participants evinced a larger RewP after exercising self-control (vs. not exercising self-control). Participants also showed a larger RewP for hedonic over eudaimonic rewards. Self-control and reward type did not interactively modulate RewP, suggesting that self-control increases reward responsivity in a domain-general manner. The findings provide a neurophysiological mechanism for the reward responsivity hypothesis of self-control and promise to revitalize the relevant literature.

Reward-Related Brain Activity Mediates the Relationship Between Decision-Making Deficits and Pediatric Depression Symptom Severity

BACKGROUND

The mechanisms that link neural and behavioral indices of reduced reward sensitivity in depression, particularly in children, remain unclear. Reward positivity (RewP), a neural index of reward processing, has been consistently associated with depression. Separately, recent studies using the drift-diffusion model on behavioral data have delineated computational indices of reward sensitivity. Therefore, in the current study, we examined whether RewP is a neural mediator of drift-diffusion model-based indices of reward processing in predicting pediatric depression across varying levels of symptom severity.

METHODS

A community sample of 166 girls, ages 8 to 14 years, completed 2 tasks. The first was a reward guessing task from which RewP was computed using electroencephalography; the second was a probabilistic reward-based decision-making task. On this second task, drift-diffusion model analysis was applied to behavioral data to quantify the efficiency of accumulating reward-related evidence (drift rate) and potential baseline bias (starting point) toward the differently rewarded choices. Depression severity was measured using the self-report Children's Depression Inventory.

RESULTS

RewP was correlated with drift rate, but not starting point bias, toward the more rewarded choice. Furthermore, RewP completely mediated the association between a slower drift rate toward the more rewarded option and higher depression symptom severity.

CONCLUSIONS

Our findings suggest that reduced neural sensitivity to reward feedback may be a neural mechanism that underlies behavioral insensitivity to reward in children and adolescents with higher depression symptom severity, offering novel insights into the relationship between neural and computational indices of reward processing in this context.

The incremental validity of level of personality functioning over borderline personality features in associations with early adolescent social reward processing

More work is needed to establish the validity of the Alternative Model of Personality Disorders (AMPD) in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Acceptance of the AMPD as the primary model of personality disorder requires identifying neurocognitive validators of AMPD-defined personality functioning and demonstrating superiority of the AMPD over the traditional categorical model of personality disorder. It is also important to establish the utility of the AMPD in a developmental context given evidence that personality disorder emerges in adolescence. We assessed the incremental validity of AMPD-defined level of personality functioning (LPF) versus borderline personality features (BPF) in explaining alterations in neural processing of social acceptance feedback in early adolescent girls. One hundred nine girls (Mage = 12.21, SD = 1.21; N = 79 with a psychiatric history) completed a computerized peer interaction task to elicit neural response to social acceptance feedback via electroencephalogram (EEG). Subjects or caregivers reported adolescent psychopathology. In hierarchical regressions controlling for neural response to social rejection and internalizing and externalizing symptoms, LPF incremented BPF and all other covariates in predicting response to social acceptance, but BPF did not. Higher LPF impairment was associated with enhanced reactivity to social acceptance (St.b = 0.274, p = 0.018). LPF appears to provide additional information about neural response to social reward in early adolescence beyond that provided by borderline personality features. These findings add to an emerging literature demonstrating the validity and superiority of the AMPD and help build the rationale for moving toward the AMPD as the primary model of personality disorder classification.

Reward processing dominates the brain during feedback evaluation: Electrophysiological evidence

During reinforcement learning, people learn based on both positive and negative feedback. Researchers have revealed the reward positivity (RewP) that reflects positive feedback evaluation, however, no electrophysiological indicator has been found to explain negative feedback processing. In reinforcement learning, people would like to expect the positive feedback after a choice, which might explain why previous studies usually found neural responses for reward processing, while the negative feedback processing seems absent. However, no study has designed a task to separate positive and negative feedback processing to measure the corresponding electrophysiological responses. Thus, the present study designed gain processing-advantaged (GA) and loss processing-advantaged (LA) contexts using a modified gambling task to measure specific neural responses to gain processing and loss processing. Electroencephalography (EEG) data were processed using time-domain and time-frequency analyses. The results revealed the RewP and delta oscillation following gain feedback in the GA context, while no negativity or other components specific to loss processing was found, even in the loss condition of LA context. The current results indicate that reward processing dominates the brain during feedback evaluation, whereas loss processing can't be captured by electrophysiological signal.

The Impact of Immediate and Delayed Rewards on Task-Switching Performance

BACKGROUND/OBJECTIVES

Switching between different tasks incurs switch costs. Previous research has demonstrated that rewards can enhance performance in cognitive tasks. However, prior studies have primarily focused on the overall improvement in cognitive task performance, with limited research on how different types of rewards function under various task conditions. This study aims to investigate the distinct effects of immediate and delayed rewards on cognitive task performance in different task conditions (repeated trials and task-switching trials) and to explore the underlying neural mechanisms, particularly focusing on how rewards influence attention allocation during the concurrent processing of multiple cues.

METHODS

This study recruited 27 college students (average age 19 years old, 10 males and 17 females). A cue-based task-switching paradigm incorporating immediate and delayed rewards was employed. The study examined the effects of immediate and delayed rewards on cognitive task performance in repeated trials and task-switching trials. Event-related potentials (ERPs) were recorded to investigate the neural mechanisms underlying reward effects on attention allocation.

RESULTS

Behavioral results indicated that immediate rewards significantly enhanced performance in repeated trials compared to delayed rewards. In contrast, no significant difference between immediate and delayed rewards was observed in task-switching trials. ERP results showed that immediate rewards induced a larger P300 amplitude than delayed rewards under the task repetition condition. No P300 difference was found between immediate and delayed rewards under the task-switching condition.

CONCLUSIONS

The findings suggest that rewards enhance task performance by optimizing the allocation of attention to the ongoing task when multiple cues are processed concurrently. When additional resources are required to process task-related cues, there may be insufficient remaining capacity to effectively process reward cues, which could be essential for the optimal completion of the task. These results support the Expected Value of Control (EVC) theory in task-switching scenarios.

Unravelling the origin of reward positivity: a human intracranial event-related brain potential study

Reward positivity (RewP) is an event-related brain potential component that emerges ∼250-350 ms after receiving reward-related feedback stimuli and is believed to be important for reinforcement learning and reward processing. Although numerous localization studies have indicated that the anterior cingulate cortex (ACC) is the neural generator of this component, other studies have identified sources outside of the ACC, fuelling a debate about its origin. Because the results of EEG and magnetoencephalography source-localization studies are severely limited by the inverse problem, we addressed this question by leveraging the high spatial and temporal resolution of intracranial EEG. We predicted that we would identify a neural generator of rthe RewP in the caudal ACC. We recorded intracranial EEG in 19 patients with refractory epilepsy who underwent invasive video-EEG monitoring at Ghent University Hospital, Belgium. Participants engaged in the virtual T-maze task, a trial-and-error task known to elicit a canonical RewP, while scalp and intracranial EEG were recorded simultaneously. The RewP was identified using a difference wave approach for both scalp and intracranial EEG. The data were aggregated across participants to create a virtual 'meta-participant' that contained all the recorded intracranial event-related brain potentials with respect to their intracranial contact locations. We used both hypothesis-driven (focused on ACC) and exploratory (whole-brain analysis) approaches to segment the brain into regions of interest. For each region of interest, we evaluated the degree to which the time course of the absolute current density (ACD) activity mirrored the time course of the RewP, and we confirmed the statistical significance of the results using permutation analysis. The grand average waveform of the scalp data revealed a RewP at 309 ms after reward feedback with a frontocentral scalp distribution, consistent with the identification of this component as the RewP. The meta-participant contained intracranial event-related brain potentials recorded from 582 intracranial contacts in total. The ACD activity of the aggregated intracranial event-related brain potentials was most similar to the RewP in the left caudal ACC, left dorsolateral prefrontal cortex, left frontomedial cortex and left white matter, with the highest score attributed to caudal ACC, as predicted. To our knowledge, this is the first study to use intracranial EEG aggregated across multiple human epilepsy patients and current source density analysis to identify the neural generator(s) of the RewP. These results provide direct evidence that the ACC is a neural generator of the RewP.

