Cognitive control and reward/loss processing in Internet gaming disorder: Results from a comparison with recreational Internet game-users

Meta-analysis of structural and functional abnormalities in behavioral addictions

BACKGROUND

The incidence of behavioral addictions (BAs) associated with scientific and technological advances has been increasing steadily. Unfortunately, a large number of studies on the structural and functional abnormalities have shown poor reproducibility, and it remains unclear whether different addictive behaviors share common underlying abnormalities. Therefore, our objective was to conduct a quantitative meta-analysis of different behavioral addictions to provide evidence-based evidence of common structural and functional changes.

METHODS

We conducted systematic searches in PubMed, Web of Science and Scopus from January 2010 to December 2023, supplementing reference lists of high-quality relevant meta-analyses and reviews, to identify eligible voxel-based morphometry (VBM) and functional magnetic resonance imaging (fMRI) studies. Using anisotropic seed-based D-Mapping (AES-SDM) meta-analysis methods, we compared brain abnormalities between BAs and healthy controls (HCs).

RESULTS

There were 11 GMV studies (287 BAs and 292 HCs) and 26 fMRI studies (577 BAs and 545 HCs) that met inclusion criteria. Compared with HCs, BAs demonstrated significant reductions in gray matter volume (GMV) in (1) right anterior cingulate gyri extending into the adjacent superior frontal gyrus, as well as in the left inferior frontal gyrus and right striatum. (2) the bilateral precuneus, right supramarginal gyrus, and right fusiform gyrus were hyperfunction; (3) the left medial cingulate gyrus extended to the superior frontal gyrus, the left inferior frontal gyrus, and right middle temporal gyrus had hypofunction.

CONCLUSIONS

Our study identified structural and functional impairments in brain regions involved in executive control, cognitive function, visual memory, and reward-driven behavior in BAs. Notably, fronto-cingulate regions may serve as common biomarkers of BAs.

Understanding the relationships among adolescents' internet dependence, reward, cognitive control processing, and learning burnout: a network perspective in China

Alterations in the reward and cognitive control systems are commonly observed among adolescents with internet dependence (ID), and this impairment is often accompanied by social dysfunctions, such as academic burnout. However, the intercorrelations among ID, reward, cognitive control processing, and learning burnout remain unclear. We recruited 1074 Chinese adolescents to investigate the complex interrelationships among these variables using network analysis. The resulting network revealed patterns that connected ID to the behavioral inhibition/activation system (BIS/BAS), self-control, and learning burnout; these results exhibited reasonable stability and test-retest consistency. Throughout the network, the node of BAS-drive was the critical influencing factor, and the node of self-control was the protection factor. In addition, several symptoms of learning burnout and ID were positively associated with sensitivity to punishment. As revealed by the network comparison test, the network constructed among internet dependent (ID) group differed from the network constructed among internet nondependent (IND) group not only in the edges between BIS and learning burnout but also in terms of the edges associated with learning burnout. In conclusion, this study provides insights into the complex mechanisms underlying ID among adolescents from the perspective of the network relationships between core influencing factors and negative consequences. It validates the dual-system model of risky behavior among adolescents and offers a foundation for early warning and interventions for ID in this context.

Adolescent Internet Gaming Disorder and sensitivity to money and social rewards

Internet Gaming Disorder (IGD) is a behavioural addiction characterised by excessive exposure to addictive stimuli, resulting in reduced sensitivity of the brain's reward system towards everyday rewards. Online game addiction is prevalent among adolescents; however, it remains unclear if there are variations in reward processing patterns among adolescents with online game addiction. We compared differences in sensitivity to two types of rewards between patients with IGD and patients with Recreational Game Use (RGU) using the Monetary Incentive Delay (MID) paradigm and the Social Incentive Delay (SID) paradigm (Experiment 1). Additionally, we used a mixed reward latency paradigm, including both monetary and social rewards, to further explore the processing characteristics of IGD towards a mixture of these two rewards (Experiment 2). There were significant differences in the sensitivity of IGD and RGU to monetary and social rewards. Adolescents with IGD had significantly shorter reaction times to the four mixed rewards compared to RGU, while no significant differences were found between groups regarding sensitivity to specific individual rewards. However, the simultaneous presence of two rewards affected the processing speed and preference of adolescents with IGD. The reward processing characteristics observed in adolescents with online gaming disorder show specificity concerning the type and presentation of rewards, providing a theoretical foundation for diagnosing and treating adolescent online gaming addiction.

Outcome assessment of different reward stimuli in Internet gaming disorder by event-related potentials

An imbalance in sensitivity to different types of reward stimuli may be an important cause of addiction that is mainly manifested in high sensitivity to addictive substance rewards and blunting of natural rewards. However, contradictions remain in the research results on the sensitivity of individuals with Internet gaming disorder (IGD) to different reward stimuli. Based on participants' neural responses to win and loss feedback (in door task), the event-related potential (ERP) technique was used to investigate the effects of different types of reward stimuli on the assessment of reward-processing outcomes in individuals with IGD. The results showed that in the gain condition, the FB-P3 amplitude induced by game stimuli in the IGD group was significantly higher than that in the control group, and the FN amplitude induced by money stimuli was significantly lower than that in the control group. However, the FB-P3 and FN amplitudes induced by food were not significantly different from those in the control group. In the loss condition, there were no between-group differences in the FB-P3 and FN amplitudes evoked by the three reward stimuli. This indicates that the IGD group showed increased hedonic responses to game stimuli and decreased hedonic responses to money but no differences in hedonic responses to food during the reward assessment phase. Therefore, heightened sensitivity to game rewards and diminished sensitivity to monetary rewards during outcome assessment may play a crucial role in the development of IGD.

Mobile phone short video use negatively impacts attention functions: an EEG study

The pervasive nature of short-form video platforms has seamlessly integrated into daily routines, yet it is important to recognize their potential adverse effects on both physical and mental health. Prior research has identified a detrimental impact of excessive short-form video consumption on attentional behavior, but the underlying neural mechanisms remain unexplored. In the current study, we aimed to investigate the effect of short-form video use on attentional functions, measured through the attention network test (ANT). A total of 48 participants, consisting of 35 females and 13 males, with a mean age of 21.8 years, were recruited. The mobile phone short video addiction tendency questionnaire (MPSVATQ) and self-control scale (SCS) were conducted to assess the short video usage behavior and self-control ability. Electroencephalogram (EEG) data were recorded during the completion of the ANT task. The correlation analysis showed a significant negative relationship between MPSVATQ and theta power index reflecting the executive control in the prefrontal region (r = -0.395, p = 0.007), this result was not observed by using theta power index of the resting-state EEG data. Furthermore, a significant negative correlation was identified between MPSVATQ and SCS outcomes (r = -0.320, p = 0.026). These results suggest that an increased tendency toward mobile phone short video addiction could negatively impact self-control and diminish executive control within the realm of attentional functions. This study sheds light on the adverse consequences stemming from short video consumption and underscores the importance of developing interventions to mitigate short video addiction.

Navigating Exploitative Traps: Unveiling the Uncontrollable Reward Seeking of Individuals With Internet Gaming Disorder

BACKGROUND

Internet gaming disorder (IGD) involves an imbalance in the brain's dual system, characterized by heightened reward seeking and diminished cognitive control, which lead to decision-making challenges. The exploration-exploitation strategy is key to decision making, but how IGD affects this process is unclear.

METHODS

To investigate the impact of IGD on decision making, a modified version of the 2-armed bandit task was employed. Participants included 41 individuals with IGD and 44 healthy control individuals. The study assessed the strategies used by participants in the task, particularly focusing on the exploitation-exploration strategy. Additionally, functional magnetic resonance imaging was used to examine brain activation patterns during decision-making and estimation phases.

RESULTS

The study found that individuals with IGD demonstrated greater reliance on exploitative strategies in decision making due to their elevated value-seeking tendencies and decreased cognitive control. Individuals with IGD also displayed heightened activation in the presupplementary motor area and the ventral striatum compared with the healthy control group in both decision-making and estimation phases. Meanwhile, the prefrontal cortex showed more inhibition in individuals with IGD than in the healthy control group during exploitative strategies. This inhibition decreased as cognitive control diminished.

CONCLUSIONS

The imbalance in the development of the dual system in individuals with IGD may lead to an overreliance on exploitative strategies. This imbalance, marked by increased reward seeking and reduced cognitive control, contributes to difficulties in decision making and value-related behavioral processes in individuals with IGD.

