Patients with Methamphetamine Use Disorder Show Highly Utilized Proactive Inhibitory Control and Intact Reactive Inhibitory Control with Long-Term Abstinence.

Methamphetamine use disorder (MUD) is a chronic brain disorder that involves frequent failures of inhibitory control and relapses into methamphetamine intake. However, it remains unclear whether the impairment of inhibitory control in MUD is proactive, reactive or both. To address this issue, the current study used the conditional stop-signal task to assess proactive and reactive inhibitory control in 35 MUD patients with long-term abstinence and 35 matched healthy controls. The results showed that MUD patients with long-term abstinence had greater preparation costs than healthy controls, but did not differ in performance, implying a less efficient utilization of proactive inhibitory control. In contrast, MUD patients exhibited intact reactive inhibitory control; reactive but not proactive inhibitory control was associated with high sensation seeking in MUD patients with long-term abstinence. These findings suggest that proactive and reactive inhibitory control may be two different important endophenotypes of addiction in MUD patients with long-term abstinence. The current study provides new insight into the uses of proactive and reactive inhibitory control to effectively evaluate and precisely treat MUD patients with long-term abstinence.

Social comparisons differentially affect fair and unfair processing in ultimatum bargaining.

Several theoretical frameworks have attempted to illustrate the influence of social contexts on decision-making and well-being. Traditional economic models assume that absolute income is the crucial determinant of one's well-being, while the comparative models state that social comparisons influence and even determine well-being and decisions. Here we investigated the impact of social comparisons on decision-making using a modified three-player Ultimatum Game and ERP technique. We found two independent effects: First, social comparisons did not affect decision-making when a fair norm was enforced. Second, social comparisons affected fairness consideration for unfair offers only-responders were less likely to accept unfair offers in upward comparisons but more likely to accept unfair offers in downward comparisons. These results revealed that people were envy-free of fair offers while affected mainly by social comparisons when the equality norm was broken. Event-related brain potentials showed that in the early time window (260-320 ms), compared to fair offers, unfair offers elicited a larger negative-going medial frontal negativity (MFN) in upward than parallel and downward comparisons, and in the late stage (320-650 ms), compared to fair offers, unfair offers led to equally less positive-going P300 in upward and downward comparisons relative to parallel comparison. Although partly consistent with the relative standing assumption, both traditional economic models and comparative models require revision to account for the results.

The Impact of Intolerance of Uncertainty on Negative Emotions in COVID-19: Mediation by Pandemic-Focused Time and Moderation by Perceived Efficacy.

The COVID-19 global pandemic has resulted in a large number of people suffering from emotional problems. However, the mechanisms by which intolerance of uncertainty (IU) affects negative emotions during the COVID-19 pandemic remain unclear. This study aimed to explore the mediating role of pandemic-focused time and the moderating role of perceived efficacy in the association between IU and negative emotions during the COVID-19 pandemic based on the uncertainty-time-efficacy-emotion model (UTEE). 1131 participants were recruited to complete measures of COVID-19 IU, pandemic-focused time, perceived efficacy, negative emotions and demographic variables during the COVID-19 pandemic. The results showed that COVID-19 IU was significantly and positively associated with negative emotions, and this link could be mediated by pandemic-focused time. Moreover, the direct effect of COVID-19 IU on negative emotions was moderated by perceived efficacy. Specifically, the direct effect of COVID-19 IU on negative emotions was much stronger for individuals with lower levels of perceived efficacy. The current study further extended the previous integrative uncertainty tolerance model. Furthermore, the study suggested that policy makers and mental health professionals should reduce the general public's negative emotions during the pandemic through effective interventions such as adjusting COVID-19 IU, shortening pandemic-focused time and enhancing perceived efficacy.

Altered Reward Processing System in Internet Gaming Disorder.

Converging evidence indicates that addiction involves impairment in reward processing systems. However, the patterns of dysfunction in different stages of reward processing in internet gaming addiction remain unclear. In previous studies, individuals with internet gaming disorder were found to be impulsive and risk taking, but there is no general consensus on the relation between impulsivity and risk-taking tendencies in these individuals. The current study explored behavioral and electrophysiological responses associated with different stages of reward processing among individuals with internet gaming disorders (IGDs) with a delayed discounting task and simple gambling tasks. Compared to the healthy control (HC) group, the IGD group discounted delays more steeply and made more risky choices, irrespective of the outcome. As for the event-related potential (ERP) results, during the reward anticipation stage, IGDs had the same stimulus-preceding negativity (SPN) for both large and small choices, whereas HCs exhibited a higher SPN in large vs. small choices. During the outcome evaluation stage, IGDs exhibited a blunted feedback-related negativity for losses vs. gains. The results indicate impairment across different stages of reward processing among IGDs. Moreover, we found negative correlation between impulsivity indexed by BIS-11 and reward sensitivity indexed by SPN amplitude during anticipation stage only, indicating different neural mechanisms at different stages of reward processing. The current study helps to elucidate the behavioral and neural mechanisms of reward processing in internet gaming addiction.

Dysfunctional cognitive control and reward processing in adolescents with Internet gaming disorder.