Opening the Pandora box: Neural processing of self-relevant negative social information

Curiosity is a powerful motivator of information-seeking behavior. People seek not only positive, but also aversive social information about others. However, whether people also seek unfavorable social information about themselves, as well as the neural mechanisms that may drive such seemingly counterintuitive behavior remain unclear. To address this gap, we developed a novel electroencephalography-compatible Social Incentive Delay (SID) task, which was implemented in 30 healthy young adults as they responded as fast as possible to a target to receive positive or avoid negative comments about their own or about others' Instagram photos. Reaction times were slower for negative vs positive comments' conditions, but only for participants' own photos, revealing less motivation to avoid negative rather than seek positive self-relevant social feedback. Coherently, receiving negative feedback, as opposed to avoiding it, evoked larger amplitudes in the Reward Positivity (RewP) and FB-P3 time-range, especially for participants' own photos, indicating that receiving a negative comment was more rewarding and more salient than not receiving any comment at all. Our findings challenge prior evidence suggesting that humans instinctively avoid aversive stimuli, and they shed light on the neurophysiological mechanisms that may underlie this counterintuitive behavior.

Trimodal brain imaging: A novel approach for simultaneous investigation of human brain function

While advancements have improved the extent to which individual brain imaging approaches capture information regarding spatial or temporal dynamics of brain activity, the connections between these aspects and their relation to psychological functioning remain only partially understood. Acquisition and integration across multiple brain imaging modalities allows for the possible clarification of these connections. The present review provides an overview of three complementary modalities - functional magnetic resonance imaging (fMRI), electroencephalography/event-related potentials (EEG/ERP), and event-related optical signals (EROS) - and discusses progress and considerations for each modality, along with a summary of a novel protocol for acquiring them simultaneously. Initial evidence points to the feasibility of acquiring and integrating multiple measures of brain function that allows for addressing questions in ways not otherwise possible using traditional approaches. Simultaneous trimodal brain imaging in humans provides new possibilities for clarifying spatiotemporal dynamics of brain activity and for identifying multifaceted associations with measures of individual differences and important health outcomes.

Cross-species translational paradigms for assessing positive valence system as defined by the RDoC matrix

Functions associated with processing reward-related information are fundamental drivers of motivation, learning, and goal-directed behavior. Such functions have been classified as the positive valence system under the Research Domain and Criteria (RDoC) criteria and are negatively impacted across a range of psychiatric disorders and mental illnesses. The positive valence system is composed of three comprehensive categories containing related but dissociable functions that are organized into either Reward Responsiveness, Reward Learning, or Reward Valuation. The presence of overlapping behavioral dysfunction across diagnostic mental disorders is in-part what motivated the RDoC initiative, which emphasized that the study of mental illness focus on investigating relevant behavior and cognitive functions and their underlying mechanisms, rather than separating efforts on diagnostic categories (i.e., transdiagnostic). Moreover, the RDoC approach is well-suited for preclinical neuroscience research, as the rise in genetic toolboxes and associated neurotechnologies enables researchers to probe specific cellular targets with high specificity. Thus, there is an opportunity to dissect whether behaviors and cognitive functions are supported by shared or distinct neural mechanisms. For preclinical research to effectively inform our understandings of human behavior however, the cognitive and behavioral paradigms should have predictive, neurobiological, and pharmacological predictive validity to the human test. Touchscreen-based testing systems provide a further advantage for this endeavor enabling tasks to be presented to animals using the same media and task design as in humans. Here, we outline the primary categories of the positive valence system and review the work that has been done cross-species to investigate the neurobiology and neurochemistry underlying reward-related functioning. Additionally, we provide clinical tasks outlined by RDoC, along with validity and/or need for further validation for analogous rodent paradigms with a focus on implementing the touchscreen-based cognitive testing systems.

The Reward Positivity Mediates the Association Between Adverse Childhood Experiences and Anhedonia in Young Adults With Drug-Naïve Major Depressive Disorder

BACKGROUND

Current clinical studies have indicated that major depressive disorder (MDD) concurrent with adverse childhood experiences (ACEs) is associated with greater anhedonia. However, little is known about whether the change in reward sensitivity among young individuals with MDD and ACEs is related to anhedonia.

METHODS

We evaluated anhedonia and ACEs in 86 patients with MDD (31 with no or 1 ACE and 55 with 2 or more ACEs) and 44 healthy control participants. Then, participants completed the Iowa Gambling Task during electroencephalography to measure the reward positivity (RewP) and its difference (ΔRewP; gains minus losses). Furthermore, we constructed a mediation model to assess whether aberrant ΔRewP mediated the relationship between ACEs and anhedonia.

RESULTS

Compared with healthy control participants and MDD patients with no or 1 ACE, MDD patients with 2 or more ACEs had the most severe symptoms of anhedonia and impaired decision making and showed significantly reduced reward sensitivity (most blunted ΔRewP). More importantly, ΔRewP mediated the relationship between ACEs and anhedonia in MDD.

CONCLUSIONS

We found that the ΔRewP partially mediated the association between ACEs and anhedonia in patients with MDD, which provides evidence for the neurobiological basis of abnormal changes in the reward system in MDD individuals with early adverse experiences.

Acute stress-induced reductions in neural response to reward are related to acute stress-related increases in cortisol

Stressors and blunted reward processing are implicated in depression. The current study simultaneously examined the impact of an acute stressor on cortisol and reward processing, measured using the reward positivity (RewP) in 66 participants. Participants completed a reward task during a stressor and a control condition, counterbalanced, and separated by 1 week, while saliva samples were collected before, immediately following, and 25 min after the reward task. Participants reported that the stressor condition was more stressful than the control condition. Cortisol levels did not differ before the reward task; however, cortisol levels were higher both immediately and 25 min after the task. The RewP was blunted during the stressor compared to the control condition, and participants with a larger stress-induced increase in cortisol had greater reductions in their RewP. The current study provides evidence that stress-induced changes in HPA-axis functioning relate to reductions in neural correlates of reward processing.

Characterizing within-person variance in, and menstrual cycle associations with, event-related potentials associated with positive and negative valence systems: The reward positivity and the error-related negativity

Event-related potentials (ERPs) are widely employed as measures of transdiagnostic cognitive processes that are thought to underlie various clinical disorders (Hajcak et al., 2019). Despite their prevalent use as individual difference measures, the effects of within-person processes, such as the human menstrual cycle, on a broad range of ERPs are poorly understood. The present study leveraged a within-subject design to characterize between- and within-person variance in ERPs as well as effects of the menstrual cycle in two frequently studied ERPs associated with positive and negative valence systems underlying psychopathology-the Reward Positivity (RewP) and the Error- Related Negativity (ERN). Seventy-one naturally-cycling participants completed repeated EEG and ecological momentary assessments of positive and negative affect in the menstrual cycle's early follicular, periovulatory, and mid-luteal phases. We examined the mean degree of change between cycle phases in both ERPs, the between-person variability in the degree of change in both ERPs, and whether an individual's degree of cyclical change in these ERPs show coherence with their degree of cyclical change in positive and negative affect recorded across the cycle. Results revealed no significant changes in positive and negative affect across the cycle and rather small changes in ERP amplitudes. Significant random slopes in our model revealed larger individual differences in trajectories of change in ERP amplitudes and affect, in agreement with prior evidence of heterogeneity in dimensional hormone sensitivity. Additionally, state-variance in these ERPs correlated with positive and negative affect changes across the cycle, suggesting that cycle-mediated ERP changes may have relevance for affect and behavior. Finally, exploratory latent class growth mixture modeling revealed subgroups of individuals that display disparate patterns of change in ERPs that should be further investigated.