Efficacy and Neural Mechanisms of Mindfulness Meditation Among Adults With Internet Gaming Disorder: A Randomized Clinical Trial

Importance

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), recently identified internet gaming disorder (IGD) as a condition warranting more research, and few empirically validated treatments exist. Mindfulness meditation (MM) has multiple health benefits; however, its efficacy in treating IGD and potential neural mechanisms underlying MM treatment of the disorder remain largely unknown.

Objective

To explore the efficacy of MM used to treat adults with IGD and to identify neural mechanisms underlying MM.

Design, Setting, and Participants

This randomized clinical trial was performed from October 1 to November 30, 2023, at Hangzhou Normal University in Hangzhou, China. Adults (aged ≥18 years) who met at least 6 of the 9 DSM-5-TR proposed criteria for IGD were recruited to receive either MM or progressive muscle relaxation (PMR). Data analysis was performed on December 1, 2023.

Intervention

Participants underwent MM training (an 8-session meditation program that focuses on attention and acceptance) and PMR training (an 8-time program for body relaxation) delivered in groups that met 2 times each week for 4 weeks.

Main Outcomes and Measures

This per-protocol analysis included only participants who finished the pretest assessment, 8 training sessions, and posttest assessment. The main outcomes were addiction severity (measured with the DSM-5-TR proposed criteria for IGD and with Internet Addiction Test scores), gaming craving (measured with Questionnaire for Gaming Urges scores), and blood oxygen level-dependent signals assessed with cue-craving tasks on fMRI. Behavioral and brain measurements were compared using analysis of variance. Functional connectivity (FC) among identified brain regions was measured to test connectivity changes associated with MM.

Results

This study included 64 adults with IGD. A total of 32 participants received MM (mean [SD] age, 20.3 [1.9] years; 17 women [53%]) and 32 received PMR (mean [SD] age, 20.2 [1.5] years; 16 women [50%]). The severity of IGD decreased in the MM group (pretest vs posttest: mean [SD], 7.0 [1.1] vs 3.6 [0.8]; P < .001) and in the PMR group (mean [SD], 7.1 [0.9] vs 6.0 [0.9]; P = .04). The MM group had a greater decrease in IGD severity than the PMR group (mean [SD] score change for the MM group vs the PMR group, -3.6 [0.3] vs -1.1 [0.2]; P < .001). Mindfulness meditation was associated with decreased brain activation in the bilateral lentiform nuclei (r = 0.40; 95% CI, 0.19 to 0.60; P = .02), insula (r = 0.35; 95% CI, 0.09 to 0.60; P = .047), and medial frontal gyrus (MFG; r = 0.43; 95% CI, 0.16 to 0.70; P = .01). Increased MFG-lentiform FC and decreased craving (pretest vs posttest: mean [SD], 58.8 [15.7] vs 33.6 [12.0]; t = -8.66; ƞ2 = 0.30; P < .001) was observed after MM, and changes in MFG-lentiform FC mediated the relationship between increased mindfulness and decreased craving (mediate effect, -0.17; 95% CI, -0.32 to -0.08; P = .03).

Conclusions and Relevance

In this study, MM was more effective in decreasing addiction severity and gaming cravings compared with PMR. These findings indicate that MM may be an effective treatment for IGD and may exert its effects by altering frontopallidal pathways.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2300075869.

Effects of Game-Related Tasks for the Diagnosis and Classification of Gaming Disorder

Gaming disorder (GD) is an addictive behavior characterized by an insatiable need to play video games and shares similar symptoms with the failure of self-control due to a decline in cognitive function. Current GD diagnostic and screening tools rely on questionnaires and behavioral observations related to cognitive functions to assess an individual's capacity to maintain self-control in everyday life. However, current GD screening approaches rely on subjective symptoms, and a reliable diagnosis requires long-term clinical follow-up. Recent studies have measured biosignals along with cognitive functional tasks to provide objectivity to GD diagnosis and to acquire immediate results. However, people with GD are hypersensitive to game-related cues, so their responses may vary depending on the type of stimuli, and the difference in response to stimuli might manifest as a difference in the degree of change in the biosignal. Therefore, it is critical to choose the correct stimulus type when performing GD diagnostic tasks. In this study, we investigated the task dependence of cognitive decline in GD by comparing two cognitive functional tasks: a continuous performance task (CPT) and video game play. For this study, 69 young male adults were classified into either the gaming disorder group (GD, n = 39) or a healthy control group (HC, n = 30). CPT score, EEG signal (theta, alpha, and beta), and HRV-HF power were assessed. We observed differences in the left frontal region (LF) of the brain between the GD and HC groups during online video game play. The GD group also showed a significant difference in HF power of HRV between CPT and online video gaming. Furthermore, LF and HRV-HF significantly correlated with Young's Internet Addiction Test (Y-IAT) score, which is positively associated with impulsivity score. The amount of change in theta band activity in LF and HRV-HF-both biomarkers for changes in cognitive function-during online video game play suggests that people with GD express task-dependent cognitive decline compared with HC. Our results demonstrate the feasibility of quantifying individual self-regulation ability for gaming and underscore its importance for GD classification.

The severity of addiction mediates loneliness and cortical volume in internet gaming disorder

Internet gaming disorder (IGD) subjects reported higher loneliness scores than healthy controls. However, the neural correlates underlying the association between loneliness and IGD remain unclear. Thus, the aim of this study was to explore the relationship between loneliness, online gaming addiction and brain structure. In the current study, structural MRI data were acquired from 84 IGD subjects and 103 matched recreational game users (RGUs). We assessed and compared their addiction severity, loneliness scores, and cortical volumes and analyzed the correlations among these values. Significant correlations were found between loneliness scores and brain volumes in the postcentral cortex, the medial orbitofrontal cortex, the rostral anterior cingulate cortex, and the temporal cortex. In addition, the addiction severity scores partly mediated the relationship between loneliness score and cortical volume in IGD. The results showed that participants with extreme loneliness had significant correlations with brain regions responsible for executive control, social threat surveillance and avoidance. More importantly, the severity of addiction mediates loneliness and cortical volume. The findings shed new insight into the neural mechanisms of loneliness and IGD and have implications for potential treatment.

Neural mechanisms linked to treatment outcomes and recovery in substance-related and addictive disorders

The present review focuses on potential neural mechanisms underlying recovery from psychiatric conditions characterised by impaired impulse control, specifically substance use disorders, gambling disorder, and internet gaming disorder. Existing treatments (both pharmacological and psychological) for these addictions may impact brain processes, and these have been evaluated in neuroimaging studies. Medication challenge and short-term intervention administration will be considered with respect to treatment utility. Main models of addiction (e.g., dual process, reward deficiency syndrome) will be considered in the context of extant data. Additionally, advanced analytic approaches (e.g., machine-learning approaches) will be considered with respect to guiding treatment development efforts. Thus, this narrative review aims to provide directions for treatment development for addictive disorders.

Neuropsychological Deficits in Disordered Screen Use Behaviours: A Systematic Review and Meta-analysis

Over the last few decades, excessive and disordered screen use has become more prevalent, prompting investigations into its associated consequences. The extent to which disordered screen use behaviours impact neuropsychological functioning has been reportedly mixed and at times inconsistent. This review sought to synthesise the literature and estimate the magnitude of overall cognitive impairment across a wide range of disordered screen use behaviours. We also sought to determine the cognitive domains most impacted, and whether the observed impairments were moderated by the classification of screen-related behaviours (i.e., Internet or gaming) or the format of cognitive test administration (i.e., paper-and-pencil or computerised). A systematic search of databases (Embase, PsycINFO, MEDLINE) identified 43 cross-sectional articles that assessed neuropsychological performance in disordered screen use populations, 34 of which were included in the meta-analysis. A random-effects meta-analysis revealed significant small/medium (g = .38) cognitive deficits for individuals with disordered screen use behaviours relative to controls. The most affected cognitive domain with a significant medium effect size (g = .50) was attention and focus followed by a significant reduction in executive functioning (g = .31). The classification of disordered screen use behaviours into Internet or gaming categories or the format of cognitive testing did not moderate these deficits. Additionally, excluding disordered social media use in an exploratory analysis had little effect on the observed outcomes. This study highlights a number of methodological considerations that may have contributed to disparate findings and shows that disordered screen use can significantly impact cognitive performance. Recommendations for future research are also discussed. Data for this study can be found at https://osf.io/upeha/ .

Disrupted dynamic network reconfiguration of the executive and reward networks in internet gaming disorder

BACKGROUND

Studies have shown that people with internet gaming disorder (IGD) exhibit impaired executive control of gaming cravings; however, the neural mechanisms underlying this process remain unknown. In addition, these conclusions were based on the hypothesis that brain networks are temporally static, neglecting dynamic changes in cognitive processes.