Developmental theories posit that immature cognitive control and excessive reward-seeking capacities may be a risk factor for addictive behaviors during adolescence, but the control and reward capacities have rarely been assessed experimentally in adolescents with Internet gaming disorder (IGD) simultaneously. This electrophysiological study examined inhibitory control and reward processing in adolescents with IGD during a go/no-go task and a gambling task. Behaviorally, the adolescents with IGD exhibited lower inhibitory control, as measured by the accuracy of no-go trials, and more risk seeking, as measured by the proportion of risky choices, than did the controls. Compared with the controls, the adolescents with IGD exhibited decreased no-go P3 and blunted feedback-related negativity (FRN) amplitudes following gains (gain FRN) but not losses. Thus, IGD in adolescents is potentially driven by dysfunction of the control system and the approach system rather than the avoidance system, supporting the neurobiological model of adolescent development.

The Mediating Role of Coping Styles on Impulsivity, Behavioral Inhibition/Approach System, and Internet Addiction in Adolescents From a Gender Perspective.

Previous findings have shown that impulsivity and Behavioral Inhibition/Approach System (BIS/BAS) have substantial effects on adolescents' Internet addiction, but the mechanisms underlying these associations and gender differences in these effects have received little attention. We examined the mediating effects of coping styles from impulsivity, and BIS/BAS to Internet addiction as well as gender differences in these associations. A total of 416 Chinese adolescents were examined using a cross-sectional survey involving Young's Diagnostic Questionnaire for Internet Addiction, Barratt Impulsiveness Scale, BIS/BAS scales, and Coping Style Scale for Middle School Students. The data were analyzed using the independent sample t-test, chi-square test, Pearson correlation, and structure equation modeling. The results from the multiple-group (by adolescent gender) structural model analysis revealed that both impulsivity (p < 0.001) and BIS (p = 0.001) directly predicted positive Internet addiction in girls, while both impulsivity (p = 0.011) and BAS (p = 0.048) directly predicted positive Internet addiction in boys. Furthermore, emotion-focused coping mediated the relationship between impulsivity and Internet addiction (ß = 0.080, 95% CI: 0.023-0.168) and the relationship between BIS and Internet addiction (ß = 0.064, 95% CI: 0.013-0.153) in girls, while in boys, problem-focused coping and emotion-focused coping mediated the association between impulsivity and Internet addiction (ß = 0.118, 95% CI: 0.031-0.251; ß = 0.065, 95% CI: 0.010-0.160, respectively) and problem-focused coping mediated the association between BAS and Internet addiction [ß = -0.058, 95% CI: (-0.142)-(-0.003)]. These findings extend our insight into the mechanisms underlying the associations among impulsivity, BIS/BAS, and Internet addiction in adolescents and suggest that gender-sensitive training approaches to decrease adolescents' Internet addiction are indispensable. These interventions should focus on the different gender predictors of adolescent Internet addiction and on the development of specific coping styles for boys and girls respectively.

Enhanced neural responses to monetary rewards in methamphetamine use disordered individuals compared to healthy controls.

Converging evidence supports that addiction involves the pathological usurpation of normal reward processes. However, the nature and direction of reward processing dysfunction in substance abusers remain unclear. The current study explored the electrophysiological responses associated with different stages of reward processing in methamphetamine (MA) use disordered individuals. Electroencephalography recording was used to compare responses of 21 MA use disordered individuals and 22 healthy controls (HC) while participants engaged in a simple gambling task. Compared to HC, MA use disordered individuals made more risky choices following a loss outcome on a previous trial. During the reward anticipatory stage, MA use disordered individuals showed an enhanced stimulus-preceding negativity (SPN), as compared to HC. During the reward outcome stage, MA use disordered individuals showed an enhanced feedback-related negativity (FRN) for the losses versus gains as compared to HC. Furthermore, an enhanced P300 was observed under the gain condition, but not under the loss condition, in MA use disordered individuals as compared to HC. These findings provide further evidence that MA use disordered individuals have a sensitized neural response to non-drug rewards and support the impulsivity and incentive sensitization theories in MA use disordered individuals. The current study helps to elucidate the neural mechanisms of reward processing in MA use disordered individuals.

Problematic Internet Users Show Impaired Inhibitory Control and Risk Taking with Losses: Evidence from Stop Signal and Mixed Gambles Tasks.

According to the balance model of self-regulation, dysfunction of the inhibitory control and reward processing might be a behavioral marker for addiction and problematic behaviors. Although several studies have separately examined the inhibitory control or reward processing of individuals exhibiting problematic Internet use (PIU), no study has explored these two functions simultaneously to examine the potential imbalance of these functions. This study aimed to investigate whether the self-regulatory failure of PIU individuals results from deficits in both inhibitory control [indexed with the stop signal reaction time (SSRT) in a stop signal task] and risk taking with losses (measured as the acceptance rates of risky gables or the ratio of win/loss in a mixed gambles task). The results revealed that PIU individuals, compared with controls, showed decreased SSRT and increased error rates as well as reduced risk taking with losses. Correlational analyses revealed a significant positive relationship between the SSRT and risk taking with losses. These findings suggest that both the inhibitory control and reward functions are impaired in PIU individuals and reveal an association between these two systems. These results strengthen the balance model of self-regulation theory's argument that deficits in inhibitory control and risk taking with losses may assist in identifying risk markers for early diagnosis, progression, and prediction of PIU.