Neural Reactivity to Social Reward Moderates the Association Between Social Media Use and Momentary Positive Affect in Adolescents

Peer relationships take on increasing importance during adolescence, and there has been considerable debate about the effects of social media use on adolescent emotional health. Little work has examined individual differences in brain function that might impact these associations. In this study, we examined the reward positivity (RewP) to social and monetary reward as a moderator of the relation between social media use and concurrent momentary affect in adolescents. Participants were 145 adolescents aged 14-17 (M = 15.23; SD = 1.08; 64.1% female; 71.7% White) at varying risk for depression (47 high-risk based on maternal depression history, 50 low-risk, 48 currently depressed). Measures of social media use, positive affect (PA), and negative affect (NA) were obtained through ecological momentary assessment. In a laboratory session, adolescents completed a computerized peer feedback task and a monetary reward task to elicit the RewP to social and monetary reward feedback. Multilevel models indicated that social media use and a smaller RewP to monetary rewards were associated with lower PA. However, social (but not monetary) reward responsiveness moderated the effect of social media use on momentary PA, such that social media use was associated with lower PA for adolescents with a relatively blunted RewP to peer acceptance, but not for those with an enhanced social RewP. Exploratory analyses indicated that this moderation effect was specific to female adolescents. The results highlight neural reactivity to social reward as a potential factor contributing to variability in the effect of social media use on affective health.

Multiple risk markers for increases in depression symptoms across two years: Evidence from the reward positivity and the error-related negativity

BACKGROUND

Both a blunted Reward Positivity (RewP) and Error-Related Negativity (ERN) have been associated with depression. Associations between these neural markers and depression have been observed cross-sectionally, but evidence that they can prospectively predict the development of, or increases in, symptoms of depression is more limited.

METHOD

In this study, we collected EEG data from 157 young adults at a baseline visit (T1), using the Doors and Flanker Tasks to elicit the RewP and the ERN respectively. Participants also reported on symptoms of depression at T1, and multiple times across two academic years (T2 - T8).

RESULTS

Using a multilevel model with the RewP and the ERN as predictors, we found that the RewP predicted future symptoms of depression, while controlling for symptoms of depression at T1, such that a blunted RewP at baseline predicted higher depressive symptoms later. In our data, however, the ERN was not a significant predictor of increases in depression symptoms.

CONCLUSIONS

These findings replicate previous work showing the RewP prospectively predicted increases in depression, and further suggest the specificity of this association. Results support the utility of the RewP as a neurophysiological marker that can help clarify the etiology of depression and inform treatment planning.

Linking social reward responsiveness and affective responses to the social environment: An ecological momentary assessment study

Social support is a key predictor of well-being, but not everyone experiences mental health benefits from receiving it. However, given that a growing number of interventions are based on social support, it is crucial to identify the features that make individuals more likely to benefit from social ties. Emerging evidence suggests that neural responses to positive social feedback (i.e., social reward) might relate to individual differences in social functioning, but potential mechanisms linking these neural responses to psychological outcomes are yet unclear. This study examined whether neural correlates of social reward processing, indexed by the reward positivity (RewP), relate to individuals' affective experience following self-reported real-world positive social support events. To this aim, 193 university students (71% females) underwent an EEG assessment during the Island Getaway task and completed a 10-day ecological momentary assessment where participants reported their positive and negative affects (PA, NA) nine times a day and the count of daily positive and negative events. Experiencing a higher number of social support positive events was associated with higher PA. The RewP moderated this association, such that individuals with greater neural response to social feedback at baseline had a stronger positive association between social support positive events count and PA. Individual differences in the RewP to social feedback might be one indicator of the likelihood of experiencing positive affect when receiving social support.

Neural responses to decision-making in suicide attempters with youth major depressive disorder

An improved understanding of the factors associated with suicidal attempts in youth suffering from depression is crucial for the identification and prevention of future suicide risk. However, there is limited understanding of how neural activity is modified during the process of decision-making. Our study aimed to investigate the neural responses in suicide attempters with major depressive disorder (MDD) during decision-making. Electroencephalography (EEG) was recorded from 79 individuals aged 16-25 with MDD, including 39 with past suicide attempts (SA group) and 40 without (NSA group), as well as from 40 age- and sex- matched healthy controls (HCs) during the Iowa Gambling Task (IGT). All participants completed diagnostic interviews, self-report questionnaires. Our study examined feedback processing by measuring the feedback-related negativity (FRN), ΔFN (FRN-loss minus FRN-gain), and the P300 as electrophysiological indicators of feedback evaluation. The SA group showed poorest IGT performance. SA group and NSA group, compared with HC group, exhibited specific deficits in decision-making (i.e., exhibited smaller (i.e., blunted) ΔFN). Post hoc analysis found that the SA group was the least sensitive to gains and the most sensitive to losses. In addition, we also found that the larger the value of ΔFN, the better the decision-making ability and the lower the impulsivity. Our study highlights the link between suicide attempts and impaired decision-making in individuals with major depressive disorder. These findings constitute an important step in gaining a better understanding of the specific reward-related abnormalities that could contribute to the young MDD patients with suicide attempts.

Neural response to monetary and social rewards in adolescent girls and their parents

Functional magnetic resonance imaging (fMRI) studies have indicated that the mesocorticolimbic dopamine system is heavily involved in all stages of reward processing. However, the majority of research has been conducted using monetary rewards and it is unclear to what extent other types of rewards, such as social rewards, evoke similar or different neural activation. There have also been few investigations into potential differences or similarities between reward processing in parents and offspring. The present study examined fMRI neural activation in response to monetary and social reward in a sample of 14-22-year-old adolescent girls (N = 145) and a biological parent (N = 124) and compared activation across adolescent-parent dyads (N = 82). Across all participants, both monetary and social reward elicited bilateral striatal activation, which did not differ between reward types or between adolescents and their parents. Neural activation in response to the different reward types were positively correlated in the striatum among adolescents and in the mPFC and OFC among parents. Overall, the present study suggests that both monetary and social reward elicit striatal activation regardless of age and provides evidence that neural mechanisms underlying reward processing may converge differentially among youth and adults.

Reward positivity affects temporal interval production in a continuous timing task

The neural circuits of reward processing and interval timing (including the perception and production of temporal intervals) are functionally intertwined, suggesting that it might be possible for momentary reward processing to influence subsequent timing behavior. Previous animal and human studies have mainly focused on the effect of reward on interval perception, whereas its impact on interval production is less clear. In this study, we examined whether feedback, as an example of performance-contingent reward, biases interval production. We recorded EEG from 20 participants while they engaged in a continuous drumming task with different realistic tempos (1728 trials per participant). Participants received color-coded feedback after each beat about whether they were correct (on time) or incorrect (early or late). Regression-based EEG analysis was used to unmix the rapid occurrence of a feedback response called the reward positivity (RewP), which is traditionally observed in more slow-paced tasks. Using linear mixed modeling, we found that RewP amplitude predicted timing behavior for the upcoming beat. This performance-biasing effect of the RewP was interpreted as reflecting the impact of fluctuations in reward-related anterior cingulate cortex activity on timing, and the necessity of continuous paradigms to make such observations was highlighted.