METHODS

Resting-state fMRI data were collected from 402 subjects [162 subjects with IGD and 240 recreational game users (RGUs)]. The community structure (recruitment and integration) of the executive control network (ECN) and the basal ganglia network (BGN), which represents the reward network, of patients with IGD and RGUs were compared. Mediation effects among the different networks were analyzed.

RESULTS

Compared to RGUs, subjects with IGD had a lower recruitment coefficient within the right ECN. Further analysis showed that only male subjects had a lower recruitment coefficient. Mediation analysis showed that the integration coefficient of the right ECN mediated the relationship between the recruitment coefficients of both the right ECN and the BGN in RGUs.

CONCLUSIONS

Male subjects with IGD had a lower recruitment coefficient than RGUs, which impairing their impulse control. The mediation results suggest that top-down executive control of the ECN is absent in subjects with IGD. Together, these findings could explain why subjects with IGD exhibit impaired executive control of gaming cravings; these results have important therapeutic implications for developing effective interventions for IGD.

Effects of Transcranial Electrical Stimulation on Gambling and Gaming: A Systematic Review of Studies on Healthy Controls, Participants with Gambling/Gaming Disorder, and Substance Use Disorder

Gambling disorder (GD) and internet gaming disorder (IGD) are formally recognized behavioral addictions with a rapidly growing prevalence and limited treatment options. Recently, transcranial electrical stimulation (tES) techniques have emerged as potentially promising interventions for improving treatment outcomes by ameliorating cognitive functions implicated in addictive behaviors. To systematize the current state of evidence and better understand whether and how tES can influence gambling and gaming-related cognitive processes, we conducted a PRISMA-guided systematic review of the literature, focusing on tES effects on gaming and gambling in a diverse range of population samples, including healthy participants, participants with GD and IGD, as well as participants with substance abuse addictions. Following the literature search in three bibliographic databases (PubMed, Web of Science, and Scopus), 40 publications were included in this review, with 26 conducted on healthy participants, 6 focusing on GD and IGD patients, and 8 including participants with other addictions. Most of the studies targeted the dorsolateral prefrontal cortex, using transcranial direct current stimulation (tDCS), and assessed the effects on cognition, using gaming and gambling computerized cognitive tasks measuring risk taking and decision making, e.g., balloon analogue risk task, Iowa gambling task, Cambridge gambling task, etc. The results indicated that tES could change gambling and gaming task performances and positively influence GD and IGD symptoms, with 70% of studies showing neuromodulatory effects. However, the results varied considerably depending on the stimulation parameters, sample characteristics, as well as outcome measures used. We discuss the sources of this variability and provide further directions for the use of tES in the context of GD and IGD treatment.

Deficient dynamics of prefrontal-striatal and striatal-default mode network (DMN) neural circuits in internet gaming disorder

BACKGROUND

Studies have proven that individuals with internet gaming disorder (IGD) show impaired cognitive control over game craving; however, the neural mechanism underlying this process remains unclear. Accordingly, the present study aimed to investigate the dynamic features of brain functional networks of individuals with IGD during rest, which have barely been understood until now.

METHODS

Resting-state fMRI data were collected from 333 subjects (123 subjects with IGD (males/females: 73/50) and 210 healthy controls (males/females: 135/75)). First, the data-driven methodology, named co-activation pattern analysis, was applied to investigate the dynamic features of nucleus accumbens (the core region involved in craving/reward processing and addiction)-centered brain networks in IGD. Further, machine learning analysis was conducted to investigate the prediction effect of the dynamic features on participants' addiction severity.

RESULTS

Compared to controls, subjects in the IGD group showed decreased resilience, betweenness centrality and occurrence in the prefrontal-striatal neural circuit, and decreased in-degree in the striatal-default mode network (DMN) circuit. Moreover, these decreased dynamic features could significantly predict participants' addiction severity.

LIMITATIONS

The causal relationship between IGD and the abnormal dynamic features cannot be identified in this study. All the subjects were university students.

CONCLUSIONS

The present results revealed the underlying brain networks of uncontrollable craving and game-seeking behaviors in individuals with IGD during rest. The decreased dynamics of the prefrontal-striatal and striatal-DMN neural circuits might be potential biomarkers for predicting the addiction severity of IGD and potential targets for effective interventions to reduce game craving of this disorder.

Influences of Emotional Information on Response Inhibition in Gaming Disorder: Behavioral and ERP Evidence from Go/Nogo Task

BACKGROUND

Gaming disorder (GD) may impair executive functions such as response inhibition. According to the tripartite neurocognitive model, the interoceptive system generates a state of craving that exacerbates the dysfunction of GD. We speculate that emotional information may play an important role in the mechanism, which leads to impaired response inhibition in people with GD.

METHODS

A three-factor mixed experimental design was adopted in this go/nogo task. The between-subject factor was group (GD or control group), and the within-subject factors were two types of emotional information, task relevance (related or unrelated) and emotional valence (negative or positive).

RESULTS

The GD group had lower nogo accuracies than the control group in the task-unrelated condition and also in the negative condition. Parallelly, the GD group showed faster reactions and lower accuracy in the go trials than the control group under task-unrelated negative conditions. At the neural level, the GD group had smaller amplitudes of nogo-N2 and larger amplitudes of nogo-P3 than the control group in the task-unrelated condition.

CONCLUSIONS

The findings prove the hypothesis of this study that emotional information could be a factor leading to impaired response inhibition in GD individuals. The response inhibition abilities of GD are weakened when processing task-unrelated or negative information, which may be caused by failure of behavioral inhibition and weakened conflict control, resulting in more cognitive resources to complete response suppression under specific conditions. This study provides evidence for weaker response inhibition in GD individuals from the perspective of cognitive-emotional interaction and provides more detailed information for interventions for GD.

Predicting the severity of internet gaming disorder with resting-state brain features: A multi-voxel pattern analysis

BACKGROUND

Internet gaming disorder (IGD) has become a worldwide mental health concern; however, the neural mechanism underlying this disorder remains unclear. Multivoxel pattern analysis (MVPA), a newly developed data-driven approach, can be used to investigate the neural features of IGD based on massive neural data.

METHODS

Resting-state fMRI data from four hundred and two participants with varying levels of IGD severity were recruited. Regional homogeneity (ReHo) and the amplitude of low-frequency fluctuation (ALFF) were calculated and subsequently decoded by applying MVPA. The highly weighted regions in both predictive models were selected as regions of interest for further graph theory and Granger causality analysis (GCA) to explore how they affect IGD severity.

RESULTS

The results revealed that the neural patterns of ReHo and ALFF can independently and significantly predict IGD severity. The highly weighted regions that contributed to both predictive models were the right precentral gyrus and left postcentral gyrus. Moreover, topological properties of the right precentral gyrus were significantly correlated with IGD severity; further GCA revealed effective connectivity from the right precentral gyrus to left precentral gyrus and dorsal anterior cingulate cortex, both of which were significantly associated with IGD severity.

CONCLUSIONS

The present study demonstrated that IGD has distinctive neural patterns, and this pattern could be found by machine learning. In addition, the neural features in the right precentral gyrus play a key role in predicting IGD severity. The current study revealed the neural features of IGD and provided a potential target for IGD interventions using brain modulation.

Sex differences in neural substrates of risk taking: Implications for sex-specific vulnerabilities to internet gaming disorder

BACKGROUND AND AIMS

Sex differences in internet gaming disorder (IGD) remain unknown. Investigating sex-specific neural features that underlie the core risk factor (i.e., risk-taking) of IGD would help in understanding sex-specific vulnerabilities to IGD and advance sex-specific treatments and prevention for IGD.

METHODS

111 participants (28 IGD males, 27 IGD females, 26 recreational game user (RGU) males, 30 RGU females) completed a probability discounting task during fMRI scanning.

RESULTS

First, among RGUs, males showed a higher risk-taking tendency and greater neural activation associated with risk/value evaluation for reward (the ventromedial prefrontal cortex (vmPFC), anterior cingulate cortex (ACC), left putamen) and smaller activation associated with cognitive control (the inferior frontal gyrus) than females during the contrast of risky-safe choices. Moreover, males showed a greater modulatory effect of risky choices on the connection from the vmPFC/ACC to the left putamen than females. Second, IGD males showed decreased activation in the vmPFC/ACC and left putamen compared to RGU males, whereas this decrease did not exist in IGD females.

DISCUSSION

Males show a higher risk-taking tendency than females. Altered neural substrates associated with risky decision-making exist in IGD males but not in IGD females.

CONCLUSIONS

The present findings fill the gap in information on the behavioral and neural substrates underlying IGD among females and demonstrate that a high risk-taking tendency is a risk factor and core symptom only in IGD males but not in IGD females. It is necessary to design and adopt distinct treatments and prevention strategies for IGD in males and females.

Meta-analysis of structural and functional brain alterations in internet gaming disorder

Background

Many neuroimaging studies have reported abnormalities in brain structure and function in internet gaming disorder (IGD). However, the findings were divergent. We aimed to provide evidence-based evidence of structural and functional changes in IGD by conducting a meta-analysis integrating these studies quantitatively.

Method

A systematic search was conducted in PubMed, ScienceDirect, Web of Science, and Scopus from January 1, 2010 to October 31, 2021, to identify eligible voxel-based morphometry (VBM) and functional magnetic resonance imaging (fMRI) studies. Brain alternations between IGD subjects and healthy controls (HCs) were compared using the anisotropic seed-based d mapping (AES-SDM) meta-analytic method. Meta-regression analysis was used to investigate the relationship between gray matter volume (GMV) alterations and addiction-related clinical features.

Results

The meta-analysis contained 15 VBM studies (422 IGD patients and 354 HCs) and 30 task-state fMRI studies (617 IGD patients and 550 HCs). Compared with HCs, IGD subjects showed: (1) reduced GMV in the bilateral anterior/median cingulate cortex, superior/inferior frontal gyrus and supplementary motor area; (2) hyperactivation in the bilateral inferior frontal gyrus, precentral gyrus, left precuneus, right inferior temporal gyrus and right fusiform; (3) hypoactivation in the bilateral lingual and the left middle frontal gyrus; and (4) both decreased GMV and increased activation in the left anterior cingulate. Furthermore, Meta-regression revealed that GMV reduction in left anterior cingulate were positively correlated with BIS-11 score [r = 0.725, p = 0.012(uncorrected)] and IAT score [r = 0.761, p = 0.017(uncorrected)].

Conclusion

This meta-analysis showed structural and functional impairments in brain regions related to executive control, cognitive function and reward-based decision making in IGD. Furthermore, multi-domain assessments captured different aspects of neuronal changes in IGD, which may help develop effective interventions as potential therapeutic targets.

Diminished cognitive control in Internet gaming disorder: A multimodal approach with magnetic resonance imaging and real-time heart rate variability

OBJECTIVE

Recently, the addiction to online games, classified as Internet gaming disorder (IGD) on DSM-V, has emerged as an important mental health problem. The loss of control over gaming in IGD is associated with diminished cognitive control. This study aimed to link the neurobiological mechanism reflected by brain imaging and the diminished cognitive control reflected by heart rate variability (HRV) measurements during real-time gameplay.

METHODS

HRV was assessed in 33 young males with IGD and 29 controls while playing their favorite games. Seed-based functional connectivity (FC) was evaluated in the dorsolateral prefrontal cortex, anterior cingulate cortex, and dorsal striatum. Associations between HRV and alterations in FC were tested.

RESULTS

Individuals with IGD showed a reduction of high-frequency HRV during real-time gaming, which is correlated with self-reported severity of IGD. Subjects with IGD showed decreased FC between the right dorsolateral prefrontal cortex and the right inferior frontal gyrus, corresponding to the cognitive control network. They showed decreased FC between the right anterior cingulate cortex and the superior parietal lobule. They also showed increased FC between the left dorsal putamen and the postcentral gyrus, corresponding to the sensorimotor network. Game-related high-frequency HRV was correlated with dorsolateral prefrontal cortex-inferior frontal gyrus connectivity.

CONCLUSION

The diminished cognitive control reflected by HRV measurements during real-time gameplay was associated with FC alterations, involving a weak FC in the cognitive control network. Individuals with IGD may have less cognitive control, particularly when playing games, and consequently end up playing games in a habitual manner rather than in a goal-oriented manner.

Profile of Treatment-Seeking Gaming Disorder Patients: A Network Perspective

The increasing presence of gaming disorder in recent years has led to major efforts to identify the specific predictors that have a high impact on the profile of people seeking treatment for this mental condition. The purpose of this study was to explore the network structure of the correlates of gaming disorder considering sociodemographic features and other clinical symptoms. Network analysis was applied to a sample of patients who met clinical criteria for gaming disorder (n = 117, of ages ranging from 15 to 70 yrs-old). Variables considered in the network included sex, age, socioeconomic position, global emotional distress, age of onset and duration of the gaming disorder, personality traits and the presence of other addictive behaviors (tobacco, alcohol and behavioral addictions). The central nodes in the network were global psychological distress, chronological age, and age of onset of gaming related problems. Linkage analysis also identified psychopathological status and age as the variables with the most valuable information in the model. The poorest relevance in the analysis was for the duration of gaming problems and socioeconomic levels. Modularity analysis grouped the nodes within four clusters. Identification of the variables with the highest centrality/linkage can be particularly useful for developing precise management plans to prevent and treat gaming disorder related problems.

Neural substrates of deficient cognitive control in individuals with severe internet gaming disorder

BACKGROUND AND AIMS

Internet gaming disorder (IGD) is rapidly becoming a worldwide health concern. The prefrontal-subcortical model of self-regulation emphasizes that an impaired prefrontal cognitive control system and an overwhelming subcortical reward-seeking system are both crucial factors in health problems, including addiction. This study focused on the cognitive control system of IGD, aiming to investigate whether cognitive control is altered and the underlying neural correlates in college students with IGD.

METHODS

Thirty college students with IGD and twenty-five matched healthy controls were asked to complete a stop-signal task that measures cognitive control while being monitored by functional magnetic resonance imaging (fMRI).

RESULTS

Compared to the controls, only the college students with severe IGD, rather than those with mild IGD, had deficient brain activity involved in inhibitory control and response execution (specifically, the inferior frontal gyrus, anterior cingulate cortex and primary motor cortex); this result implies that cognitive control deficits are closely linked to addiction severity in individuals with IGD. Regarding performance monitoring function, college students with IGD exhibited unabated behavioral and brain activity, as did the control group.

CONCLUSIONS

Combined with our previous finding that the subcortical reward system was enhanced in individuals with IGD, the present findings extend the prefrontal-subcortical model of self-regulation from the perspective of IGD in a college student population and thus provide useful insight for the effective prevention and treatment of IGD.

Gaming to relieve tension or anxiety and associations with health functioning, substance use and physical violence in high school students

Gaming is popular among youth and gaming disorders have been introduced recently into psychiatric nomenclature systems. Motivations underlying gaming may include involvement to reduce negative emotional states and thus may link to psychiatric and overall health. Thus, the extent to which adolescents engage in gaming to relieve anxiety warrants additional investigation. Data from 2005 Connecticut high-school students were used to examine how adolescents who reported gaming to relieve tension or anxiety differed from those who reported gaming but not to relieve tension or anxiety on measures of demographics, academic performance, general health, extracurricular activities, dysphoria/depression symptoms, substance use, and aggressive or violent behaviors. Chi-square analyses and binomial and multinomial logistic regression models were conducted. Gaming to relieve anxiety was more prevalent in boys and Hispanic and Asian adolescents and associated with less extracurricular involvement, poorer academic performance, increased cigarette and other drug use, problematic internet use, and depression. Participants with gaming to relieve tension or anxiety were also more likely to report weapon-carrying, missing school because they felt unsafe, having been threatened with a weapon, having engaged in physical fights, and having experienced injuries from fights. As gaming to relieve anxiety was related to mental-health- and functioning-related measures, additional research is needed to examine the precise natures of these relationships and to translate the information into improved intervention strategies.

Disrupted prefrontal regulation of striatum-related craving in Internet gaming disorder revealed by dynamic causal modeling: results from a cue-reactivity task

BACKGROUND

Studies of Internet gaming disorder (IGD) suggest an imbalanced relationship between cognitive control and reward processing in people with IGD. However, it remains unclear how these two systems interact with each other, and whether they could serve as neurobiological markers for IGD.

METHODS

Fifty IGD subjects and matched individuals with recreational game use (RGU) were selected and compared when they were performing a cue-craving task. Regions of interests [anterior cingulate cortex (ACC), lentiform nucleus] were selected based on the comparison between brain responses to gaming-related cues and neutral cues. Directional connectivities among these brain regions were determined using Bayesian estimation. We additionally examined the posterior cingulate cortex (PCC) in a separate analysis based on data implicating the PCC in craving in addiction.