Relations Between Neighborhood Disadvantage and Electrocortical Reward Processing in Youth at High and Low Risk for Depression

Neighborhood-level disadvantage during childhood is a determinant of health that is hypothesized to confer risk for psychopathology via alterations in neuro-affective processing, including reward responsiveness. However, little research has examined the impact of socioeconomic disadvantage assessed at the community-level on reward processing, which may have important implications for targeted dissemination efforts. Furthermore, not all youth exposed to neighborhood disadvantage may exhibit alterations in reward reactivity, highlighting the need to consider factors that may exacerbate risk for blunted reward reactivity. The current study examined associations between geocoded indices of neighborhood disadvantage and electrocortical reward responsivity in youth and tested whether findings were moderated by maternal history of depression. The sample included 137 youth recruited for studies on the intergenerational transmission of depression. Neighborhood disadvantage was assessed using the Area Deprivation Index (ADI) while the reward positivity (RewP), an event-related potential, indexed reward response. Results revealed a significant interaction between ADI and maternal history of depression on youth RewP, such that greater neighborhood disadvantage was significantly associated with lower reward responsiveness, but only for youth with a maternal history of depression. Results were maintained controlling for youth internalizing symptoms and individual-level socioeconomic factors. Findings suggest that neighborhood disadvantage may impact youth neural reward processing, at least partially independently of individual risk factors, for youth with a maternal history of depression. If replicated, results suggest intervention efforts may be implemented at the community level to enhance reward responsiveness, specifically for youth living in low-resourced neighborhoods with a maternal history of depression.

Attenuated neural activity in processing decision-making feedback in uncertain conditions in patients with mild cognitive impairment

The present study aimed to explore the potential neural correlates during feedback evaluation during decision-making under risk and ambiguity in MCI. Nineteen individuals with MCI and twenty age-matched HCs were enrolled. Decision-making performance under risk and ambiguity was examined with the modified game of dice task (GDT) and an Iowa gambling task (IGT). Using task-related EEG data, reward positivity (RewP) and feedback P3 (fb-P3) were used to characterize participants' motivation and allocation of cognitive resources. Also, response time and event-related oscillation (ERO) were used to evaluate information processing speed, and the potent of post-feedback information integration and behavioral modulation. MCI patients had lower RewP (p = 0.022) and fb-P3 (p = 0.045) amplitudes in the GDT than HCs. Moreover, the amount and valence of feedback modulated the RewP (p = 0.008; p = 0.017) and fb-P3 (p < 0.001; p < 0.001). In the IGT, in addition to the significantly reduced fb-P3 observed in MCI patients (p = 0.010), the amount and valence of feedback modulated the RewP (p = 0.002; p = 0.020). Furthermore, MCI patients took longer to make decisions (t = 2.15, p = 0.041). The ERO analysis revealed that delta power was reduced in MCI (GDT: p = 0.045; p = 0.011). The findings suggest that, during feedback evaluation when making risky and ambiguous decisions, motivation, allocation of cognitive resources, information processing and neuronal excitability were attenuated in MCI. It implies that neural activity related to decision making was compromised in MCI.

Does effort increase or decrease reward valuation? Considerations from cognitive dissonance theory

The present research tested the effect of manipulated perceived control (over obtaining the outcomes) and effort on reward valuation using the event-related potential known as the Reward Positivity (RewP). This test was conducted in an attempt to integrate two research literatures with opposite findings: Effort justification occurs when high effort leads to high reward valuation, whereas effort discounting occurs when high effort leads to low reward valuation. Based on an examination of past methods used in these literatures, we predicted that perceived control and effort would interactively influence RewP. Consistent with the effort justification literature (cognitive dissonance theory), when individuals have high perceived control, high effort should lead to more reward valuation than low effort should. Consistent with the effort discounting literature, when individuals have low perceived control, low effort should lead to more reward valuation than high effort should. Results supported these interactive and integrative predictions.

Losses disguised as wins evoke the reward positivity event-related potential in a simulated machine gambling task

Electronic gambling machines include a suite of design characteristics that may contribute to gambling-related harms and require more careful attention of regulators and policymakers. One strategy that has contributed to these concerns is the presentation of "losses disguised as wins" (LDWs), a type of salient losing outcome in which a gambling payout is less than the amount wagered (i.e., a net loss), but is nonetheless accompanied by the celebratory audio-visual stimuli that typically accompany a genuine win. These events could thereby be mistaken for gains, or otherwise act as a reward signal, reinforcing persistent gambling, despite being a loss. This study aimed to determine whether LDWs evoke a reward positivity component in a task modeled on slot machine gambling. A prominent account of the reward positivity event-related potential suggests that it is evoked during the positive appraisal of task-related feedback, relative to neutral or negative events, or that it is evoked by neural systems that implement the computation of a positive reward prediction error. We recruited 32 individuals from university recruitment pools and asked them to engage in a simple gambling task designed to mimic key features of a slot machine design. The reward positivity was identified using temporospatial principal components analysis. Results indicated a more positive reward positivity following LDWs relative to clear losses, consistent with the theory that LDWs contribute to positive reinforcement of continued gambling, despite being net losses.

Reduced reward responsiveness and depression vulnerability: Consideration of social contexts and implications for intervention

Depression is a prevalent, heterogeneous, and debilitating disorder that often emerges in adolescence, and there is a need to better understand vulnerability processes to inform more targeted intervention efforts. Psychophysiological methods, like event-related potentials (ERPs), can offer unique insights into the cognitive and emotional processes underlying depression vulnerability. I review my and others' research examining ERP measures of reward responsiveness in youth depression and present a conceptual model of the development of low reward responsiveness, its role in depression vulnerability, and potential windows for targeted intervention. There is evidence that a blunted reward positivity (RewP) is observable in children at risk for depression, appears to be shaped in part by early social experiences, and predicts later depressive symptoms in combination with other risk factors like stress exposure. Further, a component consistent with RewP is reliably elicited in response to social acceptance feedback in computerized peer interaction tasks and demonstrates unique associations with social contextual factors and depressive symptoms, supporting the utility of developing psychophysiological tasks that may better capture youths' real-world experiences and social risk processes. In addition, I address the translational implications of clinical psychophysiological research and describe a series of studies showing that a reduced RewP predicts greater reductions in depressive symptoms with treatment but is not modifiable by current treatments like cognitive behavioral therapy. Finally, I describe our preliminary efforts to develop a positive emotion-focused intervention for the offspring of depressed mothers, informed by the RewP literature, and describe future directions for translating psychophysiological research to intervention and prevention.

Abnormal neural sensitivity to rewards as a candidate process of high depression risk in the FMR1 premutation: A pilot study

The etiological heterogeneity of depression poses a challenge for prevention and intervention efforts. One solution is to map unique etiological pathways for subgroups defined by a singular risk factor. A relevant population for this approach is women who carry the premutation of the fragile X messenger ribonucleoprotein 1 (FMR1) gene, who are at high risk for adult-onset depression. This study explores a candidate neurophysiological marker of depression risk: reduced reward sensitivity, indexed by the reward positivity (RewP). The RewP has been linked to depression risk in the general population, but is unexplored within FMR1 premutation carriers. 16 women with the FMR1 premutation and a matched control group completed a simple guessing task while the electroencephalogram was recorded. Among premutation carriers, RewP difference score (win versus loss) was reduced. These preliminary finding suggest that the FMR1 premutation may confer increased risk for depression in part through abnormal neural sensitivity to rewards.

Mesocorticolimbic system reactivity to alcohol use-related visual cues as a function of alcohol sensitivity phenotype: A pilot fMRI study

Low sensitivity (LS) to alcohol is a risk factor for alcohol use disorder (AUD). Compared to peers with high sensitivity (HS), LS individuals drink more, report more problems, and exhibit potentiated alcohol cue reactivity (ACR). Heightened ACR suggests LS confers AUD risk via incentive sensitization, which is thought to take place in the mesocorticolimbic system. This study examined neural ACR in LS and HS individuals. Young adults (N = 32, M age=20.3) were recruited based on the Alcohol Sensitivity Questionnaire (HS: n = 16; LS: n = 16; 9 females/group). Participants completed an event-related fMRI ACR task. Group LS had higher ACR in left ventrolateral prefrontal cortex than group HS. In group LS, ACR in left caudomedial orbitofrontal cortex or left putamen was low at low alcohol use levels and high at heavier or more problematic alcohol use levels, whereas the opposite was true in group HS. Alcohol use level also was associated with the level of ACR in left substantia nigra among males in group LS. Taken together, results suggest elevated mesocorticolimbic ACR among LS individuals, especially those using alcohol at hazardous levels. Future studies with larger samples are warranted to determine the neurobiological loci underlying LS-based amplified ACR and AUD risk.