RESULTS

During fixed-connectivity analyses, IGD subjects showed blunted ACC-to-lentiform and lentiform-to-ACC connectivity relative to RGU subjects, especially in the left hemisphere. When facing gaming cues, IGD subjects trended toward lower left-hemispheric modulatory effects in ACC-to-lentiform connectivity than RGU subjects. Self-reported cue-related craving prior to scanning correlated inversely with left-hemispheric modulatory effects in ACC-to-lentiform connectivity.

CONCLUSIONS

The results suggesting that prefrontal-to-lentiform connectivity is impaired in IGD provides a possible neurobiological mechanism for difficulties in controlling gaming-cue-elicited cravings. Reduced connectivity ACC-lentiform connectivity may be a useful neurobiological marker for IGD.

The gray matter volume in superior frontal gyrus mediates the impact of reflection on emotion in Internet gaming addicts

Internet gaming disorder (IGD) is becoming a prevalent mental health concern around the world. However, the relationship among brain gray matter volume (GMV), emotion induced by decision-making and the level of reflection in IGD participants has not been fully elucidated to date. The current study aimed to explore this issue by combining a sequential decision task and voxel-based morphometry. Twenty-six IGD participants and 28 demographically matched healthy controls were recruited. After collecting Rumination-Reflection questionnaire data and high-resolution T1-weighted MRI data, participants were asked to complete a sequential decision task. The results demonstrated that compared to healthy controls, IGD participants exhibited significantly decreased GMV in the superior frontal gyrus (SFG). Moreover, GMV in the SFG of IGD participants fully mediated the impact of reflection level on the emotion of loss outcome during the sequential decision task. These results indicate that IGD is associated with reduced GMV in the SFG, and this structural change in IGD contributes to a particular relationship between the level of reflection and regret emotion for loss outcome in the sequential decision task.

Distinct patterns of prefrontal cortical disengagement during inhibitory control in addiction: A meta-analysis based on population characteristics

Prefrontal cortical dysfunctions underlying inhibitory control deficits in addiction are complex and likely dependent on population characteristics. Here, we conducted a meta-analysis to examine alterations in brain activations during response inhibition in addicted individuals. We characterized imaging findings based on substance use status, diagnosis, substance classes, and task performance. Results revealed in those with active drug addiction hypoactivation of the left dorsal anterior cingulate cortex (dACC) and right middle frontal gyrus (MFG), compared with healthy controls. Weakening of the dACC and MFG activations was particularly pronounced in nicotine users, respectively. Impaired task performance was also associated with diminished MFG activation. In contrast, abstinent users did not exhibit any significant differences compared with healthy controls. Those with behavioral addictions were characterized by higher midcingulate cortical activation. Thus, the neural disengagement during response inhibition in active drug addiction was limited to a small number of prefrontal cortical regions and dependent on population characteristics. Finally, the evidence for potential normalization of hypofrontality following substance use cessation highlights the benefits of abstinence in restoring cerebral functions.

Gender-related differences in frontal-parietal modular segregation and altered effective connectivity in internet gaming disorder

BACKGROUND

Although previous studies have revealed gender-related differences in executive function in internet gaming disorder (IGD), neural mechanisms underlying these processes remain unclear, especially in terms of brain networks.

METHODS

Resting-state fMRI data were collected from 78 subjects with IGD (39 males, 20.8 ± 2.16 years old) and 72 with recreational game use (RGU) (39 males, 21.5 ± 2.56 years old). By utilizing graph theory, we calculated participation coefficients among brain network modules for all participants and analyzed the diagnostic-group-by-gender interactions. We further explored possible causal relationships between networks through spectral dynamic causal modeling (spDCM) to assess differences in between-network connections.

RESULTS

Compared to males with RGU, males with IGD demonstrated reduced modular segregation of the frontal-parietal network (FPN). Male IGD subjects also showed increased connections between the FPN and cingulo-opercular network (CON); however, these differences were not found in female subjects. Further spDCM analysis indicated that the causal influence from CON to FPN in male IGD subjects was enhanced relative to that of RGU males, while this influence was relatively reduced in females with IGD.

CONCLUSIONS

These results suggest poor modular segmentation of the FPN and abnormal FPN/CON connections in males with IGD, suggesting a mechanism for male vulnerability to IGD. An increased "bottom-up" effect from the CON to FPN in male IGD subjects could reflect dysfunction between the brain networks. Different mechanisms may underlie in IGD, suggesting that different interventions may be optimal in males and females with IGD.

Enhanced neural responses in specific phases of reward processing in individuals with Internet gaming disorder

BACKGROUND AND AIMS

Internet gaming disorder (IGD) has become a global health problem. The self-regulation model noted that a shift to reward system, whether due to overwhelming reward-seeking or impaired control, can lead to self-regulation failures, e.g., addiction. The present study focused on the reward processing of IGD, aiming to provide insights into the etiology of IGD. Reward processing includes three phases: reward anticipation, outcome monitoring and choice evaluation. However, it is not clear which phases of reward processing are different between individuals with IGD and healthy controls (HC).

METHODS

To address this issue, the present study asked 27 individuals with IGD and 26 HC to complete a roulette task during a functional MRI scan.

RESULTS

Compared with HC, individuals with IGD preferred to take risks in pursuit of high rewards behaviorally and showed exaggerated brain activity in the striatum (nucleus accumbens and caudate) during the reward anticipation and outcome monitoring but not during the choice evaluation.

DISCUSSION

These results reveal that the oversensitivity of the reward system to potential and positive rewards in college students with IGD drives them to approach risky options more frequently although they are able to assess the risk values of options and the correctness of decisions properly as HC do.

CONCLUSIONS

These findings provide partial support for the application of the self-regulation model to the IGD population. Moreover, this study enriches this model from the perspective of three phases of reward processing and provides specific targets for future research regarding effective treatment of IGD.

A systematic review and meta-analysis on the clinical implications of probability discounting among individuals with Internet gaming disorder

The significance of probability discounting (PD) among individuals with Internet gaming disorder (IGD) remains unclear. Following the PRISMA guidelines, we systematically searched the PubMed, Embase, and ScienceDirect databases for English articles on Internet addiction that included comparison between individuals with and without IGD as well as probabilistic discounting task as the main outcome from January 1970 to July 2020 using the appropriate keyword strings. The primary outcome was the overall difference in rate of PD, while the secondary outcomes included the difference in PD with magnitude of probabilistic reward and response time of the PD task. Effect size (ES) was calculated through dividing the group means (e.g., h value or AUC) by the pooled standard deviations of the two groups. A total of five studies with 300 participants (i.e., IGD group, n = 150, mean age = 20.27 ± 2.68; healthy controls, n = 150, mean age = 20.70 ± 2.81) were analyzed. The IGD group was more willing to take risks in probabilistic gains but performances on probabilistic losses were similar between the two groups. The IGD group also exhibited a shorter response time (Hedge's g = - 0.51; 95%CI = - 0.87 to - 0.15). Meta-regression demonstrated a positive correlation between maximum reward magnitude and PD rate (p < 0.04). However, significant publication bias was noted among the included studies (Egger's test, p < 0.01). In conclusion, individuals with IGD seemed more impulsive in making risky decisions, especially when the potential gains were expected. Our findings not only supported the use of PD for assessing individuals with IGD but may also provide new insights into appropriate interventions.

Monetary Reward Discounting, Inhibitory Control, and Trait Impulsivity in Young Adults With Internet Gaming Disorder and Nicotine Dependence

Internet Gaming Disorder (IGD) has been considered a potential behavioral or non-substance addiction that requires further investigation. Recognition of the commonalities between IGD and Substance Use disorders (SUD) would be of great help to better understand the basic mechanisms of addictive behaviors and excessive Internet gaming. However, little research has targeted a straightforward contrast between IGD and SUD on neuropsychological aspects. The present study thus aimed to explore the associations of reward processing and inhibitory control with IGD and nicotine dependence (ND) in young adults. Fifty-eight IGD and 53 ND individuals, as well as 57 age- and gender-matched healthy controls, were assessed with a series of measurements including the Delay-discounting Test (DDT), Probability Discounting Test (PDT), the Stroop Color-Word Task, a revised Go/No Go Task, and the Barratt Impulsiveness Scale (BIS-11). Multivariate analysis of variance (mANOVA) models revealed that both IGD and ND groups scored higher than healthy controls on the BIS-11 attentional, motor, and non-planning impulsiveness (Cohen's d = 0.41-1.75). Higher degrees of delay discounting on the DDT were also found in IGD and ND groups compared to healthy controls (Cohen's d = 0.53-0.69). Although IGD group did not differ from healthy controls on the PDT, ND group had a lower degree of probability discounting than healthy controls (Cohen's d = 0.55), suggesting a reduction in risk aversion. Furthermore, ND subjects showed a lower correct accuracy in the incongruent trials of the Stroop task than healthy controls (Cohen's d = 0.61). On the Go/No Go task, both IGD and ND groups had a lower correct accuracy in the No-Go trials than healthy controls (Cohen's d = 1.35-1.50), indicating compromised response inhibition. These findings suggested that IGD was linked to both anomalous reward discounting and dysfunctional inhibitory control, which was comparable with one typical SUD category (i.e., ND). This study might promote a better understanding of the pathogenesis of IGD as a potential addictive disorder similar to SUD.

Impaired Learning From Errors and Punishments and Maladaptive Avoidance-General Mechanisms Underlying Self-Regulation Disorders?

Self-regulation (SR) is an important human function that relates to quality of life in multiple domains including mental health. Previous studies have found important correlates of low SR including impulsivity and poor emotional regulation; however, underpinnings of low SR are incompletely understood. Individuals low in SR frequently engage in maladaptive behaviors (substance abuse, procrastination, etc.) despite negative consequences. This phenomenon suggests that impaired learning from errors and punishments may be important mechanisms underlying low SR. Consistently, previous studies observed impaired error processing in a wide spectrum of individuals with low SR and impaired learning from errors and punishments in SR-related disorders. We also note a possible role for poor emotional regulation and refer to concepts suggesting that engaging in maladaptive behaviors may serve as short term emotion regulation strategies aimed at avoiding or alleviating negative affect. We speculate on transdiagnostic factors underlying poor SR. We propose that impaired error processing (possibly related to striatal functioning) may prevent subjects with low SR from learning from errors and punishments and thus learning better SR skills or tendencies. Additionally, impaired coping in emotionally challenging situations, possibly related to prefrontal-cortical functioning, may lead to maladaptive avoidance. Moreover, maladaptive behaviors may be reinforced by the temporary decreases in negative affect and rewarding values of behaviors. Given existing knowledge gaps, we call for more extensive research and describe possible directions and challenges for future studies.

Structural and Functional Brain Abnormalities in Internet Gaming Disorder and Attention-Deficit/Hyperactivity Disorder: A Comparative Meta-Analysis

Background: Patients with Internet gaming disorder (IGD) and attention-deficit/hyperactivity disorder (ADHD) have high comorbidity but it is still unknown whether these disorders have shared and distinctive neuroimage alterations. Objective: The aim of this meta-analysis was to identify shared and disorder-specific structural, functional, and multimodal abnormalities between IGD and ADHD. Methods: A systematic literature search was conducted for whole-brain voxel-based morphometry (VBM) and functional magnetic resonance imaging (fMRI) studies comparing people with IGD or ADHD with healthy controls. Regional gray matter volume (GMV) and fMRI differences were compared over the patient groups and then a quantitative comparison was performed to find abnormalities (relative to controls) between IGD and ADHD using seed-based d mapping meta-analytic methods. Result: The meta-analysis contained 14 IGD VBM studies (contrasts covering 333 IGDs and 335 HCs), 26 ADHD VBM studies (1,051 patients with ADHD and 887 controls), 30 IGD fMRI studies (603 patients with IGD and 564 controls), and 29 ADHD fMRI studies (878 patients with ADHD and 803 controls). Structurally, VBM analysis showed disorder-specific GMV abnormality in the putamen among IGD subjects and orbitofrontal cortex in ADHD and shared GMV in the prefrontal cortex. Functionally, fMRI analysis discovered that IGD-differentiating increased activation in the precuneus and shared abnormal activation in anterior cingulate cortex, insular, and striatum. Conclusion: IGD and ADHD have shared and special structural and functional alterations. IGD has disorder-differentiating structural alterations in the putamen and ADHD has alterations in the orbitofrontal cortex. Disorder-differentiating fMRI activations were predominantly observed in the precuneus among IGD subjects and shared impairing function connection was in the rewards circuit (including ACC, OFC, and striatum).

Desire thinking promotes decisions to game: The mediating role between gaming urges and everyday decision-making in recreational gamers

INTRODUCTION

Desire thinking is a voluntary cognitive process that involves the imaginal forecast of a desired activity and the verbal perseveration with plans and good reasons for engaging in it. Considering theoretical models arguing that specific decision-making processes may be involved in the development of gaming disorder, we hypothesized that an initial urge to game might be accelerated by desire thinking, leading to the decision to game in an everyday setting although the gaming behavior may conflict with another activity or certain other goals.

METHODS

A pre-study helped developing a catalogue of situations that provides forced-choice scenarios warranting a decision for or against gaming. To explore the postulated sequence of cognitive and affective events, a serial mediation model with urge to game as predictor, decision to game as dependent variable, and imaginal prefiguration and verbal perseveration as mediators was tested in a sample of 118 recreational gamers with varying degrees of gaming intensity.

RESULTS

The pre-study revealed a catalogue of 18 conflicting situations that likely happen in the daily life of gamers, containing conflicting activities such as job/educational performance and meeting friends/family/acquaintances. In the sequential mediation model, the desire thinking facets imaginal prefiguration and verbal perseveration fully mediated the relation between an initial urge and the decision to game.

CONCLUSIONS

The mediation model emphasizes the serial ordinance of desire thinking facets and their role in motivating decisions to game after an initial urge has been experienced. Results may indicate that desire thinking plays a considerable role in problematic gaming tendencies.

Attenuated self-serving bias in people with internet gaming disorder is related to altered neural activity in subcortical-cortical midline structures

BACKGROUND

To protect and maintain the positivity of self-concept, normal people usually show a self-serving bias (internal attribution of positive events and external attribution of negative events) by the motives of self-enhancement and self-protection. Additionally, self-serving assessments predominantly activate the subcortical-cortical midline structures (CMS) in healthy individuals. However, little is known about self-serving bias and its underlying neural correlates among individuals with Internet gaming disorder (IGD).

METHODS

Twenty-four participants with IGD and 25 recreational Internet gaming users (RGUs) were scanned while attributing the causes of positive/negative self- and other-related events that could occur in both the game-world and real-world contexts. Region-of-interest (within CMS regions) and parametric analysis were performed to investigate the neural correlates of self-serving bias in IGD.

RESULTS

Behaviorally, the IGD participants attributed more negative and fewer positive events to themselves than RGU participants in both contexts. Neurally, during the attributions of negative events, the IGD participants exhibited increased ventromedial prefrontal cortex (vmPFC) activation in both contexts compared with RGU participants. Higher vmPFC activation was associated with weaker self-protective motivation in the IGD group. Meanwhile, during the attributions of positive events, the IGD participants exhibited decreased precuneus/posterior cingulate cortex activation in the real world compared with RGU participants. Parametric analysis showed a reduced positive correlation between precuneus activation and self-attribution ratings of positive events in the real world in the IGD group relative to the RGU group.

CONCLUSION

These results suggest that individuals with IGD show an attenuated self-serving bias and altered brain activity within CMS regions involved in self-attribution, providing evidence for the negative self-concept and weakened abilities in both self-enhancement and self-protection in IGD.

Males are more sensitive to reward and less sensitive to loss than females among people with internet gaming disorder: fMRI evidence from a card-guessing task

BACKGROUND

Many studies have found an interesting issue in the Internet gaming disorder (IGD): males are always observed to be the majority. However, there are little research to exploring the differences in the neural mechanisms between males and females in decision-making process among people with IGD. Therefore, explore the reward/loss processing between different gender with IGD could help in understanding the underlying neural mechanism of IGD.

METHODS

Data from functional magnetic resonance imaging (fMRI) were collected from 111 subjects (IGD: 29 males, 25 females; recreational internet game user (RGU): 36 males, 21 females) while they were performing a card-guessing task. We collected and compared their brain features when facing the win and loss conditions in different groups.

RESULTS

For winning conditions, IGD group showed hypoactivity in the lingual gyrus than RGU group, male players showed hyperactivity in the left caudate nucleus, bilateral cingulate gyrus, right middle frontal gyrus (MFG), right precuneus and inferior parietal lobule relative to the females. And significant sex-by-group interactions results showed higher brain activities in the thalamus, parahippocampal gyrus and lower brain activities in Inferior frontal gyrus (IFG) were observed in males with IGD than females. For losing conditions, IGD group showed hypoactivity in the left lingual gyrus, parahippocampal gyrus and right anterior cingulate cortex (ACC) compared to the RGU group, male players showed hyperactive left caudate nucleus and hypoactive right middle occipital gyrus relative to females. And significant sex-by-group interactions results showed that compared to females with IGD, males with IGD showed decreased brain activities in the IFG and lingual gyrus.