Neural response to monetary and social rewards and familial risk for psychopathology in adolescent females

BACKGROUND

Adolescence is a key developmental period for the emergence of psychopathology. Reward-related brain activity increases across adolescence and has been identified as a potential neurobiological mechanism of risk for different forms of psychopathology. The reward positivity (RewP) is an event-related potential component that indexes reward system activation and has been associated with both concurrent and family history of psychopathology. However, it is unclear whether the RewP is also associated with higher-order psychopathology subfactors and whether this relationship is present across different types of reward.

METHODS

In a sample of 193 adolescent females and a biological parent, the present study examined the association between adolescent and parental psychopathology subfactors and adolescent RewP to monetary and social reward.

RESULTS

Results indicated that the adolescent and parental distress subfactors were negatively associated with the adolescent domain-general RewP. The adolescent and parental positive mood subfactors were negatively associated with the adolescent domain-general and domain-specific monetary RewP, respectively. Conversely, the adolescent and parental fear/obsessions subfactors were positively associated with the adolescent domain-general RewP. The associations between parental and adolescent psychopathology subfactors and the adolescent RewP were independent of each other.

CONCLUSIONS

The RewP in adolescent females is associated with both concurrent and parental psychopathology symptoms, suggesting that it indexes both severity and risk for higher-order subfactors.

Machine learning reveals differential effects of depression and anxiety on reward and punishment processing

Recent studies suggest that depression and anxiety are associated with unique aspects of EEG responses to reward and punishment, respectively; also, abnormal responses to punishment in depressed individuals are related to anxiety, the symptoms of which are comorbid with depression. In a non-clinical sample, we aimed to investigate the relationships between reward processing and anxiety, between punishment processing and anxiety, between reward processing and depression, and between punishment processing and depression. Towards this aim, we separated feedback-related brain activity into delta and theta bands to isolate activity that indexes functionally distinct processes. Based on the delta/theta frequency and feedback valence, we then used machine learning (ML) to classify individuals with high severity of depressive symptoms and individuals with high severity of anxiety symptoms versus controls. The significant difference between the depression and control groups was driven mainly by delta activity; there were no differences between reward- and punishment-theta activities. The high severity of anxiety symptoms was marginally more strongly associated with the punishment- than the reward-theta feedback processing. The findings provide new insights into the differences in the impacts of anxiety and depression on reward and punishment processing; our study shows the utility of ML in testing brain-behavior hypotheses and emphasizes the joint effect of theta-RewP/FRN and delta frequency on feedback-related brain activity.

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 = 12.21 years 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 of personality 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.

Reinforcement learning and the reward positivity with aversive outcomes

The reinforcement learning (RL) theory of the reward positivity (RewP), an event-related potential (ERP) component that measures reward responsivity, suggests that the RewP should be largest when positive outcomes are unexpected and has been supported by work using appetitive outcomes (e.g., money). However, the RewP can also be elicited by the absence of aversive outcomes (e.g., shock). The limited work to-date that has manipulated expectancy while using aversive outcomes has not supported the predictions of RL theory. Nonetheless, this work has been difficult to reconcile with the appetitive literature because the RewP was not observed as a reward signal in these studies, which used passive tasks that did not involve participant choice. Here, we tested the predictions of the RL theory by manipulating expectancy in an active/choice-based threat-of-shock doors task that was previously found to elicit the RewP as a reward signal. Moreover, we used principal components analysis to isolate the RewP from overlapping ERP components. Eighty participants viewed pairs of doors surrounded by a red or green border; shock delivery was expected (80%) following red-bordered doors and unexpected (20%) following green-bordered doors. The RewP was observed as a reward signal (i.e., no shock > shock) that was not potentiated for unexpected feedback. In addition, the RewP was larger overall for unexpected (vs expected) feedback. Therefore, the RewP appears to reflect the additive (not interactive) effects of reward and expectancy, challenging the RL theory of the RewP, at least when reward is defined as the absence of an aversive outcome.

Higher-order comparative reward processing is affected by noninvasive stimulation of the ventromedial prefrontal cortex

A crucial skill, especially in rapidly changing environments, is to be able to learn efficiently from prior rewards or losses and apply this acquired knowledge in upcoming situations. Often, we must weigh the risks of different options and decide whether an option is worth the risk or whether we should choose a safer option. The ventromedial prefrontal cortex (vmPFC) is suggested as a major hub for basic but also higher-order reward processing. Dysfunction in this region has been linked to cognitive risk factors for depression and behavioral addictions, including reduced optimism and feedback learning. Here, we test whether modulations of vmPFC excitability via noninvasive transcranial direct current stimulation (tDCS) can alter reward anticipation and reward processing. In a financial gambling task, participants chose between a higher and a lower monetary risk option and eventually received feedback whether they won or lost. Simultaneously feedback on the unchosen option was presented as well. Behavioral and magnetoencephalographic correlates of reward processing were evaluated in direct succession of either excitatory or inhibitory tDCS of the vmPFC. We were able to show modulated reward approach behavior (expectancy of greater reward magnitudes) as well as altered reevaluation of received feedback by vmPFC tDCS as indicated by modified choice behavior following the feedback. Thereby, tDCS not only influenced early, rather basic reward processing, but it also modulated higher-order comparative feedback evaluation of gains and losses relative to alternative outcomes. The neural results underline this idea, as stimulation-driven modulations of the basic reward-related effect occurred at rather early time intervals and were followed by stimulation effects related to comparative reward processing. Importantly, behavioral ratings were correlated with neural activity in left frontal areas. Our results imply a dual function of the vmPFC consisting of approaching reward (as indicated by more risky choices) and elaborately evaluating outcomes. In addition, our data suggest that vmPFC activity is associated with adaptive decision-making in the future via modulated behavioral adaptation or reinforcement learning.

Neural sensitivity following stress predicts anhedonia symptoms: a 2-year multi-wave, longitudinal study

Animal models of depression show that acute stress negatively impacts functioning in neural regions sensitive to reward and punishment, often manifesting as anhedonic behaviors. However, few human studies have probed stress-induced neural activation changes in relation to anhedonia, which is critical for clarifying risk for affective disorders. Participants (N = 85, 12-14 years-old, 53 female), oversampled for risk of depression, were administered clinical assessments and completed an fMRI guessing task during a baseline (no-stress) period to probe neural response to receipt of rewards and losses. After the initial task run of the fMRI guessing task, participants received an acute stressor and then, were re-administered the guessing task. Including baseline, participants provided up to 10 self-report assessments of life stress and symptoms over a 2 year period. Linear mixed-effects models estimated whether change in neural activation (post- vs. pre-acute stressor) moderated the longitudinal associations between life stress and symptoms. Primary analyses indicated that adolescents with stress-related reductions in right ventral striatum response to rewards exhibited stronger longitudinal associations between life stress and anhedonia severity (β = -0.06, 95%CI[-0.11, -0.02], p = 0.008, pFDR = 0.048). Secondary analyses showed that longitudinal positive associations between life stress and depression severity were moderated by stress-related increases in dorsal striatum response to rewards (left caudate β = 0.11, 95%CI[0.07,0.17], p < 0.001, pFDR = 0.002; right caudate β = 0.07, 95%CI[0.02,0.12], p = 0.002, pFDR = 0.003; left putamen β = 0.09, 95%CI[0.04, 0.14], p < 0.001, pFDR = 0.002; right putamen β = 0.08, 95%CI[0.03, 0.12], p < 0.001, pFDR = 0.002). Additionally, longitudinal positive associations among life stress and anxiety severity were moderated by stress-related reductions in dorsal anterior cingulate cortex (β = -0.07, 95%CI[-0.12,.02], p = 0.008, pFDR = 0.012) and right anterior insula (β = -0.07, 95%CI[-0.12,-0.02], p = 0.002, pFDR = 0.006) response to loss. All results held when adjusting for comorbid symptoms. Results show convergence with animal models, highlighting mechanisms that may facilitate stress-induced anhedonia as well as a separable pathway for the emergence of depressive and anxiety symptoms.

Feedback negativity and feedback-related P3 in individuals at risk for depression: Comparing surface potentials and current source densities

Blunted responses to reward feedback have been linked to major depressive disorder (MDD) and depression risk. Using a monetary incentive delay task (win, loss, break-even), we investigated the impact of family risk for depression and lifetime history of MDD and anxiety disorder with 72-channel electroencephalograms (EEG) recorded from 29 high-risk and 32 low-risk individuals (15-58 years, 30 male). Linked-mastoid surface potentials (ERPs) and their corresponding reference-free current source densities (CSDs) were quantified by temporal principal components analysis (PCA). Each PCA solution revealed a midfrontal feedback negativity (FN; peak around 310 ms) and a posterior feedback-P3 (fb-P3; 380 ms) as two distinct reward processing stages. Unbiased permutation tests and multilevel modeling of component scores revealed greater FN to loss than win and neutral for all stratification groups, confirming FN sensitivity to valence. Likewise, all groups had greater fb-P3 to win and loss than neutral, confirming that fb-P3 indexes motivational salience and allocation of attention. By contrast, group effects were subtle, dependent on data transformation (ERP, CSD), and did not confirm reduced FN or fb-P3 for at-risk individuals. Instead, CSD-based fb-P3 was overall reduced in individuals with than without MDD history, whereas ERP-based fb-P3 was greater for high-risk individuals than for low-risk individuals for monetary, but not neutral outcomes. While the present findings do not support blunted reward processing in depression and depression risk, our side-by-side comparison underscores how the EEG reference choice affects the characterization of subtle group differences, strongly advocating the use of reference-free techniques.

Neural response to threat and reward among young adults at risk for alcohol use disorder

Alcohol use disorder (AUD) is heritable. Thus, young adults with positive family histories represent an at-risk group relative to those without a family history, and if studied at a time when both groups have similar levels of alcohol use, it provides an opportunity to identify neural processing patterns associated with risk for AUD. Previous studies have shown that diminished response to potential reward is associated with genetic risk for AUD, but it is unclear how threat may modulate this response. We used a modified Monetary Incentive Delay task during fMRI to examine neural correlates of the interaction between threat and reward anticipation in a sample of young adults with (n = 31) and without (n = 44) family histories of harmful alcohol use. We found an interaction (p = 0.048) between cue and group in the right nucleus accumbens where the family history positive group showed less differentiation to the anticipation of gaining $5 and losing $5 relative to gaining $0. The family history-positive group also reported less excitement for trials to gain $5 relative to gaining $0 (p < 0.001). Family history-positive individuals showed less activation in the left insula during both safe and threat blocks compared to family history-negative individuals (p = 0.005), but the groups did not differ as a function of threat (p > 0.70). Young adults with, relative to without, enriched risk for AUD may have diminished reward processing via both neural and behavioural markers to potential rewarding and negative consequences. Neural response to threat may not be a contributing factor to risk at this stage.

Exploring changes in brain function in IBD patients using SPCCA: a study of simultaneous EEG-fMRI

Research on functional changes in the brain of inflammatory bowel disease (IBD) patients is emerging around the world, which brings new perspectives to medical research. In this paper, the methods of canonical correlation analysis (CCA), kernel canonical correlation analysis (KCCA), and sparsity preserving canonical correlation analysis (SPCCA) were applied to the fusion of simultaneous EEG-fMRI data from 25 IBD patients and 15 healthy individuals. The CCA, KCCA and SPCCA fusion methods were used for data processing to compare the results obtained by the three methods. The results clearly show that there is a significant difference in the activation intensity between IBD and healthy control (HC), not only in the frontal lobe (p < 0.01) and temporal lobe (p < 0.01) regions, but also in the posterior cingulate gyrus (p < 0.01), gyrus rectus (p < 0.01), and amygdala (p < 0.01) regions, which are usually neglected. The mean difference in the SPCCA activation intensity was 60.1. However, the mean difference in activation intensity was only 36.9 and 49.8 by using CCA and KCCA. In addition, the correlation of the relevant components selected during the SPCCA calculation was high, with correlation components of up to 0.955; alternatively, the correlations obtained from CCA and KCCA calculations were only 0.917 and 0.926, respectively. It can be seen that SPCCA is indeed superior to CCA and KCCA in processing high-dimensional multimodal data. This work reveals the process of analyzing the brain activation state in IBD disease, provides a further perspective for the study of brain function, and opens up a new avenue for studying the SPCCA method and the change in the intensity of brain activation in IBD disease.

Neural reward responsiveness and daily positive affect functioning in adolescent girls

Deficits in reward processing have been implicated in the development of many forms of psychopathology, especially major depressive disorder (MDD). One facet of reward processing, known as reward responsivity, has been associated with the development and maintenance of depression across development. The reward positivity (RewP) is an event-related potential derived from electroencephalogram (EEG), which is thought to reflect reward responsivity. An attenuated RewP has been observed in both currently depressed individuals and youth at risk for depression, suggesting it may represent a biomarker of depression. Despite this, little is known about how the RewP translates to behavior and affect in the real world. In the current study, we examined how the RewP relates to real world emotional functioning, measured using ecological momentary assessment (EMA). Thirty-eight female adolescents (ages 11-16, Mage = 13.9 years) participated in the study; approximately half of the sample were considered high risk due to maternal lifetime history of MDD. Adolescents completed a monetary reward task while EEG was recorded, followed by a 10-day period of EMA assessing daily affect and emotion regulation strategy use following positive events. Results revealed that the RewP was positively associated with subjective reports of positive, but not negative, daily affect. Results also revealed that the RewP was positively associated with focusing on positive feelings following a positive event (e.g., savoring). Findings from this preliminary study highlight how neural responses to reward in the lab relate to daily life emotional functioning, supporting the RewP as an ecologically valid marker of positive affect functioning among youth.

Dissociable neural after-effects of cognitive and physical effort expenditure during reward evaluation

The reward after-effect of effort expenditure refers to the phenomenon that previous effort investment changes the subjective value of rewards when obtained. However, the neural mechanisms underlying the after-effects of effort exertion are still not fully understood. We investigated the modulation of reward after-effects by effort type (cognitive vs. physical) through the lens of neural dynamics. Thirty-two participants performed a physically or cognitively demanding task during an effort phase and then played a simple gambling game during a subsequent reward phase to earn monetary rewards while their electroencephalogram (EEG) was recorded. We found that previous effort expenditure decreased electrocortical activity during feedback evaluation. Importantly, this effort effect occurred in a domain-general manner during the early stage (as indexed by the reward positivity) but in a domain-specific manner during the later and more elaborative stage (as indexed by the P3 and delta oscillation) of reward evaluation. Additionally, effort expenditure enhanced P3 sensitivity to feedback valence regardless of effort type. Our findings suggest that cognitive and physical effort, although bearing some surface resemblance to each other, may have dissociable neural influences on the reward after-effects.

Neural response to rewards moderates the within-person association between daily positive events and positive affect during a period of stress exposure

Stress and neural responses to reward can interact to predict psychopathology, but the mechanisms of this interaction are unclear. One possibility is that the strength of neural responses to reward can affect the ability to maintain positive affect during stress. In this study, 105 participants completed a monetary reward task to elicit the reward positivity (RewP), an event-related potential sensitive to rewards. Subsequently, during a stressful period, participants reported on their affect nine times a day and on daily positive and negative events for 10 days. Even during heightened stress, experiencing more positive events was associated with increased positive affect. The RewP significantly moderated this association: Individuals with a larger RewP reported greater increases in positive affect when they experienced more positive events, relative to individuals with a smaller RewP. A blunted RewP might contribute to stress susceptibility by affecting how much individuals engage in positive emotion regulation during stress.