CONCLUSIONS

First, there appeared to be no difference in reward processing between the IGD and RGU group, but IGD showed less sensitivity to loss. Secondly, male players showed more sensitivity to rewards and less sensitivity to losses. Last but not least, males and females showed opposite activation patterns in IGD degree and rewards/losses processing. And male IGD subjects are more sensitive to reward and less sensitive to loss than females, which might be the reason for the gender different rates on IGD.

Addiction severity modulates the precuneus involvement in internet gaming disorder: Functionality, morphology and effective connectivity

Although higher precuneus activation has often been observed in subjects with addictions when facing addiction-relevant cues, the recruitment of the precuneus is not consistent across studies. Here, we examined the extent to which addiction severity may relate to precuneus involvement during cue reactivity in internet gaming disorder (IGD). We recruited 65 subjects with IGD, collected brain responses when exposed to gaming cues and assessed brain structure. We correlated IGD severity with brain responses during a cue-craving task, precuneus volume, and connectivity with respect to inputs/outputs to/from the precuneus. In the cue-craving task, IGD severity was positively correlated with precuneus activation when exposed to gaming cues. IGD severity was also positively correlated with the volume of precuneus and connectivity from the hippocampal gyrus to the precuneus. IGD severity was also negatively correlated with connectivity from the middle frontal gyrus to the precuneus. In IGD, IGD severity relates to precuneus involvement with respect to functionality, morphology, and connectivity. The precuneus may act as a platform for integrating potential contradictory information between executive control and sub-cortical cravings.

A preliminary study of disrupted functional network in individuals with Internet gaming disorder: Evidence from the comparison with recreational game users

Although online gaming may lead to Internet gaming disorder (IGD), most players are recreational game users (RGU) who do not develop IGD. So far, the topological organization of whole-brain functional networks in IGD remains poorly understood. The inclusion of RGU as a control group could minimize the potential effects of gaming experience and gaming-related cue familiarity on the neural characteristics of IGD subjects. In the present study, we applied graph theoretical analysis to preliminarily explore the topological organization of intrinsic functional brain networks in IGD. 61 IGD participants and 61 matched RGU participants were recruited to undergo a resting-state functional magnetic resonance imaging scan. The whole-brain functional networks were constructed by thresholding partial correlation matrices of 90 brain regions, and graph-based approaches were applied to analysis their topological attributes, including small-world, efficiency, and nodal centralities. Both of IGD and RGU groups showed efficient and economic small-world topology in brain functional networks. Although there was no significant group difference in global properties, subjects with IGD as compared to those with RGU showed increased nodal centralities in the reward, craving, emotional memory and sensory-motor processing regions. These results suggest that the functional network dysfunction, characterizing by heightened incentive motivation and sensory-motor coordination, may provide a new perspective for understanding the neural characteristics underlying IGD.

Differences in associations between problematic video-gaming, video-gaming duration, and weapon-related and physically violent behaviors in adolescents

Seemingly mixed findings have been reported on possible relationships between video-gaming and violent or aggressive behaviors. Given the prevalence of gaming in adolescents and potential harms associated with violent behaviors, relationships between problematic gaming, gaming engagement, and risk behaviors involving weapons and physical violence require further research. This study examined in a large sample of high-school students the relationships between problem-gaming severity, gaming duration, and violence-related measures including weapon-carrying, having been threatened by someone with a weapon, perceived insecurity, physical fights and serious fights leading to injuries. Potential moderation by sensation-seeking and impulsivity was also tested. Participants were 3,896 Connecticut high-school adolescents. Chi-square, logistic regression, and moderation models were conducted. Adolescents with at-risk/problem gaming, compared to low-risk and non-gaming adolescents, reported more weapon-carrying, having been threatened with weapons, feeling unsafe at school, and serious fighting leading to injury. Among those reporting gaming, weekly time spent gaming was associated with problem-gaming severity. Those with longer (versus shorter) gaming durations were more likely to report weapon-carrying and feeling unsafe at school. Sensation-seeking moderated associations between at-risk/problem gaming and weapon-carrying frequency. Associations between gaming quantity and problem-gaming severity and measures of weapon-carrying and physical violence in adolescents suggest that understanding further their mechanistic relationships may be important in promoting safer developmental trajectories for youth. Future longitudinal studies may provide important insight into the etiologies underlying these relationships and such information may help develop more effective prevention and intervention strategies.

Video Game Addiction and Emotional States: Possible Confusion Between Pleasure and Happiness?

Internet gaming disorder is characterized by a severely reduced control over gaming, resulting in an increasing gaming time and leading to negative consequences in many aspects of the individual life: personal, family, social, occupational and other relevant areas of functioning (World Health Organization). In the last years, the significant boom in using video games has been raising health issues that remain insufficiently understood. The extent of this phenomenon (the estimated prevalence is between 1.7 and 10% of the general population) has led the mentioned Organization to include gaming disorders in the list of mental health conditions (2018). Several studies show converging findings that highlight the common brain activities between substance use disorders and behavioral addictions (i.e., gaming disorders). Addiction specialists observed that addict subjects tend to confuse pleasure with happiness when linking emotional states to their addictive activities. As far as we know, beyond the mentioned observations, distinguishing the perception of these two emotional states in the frame of an addiction has not been yet the object of formal research. This study aims at examining the possible confusion between pleasure and happiness within the addiction sphere. Video game addiction has been chosen to explore the possible occurrence of this perceptional distortion. A mixed design lab-based study was carried out to compare between video games addicts and non-addicts (between-subjects), and video games-related activities and neutral activities (within-subject). Emotional reactions were gauged by self-reported scales and physiological data acquired through a range of biosensors: Relaxation and Hearth Rate. From a therapeutic standpoint, this research intends to explore alternatives to deal with this sort of disorders. More specifically, at the cognitive level, the idea is elaborating guidelines to develop patients' insights into these emotional states and thus increasing their ability to handle them. Overall, several indices resulting from this study constitute a bundle of arguments that argue in favor of the confusion between pleasure and happiness made by addict users when associating their affective states to video gaming. Furthermore, this approach illustrates how reappraising emotions may contribute to reducing the perceptional distortion of these emotional states.

Impulsivity and Response Inhibition Related Brain Networks in Adolescents With Internet Gaming Disorder: A Preliminary Study Utilizing Resting-State fMRI

Background and Aims: Internet gaming disorder (IGD), as a relapse disease, has become a common mental health problem among Asian teenagers. Functional connections in the prefrontal lobo-striatum affect changes in impulsivity and inhibition. Therefore, exploration of the directional connections of the relevant brain regions in the prefrontal-striatal circuit and the synchronization level of the two hemispheres will help us to further understand the neural mechanism of IGD, which can provide guidance for the development of prevention and intervention strategies. Methods: Twenty-two adolescents with IGD, recruited through various channels, composed the IGD group. Twenty-six subjects, matching age, gender, and education level, were included in a recreational internet game users (RGUs) control group. Impulsivity and response inhibition were tested via general questionnaire, the Internet Addiction Test (IAT), the Barratt impulsivity scale-11 (BIS-11), and a Stroop color-word task. A Granger causality analysis (GCA) was used to calculate the directional connection between the prefrontal and striatum with the dorsolateral prefrontal cortex (DLPFC) as a region of interest (ROI). We chose voxel-mirrored homotopic connectivity (VMHC) to determine brain hemisphere functional connectivity in the prefrontal-striatal circuits. Results: We found significant differences in impulsivity between the IGD group and RGU group, with members of the IGD group exhibiting higher impulsivity. Additionally, the response inhibition of adolescents with IGD in the Stroop color-word task was impaired. There was a significant difference in the directed connection of the left DLPFC and dorsal striatum between the IGD group and the RGU group. Conclusions: This study confirmed the role of prefrontal-striatal circuits in the neural mechanism of IGD in adolescents. In the IGD group, bilateral cerebral medial orbitofrontal cortex (mOFC) synchronization was significantly reduced, which indicated that mOFC signal transmission in both hemispheres of the brain might be affected by impulse behavior and impaired response inhibition.