Aberrant dynamic and static functional connectivity of the striatum across specific low-frequency bands in patients with autism spectrum disorder

BACKGROUND

Dysfunctions of the striatum have been repeatedly observed in autism spectrum disorder (ASD). However, previous studies have explored the static functional connectivity (sFC) of the striatum in a single frequency band, ignoring the dynamics and frequency specificity of brain FC. Therefore, we investigated the dynamic FC (dFC) and sFC of the striatum in the slow-4 (0.027-0.073 Hz) and slow-5 (0.01-0.027 Hz) frequency bands.

METHODS

Data of 47 ASD patients and 47 typically developing (TD) controls were obtained from the Autism Brain Imaging Data Exchange (ABIDE) database. A seed-based approach was used to compute the dFC and sFC. Then, a two-sample t-test was performed. For regions showing abnormal sFC and dFC, we performed clinical correlation analysis and constructed support vector machine (SVM) models.

RESULTS

The middle frontal gyrus (MFG), precuneus, and medial superior frontal gyrus (mPFC) showed both dynamic and static alterations. The reduced striatal dFC in the right MFG was associated with autism symptoms. The dynamic‒static FC model had a great performance in ASD classification, with 95.83 % accuracy.

CONCLUSIONS

The striatal dFC and sFC were altered in ASD, which were frequency specific. Examining brain activity using dynamic and static FC provides a comprehensive view of brain activity.

Examining Blunted Initial Response to Reward and Recent Suicidal Ideation in Children and Adolescents Using Event-Related Potentials: Failure to Conceptually Replicate Across Two Independent Samples

A recent study by Tsypes and colleagues (2019) found that children with recent suicidal ideation had blunted neural reward processing, as measured by the reward positivity (RewP), compared to matched controls, and that this difference was driven by reduced neural responses to monetary loss, rather than to reward. Here, we aimed to conceptually replicate and extend these findings in two samples (n = 264, 27 with suicidal ideation; and n = 314, 49 with suicidal ideation at baseline) of children and adolescents (11 to 15 years and 8 to 15 years, respectively). Results from both samples showed no evidence that children and adolescents with suicidal ideation have abnormal reward or loss processing, nor that reward processing predicts suicidal ideation two years later. The results highlight the need for greater statistical power, as well as continued research examining the neural underpinnings of suicidal thoughts and behaviors.

Perceived financial well-being and its association with frontostriatal functional connectivity, real-life anticipatory experiences, and everyday happiness

Perceived financial well-being (FWB) is an important aspect of life that can affect one's attitude toward future experiences and happiness. However, the relationship between FWB, anticipatory experiences, and happiness, and the brain's functional architecture underlying this relationship remain unknown. Here, we combined an experience sampling method, multilevel modeling, and functional neuroimaging to identify the neural correlates of FWB and their associations with real-world anticipatory experiences and everyday happiness. Behaviorally, we found that individuals with greater FWB felt more positive and more interested when they expected positive events to occur, which in turn resulted in increased everyday happiness. Furthermore, the level of FWB was significantly associated with the strength of functional connectivity (FC) between the nucleus accumbens (NAc) and ventromedial prefrontal cortex (vmPFC) and the local coherence within the vmPFC. The frontostriatal FC and local coherence within the vmPFC were further predictive of everyday happiness via the anticipatory response involving interestedness during positive expectations. Our findings suggest that individual differences in FWB could be reflected in the functional architecture of brain's reward system that may contribute to shaping positive anticipatory experiences and happiness in daily life.

Relationship between reward-related brain activity and opportunities to sit

The present study tested whether energy-minimizing behaviors evoke reward-related brain activity that promotes the repetition of these behaviors via reinforcement learning processes. Fifty-eight healthy young adults in a standing position performed a task where they could earn a reward either by sitting down or squatting while undergoing electroencephalographic (EEG) recording. Reward-prediction errors were quantified as the amplitude of the EEG-derived reward positivity. Results showed that reward positivity was larger on reward versus no reward trials, confirming the validity of our paradigm to measure evoked reward-related brain activity. However, results showed no evidence that sitting (versus standing and squatting) trials led to larger reward positivity. Moreover, we found no evidence suggesting that this effect was moderated by typical physical activity, physical activity on the day of the study, or energy expenditure during the experiment. However, at the behavioral level, results showed that the probability of choosing the stimulus more likely to lead to sitting than standing increased as the number of trials increased. In addition, results revealed that the probability of changing the selected stimulus was higher when the previous trial was a stand trial relative to a sit trial. In sum, neural results showed no evidence supporting the theory that opportunities to minimize energy expenditure are rewarding. However, behavioral findings suggested participants tend to choose the less effortful behavioral alternative and were therefore consistent with the theory of effort minimization (TEMPA).

Characterizing positive and negative valence systems function in adolescent depression: An RDoC-informed approach integrating multiple neural measures

Depression is a prevalent, debilitating, and costly disorder that often manifests in adolescence. There is an urgent need to understand core pathophysiological processes for depression to inform more targeted intervention efforts. The Research Domain Criteria (RDoC) Positive Valence Systems (PVS) and Negative Valence Systems (NVS) have both been implicated in depression symptomatology and vulnerability; however, the nature of NVS alterations is unclear across studies, and associations between single neural measures and symptoms are often small in magnitude and inconsistent. The present study advances characterization of depression in adolescence via an innovative data-driven approach to identifying subgroups of PVS and NVS function by integrating multiple neural measures (assessed by electroencephalogram [EEG]) relevant to depression in adolescents oversampled for clinical depression and depression risk based on maternal history (N = 129; 14-17 years old). Results of the k-means cluster analysis supported a two-cluster solution wherein one cluster was characterized by relatively attenuated reward and emotion responsiveness across valences and the other by relatively intact responsiveness. Youth in the attenuated responsiveness cluster reported significantly greater depressive symptoms and were more likely to have major depressive disorder diagnoses than youth in the intact responsiveness cluster. In contrast, associations of individual neural measures with depressive symptoms were non-significant. The present study highlights the importance of innovative neuroscience approaches to characterize emotional processing in depression across domains, which is imperative to advancing the clinical utility of RDoC-informed research.

Aberrant reward dynamics in depression with anticipatory anhedonia

OBJECTIVE

Previous studies have shown that anticipatory anhedonia is linked to abnormal reward processing. The present study aimed to explore the underlying neural mechanism of the influence of anticipatory anhedonia symptoms on reward processing.

METHODS

Electrophysiological activities in the anticipatory and consummatory phase were recorded during the Monetary Incentive Delay (MID) task in 24 depressed high anticipatory anhedonia (HAA) patients, 25 depressed low anticipatory anhedonia (LAA) patients, and 29 healthy controls (HC).

RESULTS

We suggested a significant condition × group interaction effect on feedback-related negativity (FRN) amplitudes during the consummatory phase, a smaller FRN in reward cue trails compared with neutral cue trail was revealed in the HC and LAA group, but such reward-related effect was not found in the HAA group. In addition, we found significant correlations between FRN, fb-P3 and cue-N1, cue-N2 in the HC group, besides, significant correlations between FRN, fb-P3 and cue-P2 was also revealed in the HC and LAA group. However, no significant correlation was found in HAA patients.

CONCLUSIONS

Our results suggest that the link between the anticipatory and consummatory phase was interrupted in depressed HAA patients, which may be driven by the aberrant consummatory reward processing.

SIGNIFICANCE

The current study is the first one to demonstrate the influence of anticipatory anhedonia symptom on the association between anticipatory and consummatory phase of reward process.

Effects of the COVID-19 Pandemic on Neural Responses to Reward: A Quasi-experiment

BACKGROUND

The COVID-19 pandemic has been a prolonged period of stress due to social isolation, illness, death, and other major life disruptions. Neural reward sensitivity, essential for healthy functioning, may become reduced under major naturalistic stressors, though few studies have examined this. The present study sought to test whether neural responses to rewards were significantly blunted by the stress of the pandemic.

METHODS

We compared 2 groups of young adult participants, who completed a monetary reward task while an electroencephalogram was recorded, at 2 time points, 1 to 3 years apart. Our measure of reward sensitivity was the reward positivity (RewP), a neural marker enhanced to gain relative to loss feedback. The magnitude of the RewP is sensitive to stress exposure and can prospectively predict depression. The pre-pandemic group (n = 41) completed both time points before the pandemic, while the pandemic group (n = 39) completed the baseline visit before the pandemic and the follow-up visit during its second year.

RESULTS

The pandemic group reported having experienced significant stressors over the course of the pandemic. We did not observe a significant decrease in the RewP from baseline to follow-up in the pre-pandemic group. In contrast, in the pandemic group, the RewP was significantly blunted at the follow-up visit to the extent that it no longer distinguished gain from loss feedback.

CONCLUSIONS

These results suggest that prolonged naturalistic stressors can result in adaptations in neural responses to rewards. Our findings also highlight a possible mechanism linking stress to the development of depression.

Methamphetamine alters nucleus accumbens neural activation to monetary loss in healthy young adults

RATIONALE

Stimulant drugs like methamphetamine (MA) activate brain reward circuitry, which is linked to the development of problematic drug use. It is not clear how drugs like MA alter neural response to a non-drug reward.

OBJECTIVES

We examined how acute MA impacts neural response to receipt of a monetary reward relative to a loss in healthy adults. We hypothesized that MA (vs. placebo) would increase mesolimbic neural activation to reward, relative to loss.

METHODS

In a within-subject, randomized, cross-over, double-blind, placebo-controlled design, 41 healthy adults completed the Doors monetary reward task during fMRI after ingestion of placebo or 20 mg MA. We examined drug effects on neural response to reward receipt (Win vs. Loss) using a priori anatomical striatal regions of interest (nucleus accumbens (NAcc), caudate, putamen).

RESULTS

MA decreased NAcc BOLD activation to reward vs loss compared to placebo (p=.007) without altering caudate or putamen BOLD activation. Similar effects for reward vs. loss were obtained using whole brain analysis. Additional exploratory ROI analysis comparing reward and loss activation relative to a neutral "fixation" period indicated that MA increased NAcc BOLD activation during loss trials, without decreasing activation during win trials.

CONCLUSIONS

This preliminary evidence suggests that MA increases NAcc neural response to the receipt of monetary loss. Additional studies are needed to replicate our findings and clarify the mechanisms contributing to altered mesolimbic neural response to reward and loss receipt during stimulant intoxication.

Abnormal neurophysiological sensitivity to rewards in depression is moderated by sex and age in middle adulthood

A candidate pathophysiological process in major depressive disorder is diminished neural reactivity to reward delivery, which is theorized to give rise to anhedonia. Reduced amplitude in the reward positivity (RewP), which captures initial reward evaluation, has been linked to current symptoms of depression among child, adolescent, and young adult samples. However, the developmental trajectory of this association is incomplete, with relatively few studies in middle and older adulthood. Further, emerging evidence in the literature also suggests that this association may be linked to female sex-specific processes, but no studies to date have directly contrasted the effect of sex on the depression-RewP association. The current study sought to address these gaps by testing how sex and age may moderate the depression-RewP association within a mature adult community sample. Symptoms of depression were evaluated using a survey and a clinical interview, and the RewP was elicited using a simple guessing task. There was a three-way interaction between depression symptom severity, age, and sex in predicting RewP amplitude. This was driven by younger (late 30's to early 40's) female-sexed people such that for this group, elevated symptoms of depression were associated with blunting of the RewP. This association tapered around age 50. This effect was specific to clinician-rated rather than self-reported depressive symptom severity. This pattern of effects suggests that among female-sexed people, developmental processes continue to shape the association between reward responsiveness and depression throughout middle adulthood.

Non-invasive stimulation reveals ventromedial prefrontal cortex function in reward prediction and reward processing

Introduction

Studies suggest an involvement of the ventromedial prefrontal cortex (vmPFC) in reward prediction and processing, with reward-based learning relying on neural activity in response to unpredicted rewards or non-rewards (reward prediction error, RPE). Here, we investigated the causal role of the vmPFC in reward prediction, processing, and RPE signaling by transiently modulating vmPFC excitability using transcranial Direct Current Stimulation (tDCS).

Methods

Participants received excitatory or inhibitory tDCS of the vmPFC before completing a gambling task, in which cues signaled varying reward probabilities and symbols provided feedback on monetary gain or loss. We collected self-reported and evaluative data on reward prediction and processing. In addition, cue-locked and feedback-locked neural activity via magnetoencephalography (MEG) and pupil diameter using eye-tracking were recorded.

Results

Regarding reward prediction (cue-locked analysis), vmPFC excitation (versus inhibition) resulted in increased prefrontal activation preceding loss predictions, increased pupil dilations, and tentatively more optimistic reward predictions. Regarding reward processing (feedback-locked analysis), vmPFC excitation (versus inhibition) resulted in increased pleasantness, increased vmPFC activation, especially for unpredicted gains (i.e., gain RPEs), decreased perseveration in choice behavior after negative feedback, and increased pupil dilations.

Discussion

Our results support the pivotal role of the vmPFC in reward prediction and processing. Furthermore, they suggest that transient vmPFC excitation via tDCS induces a positive bias into the reward system that leads to enhanced anticipation and appraisal of positive outcomes and improves reward-based learning, as indicated by greater behavioral flexibility after losses and unpredicted outcomes, which can be seen as an improved reaction to the received feedback.

Midfrontal theta as an index of conflict strength in approach-approach vs avoidance-avoidance conflicts

The seminal theory of motivational conflicts distinguishes between approach-approach (AP-AP) conflicts, in which a decision is made between desirable alternatives, and avoidance-avoidance (AV-AV) conflicts, in which a decision is made between undesirable alternatives. The behavioral differences between AP-AP and AV-AV conflicts are well documented: abundant research showed that AV-AV conflicts are more difficult to resolve than AP-AP ones. However, there is little to no research looking into the neural underpinnings of the differences between the two conflict types. Here, we show that midfrontal theta, an established neural marker of conflict, distinguished between the two conflict types such that midfrontal theta power was higher in AV-AV conflicts than in AP-AP conflicts. We further demonstrate that higher midfrontal theta power was associated with shorter decision times on a single-trial basis, indicating that midfrontal theta played a role in promoting successful controlled behavior. Taken together, our results show that AP-AP and AV-AV conflicts are distinguishable on the neural level. The implications of these results go beyond motivational conflicts, as they establish midfrontal theta as a measure of the continuous degree of conflict in subjective decisions.

The longitudinal role of family conflict and neural reward sensitivity in youth's internalizing symptoms

Adolescence is often associated with an increase in psychopathology. Although previous studies have examined how family environments and neural reward sensitivity separately play a role in youth's emotional development, it remains unknown how they interact with each other in predicting youth's internalizing symptoms. Therefore, the current research took a biopsychosocial approach to examine this question using two-wave longitudinal data of 9353 preadolescents (mean age = 9.93 years at T1; 51% boys) from the Adolescent Brain Cognitive Development study. Using mixed-effects models, results showed that higher family conflict predicted youth's increased internalizing symptoms 1 year later, whereas greater ventral striatum (VS) activity during reward receipt predicted reduced internalizing symptoms over time. Importantly, there was an interaction effect between family conflict and VS activity. For youth who showed greater VS activation during reward receipt, high family conflict was more likely to predict increased internalizing symptoms. In contrast, youth with low VS activation during reward receipt showed high levels of internalizing symptoms regardless of family conflict. The findings suggest that youth's neural reward sensitivity is a marker of susceptibility to adverse family environments and highlight the importance of cultivating supportive family environments where youth experience less general conflict within the family.