Cue-elicited craving-related lentiform activation during gaming deprivation is associated with the emergence of Internet gaming disorder

Internet gaming disorder (IGD) is associated with negative health measures. However, little is known regarding the brain mechanisms or cognitive factors that may predict transitions from regular game use (RGU) to IGD. Such knowledge may help identify individuals who are particularly vulnerable to IGD and aid in prevention efforts. One hundred forty-nine individuals with RGU were scanned when they were performing a cue-elicited-craving task before gaming and after gaming was suddenly ceased. One year later, 23 were found to have developed IGD (RGU_IGD). We compared the original data from these 23 RGU_IGD subjects and 23 one-to-one matched subjects still meeting criteria for RGU (RGU_RGU). RGU_IGD and RGU_RGU subjects showed similarities in the cue-elicited-craving task before gaming. Significant group-by-time interaction identified the bilateral lentiform nucleus. Post hoc analysis showed the interaction was related to increased activation in the RGU_IGD subjects following gaming. Significant correlations were observed between self-reported cravings and lentiform activation in the RGU_IGD subjects. Among individuals with RGU, gaming-cue-induced lentiform activation following a session of gaming may predict subsequent development of IGD. The findings suggest a biological mechanism for emergence of IGD that may help inform prevention interventions.

Cognitive deficits in problematic internet use: meta-analysis of 40 studies

BACKGROUND

Excessive use of the internet is increasingly recognised as a global public health concern. Individual studies have reported cognitive impairment in problematic internet use (PIU), but have suffered from various methodological limitations. Confirmation of cognitive deficits in PIU would support the neurobiological plausibility of this disorder.

AIMS

To conduct a rigorous meta-analysis of cognitive performance in PIU from case-control studies; and to assess the impact of study quality, the main type of online behaviour (for example gaming) and other parameters on the findings.

METHOD

A systematic literature review was conducted of peer-reviewed case-controlled studies comparing cognition in people with PIU (broadly defined) with that of healthy controls. Findings were extracted and subjected to a meta-analysis where at least four publications existed for a given cognitive domain of interest.

RESULTS

The meta-analysis comprised 2922 participants across 40 studies. Compared with controls, PIU was associated with significant impairment in inhibitory control (Stroop task Hedge's g = 0.53 (s.e. = 0.19-0.87), stop-signal task g = 0.42 (s.e. = 0.17-0.66), go/no-go task g = 0.51 (s.e. = 0.26-0.75)), decision-making (g = 0.49 (s.e. = 0.28-0.70)) and working memory (g = 0.40 (s.e. = 0.20-0.82)). Whether or not gaming was the predominant type of online behaviour did not significantly moderate the observed cognitive effects; nor did age, gender, geographical area of reporting or the presence of comorbidities.

CONCLUSIONS

PIU is associated with decrements across a range of neuropsychological domains, irrespective of geographical location, supporting its cross-cultural and biological validity. These findings also suggest a common neurobiological vulnerability across PIU behaviours, including gaming, rather than a dissimilar neurocognitive profile for internet gaming disorder.

DECLARATION OF INTEREST

S.R.C. consults for Cambridge Cognition and Shire. K.I.'s research activities were supported by Health Education East of England Higher Training Special interest sessions. A.E.G.'s research has been funded by Innovational grant (VIDI-scheme) from ZonMW: (91713354). N.A.F. has received research support from Lundbeck, Glaxo-SmithKline, European College of Neuropsychopharmacology (ECNP), Servier, Cephalon, Astra Zeneca, Medical Research Council (UK), National Institute for Health Research, Wellcome Foundation, University of Hertfordshire, EU (FP7) and Shire. N.A.F. has received honoraria for lectures at scientific meetings from Abbott, Otsuka, Lundbeck, Servier, Astra Zeneca, Jazz pharmaceuticals, Bristol Myers Squibb, UK College of Mental Health Pharmacists and British Association for Psychopharmacology (BAP). N.A.F. has received financial support to attend scientific meetings from RANZCP, Shire, Janssen, Lundbeck, Servier, Novartis, Bristol Myers Squibb, Cephalon, International College of Obsessive-Compulsive Spectrum Disorders, International Society for Behavioral Addiction, CINP, IFMAD, ECNP, BAP, the World Health Organization and the Royal College of Psychiatrists. N.A.F. has received financial royalties for publications from Oxford University Press and payment for editorial duties from Taylor and Francis. J.E.G. reports grants from the National Center for Responsible Gaming, Forest Pharmaceuticals, Takeda, Brainsway, and Roche and others from Oxford Press, Norton, McGraw-Hill and American Psychiatric Publishing outside of the submitted work.

Altered brain functional networks in Internet gaming disorder: independent component and graph theoretical analysis under a probability discounting task

OBJECTIVES

Internet gaming disorder (IGD) is becoming a matter of concern around the world. However, the neural mechanism underlying IGD remains unclear. The purpose of this paper is to explore the differences between the neuronal network of IGD participants and that of recreational Internet game users (RGU).

METHODS

Imaging and behavioral data were collected from 18 IGD participants and 20 RGU under a probability discounting task. The independent component analysis (ICA) and graph theoretical analysis (GTA) were used to analyze the data.

RESULTS

Behavioral results showed the IGD participants, compared to RGU, prefer risky options to the fixed ones and spent less time in making risky decisions. In imaging results, the ICA analysis revealed that the IGD participants showed stronger functional connectivity (FC) in reward circuits and executive control network, as well as lower FC in anterior salience network (ASN) than RGU; for the GTA results, the IGD participants showed impaired FC in reward circuits and ASN when compared with RGU.

CONCLUSIONS

These results suggest that IGD participants were more sensitive to rewards, and they were more impulsive in decision-making as they could not control their impulsivity effectively. This might explain why IGD participants cannot stop their gaming behaviors even when facing severe negative consequences.

Meta-analyses of the functional neural alterations in subjects with Internet gaming disorder: Similarities and differences across different paradigms

Internet gaming disorder (IGD) has become a global public health concern due to its increasing prevalence and potential negative consequences. Researchers have sought to identify which brain regions are associated with this disorder. However, inconsistent results have been reported among studies due to the heterogeneity of paradigms and subjects. The present research aimed to combine the results of individual studies to provide a more coherent and powerful explanation. By selecting 40 studies utilizing a qualified whole-brain analysis, we performed a comprehensive series of meta-analyses that employed seed-based d mapping. We divided the existing experimental paradigms into 3 categories: game-related cue-reactivity, executive control, and risk-reward-related decision-making tasks. We divided all studies into three subgroups according to their paradigms. In cue-reactivity tasks, patients with IGD exhibited significant hyperactivation in the bilateral precuneus and bilateral cingulate and significant hypoactivation in the insula, but there were no differences in the striatum. In executive control tasks, patients with IGD displayed significant hyperactivation in the right superior temporal gyrus, bilateral precuneus, bilateral cingulate, and insula and hypoactivation in the left inferior frontal gyrus. In risky decision-making paradigms, IGD patients exhibited significant hyperactivation in the left striatum, right inferior frontal gyrus, and insula and hypoactivation in the left superior frontal gyrus, left inferior frontal gyrus, and right precentral gyrus. Our study aimed to discover the similarities among all studies and to explore the uniqueness of the different paradigms. This study further confirmed the critical role of reward circuitry and executive control circuitry in IGD but not under all conditions.

Research progress and debates on gaming disorder

Gaming disorder has become a significant issue in mental healthcare. While gaming is an important form of entertainment, excessive gaming may cause serious consequences for players. At present, there are still controversies in the academic community concerning the public health problems related to gaming disorder. This article attempts to expound the definition, epidemiology, aetiology, diagnosis, treatment and prevention of gaming disorder, in order to contribute to future conceptualization of gaming disorder.

Diagnostic and Classification Considerations Regarding Gaming Disorder: Neurocognitive and Neurobiological Features

Video gaming and Internet use have become a part of the everyday lives of many individuals, especially during adolescence. Given the health concerns related to problematic gaming behaviors, gaming disorder (GD) has been included in the version of the 11th edition of The International Classification of Diseases (ICD-11) ratified by the secretariat of the World Health Organization. Given these considerations and others (including debate regarding the most appropriate classification of GD and how best to prevent and treat the condition), there is a need for further research into GD. Specifically, we suggest that researching intermediate phenotypes focusing on cognitive and neurobiological function may help clarify GD's relationships to other addictive disorders and more accurately define their relationships with core and associated features of GD. Overlaps in neural activity, cognitive functioning, and other features suggest that GD shares similarities with gambling and substance-use disorders and may best be classified as an addictive disorder. Individuals with GD differ from those with regular game use (RGU) on neurocognitive levels. However, concerns have been raised with respect to the differences between GD and substance-use disorders in certain dimensional features, such as tolerance. Additionally, it has been argued that differences between GD and RGU may not be fully captured by nomenclature systems like the ICD-11. Nonetheless, individuals seek treatment for help with GD, despite the limited data available for effective treatments. As more data are gathered from investigations of GD, they should be translated into refining criteria for GD and optimizing interventions.