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

Prevalence of internet gaming disorder among Chinese adolescents: A systematic review and meta-analysis

This study aimed to evaluate the prevalence of IGD among Chinese adolescents. Articles published up to April 11, 2024 were retrieved from PubMed, Wiley Online Library, Embase, Web of Science, Ebsco, CNKI, and WanFang. Random-effects models and univariate meta-regression analyses were used to calculate prevalence and heterogeneity estimates with the support of Stata17.0 software. The prevalence of IGD in Chinese adolescents was 10 % (95 %CI: 8 %-12 %). Univariate regression analyses revealed some significant moderators of IGD prevalence, including gender, sample size, and survey year. Spatiotemporal analysis showed the prevalence of IGD varied considerably across provinces in different survey years.

Biomarkers of Internet Gaming Disorder-A Narrative Review

Since game mechanics and their visual aspects have become more and more addictive, there is concern about the growing prevalence of Internet gaming disorder (IGD). In the current narrative review, we searched PubMed and Google Scholar databases for the keywords "igd biomarker gaming" and terms related to biomarker modalities. The biomarkers we found are grouped into several categories based on a measurement method and are discussed in the light of theoretical addiction models (tripartite neurocognitive model, I-PACE). Both theories point to gaming-related problems with salience and inhibition. The first dysfunction makes an individual more susceptible to game stimuli (raised reward seeking), and the second negatively impacts resistance to these stimuli (decreased cognitive control). The IGD patients' hypersensitivity to reward manifests mostly in ventral striatum (VS) measurements. However, there is also empirical support for a ventral-to-dorsal striatal shift and transition from goal-directed to habitual behaviors. The deficits in executive control are demonstrated in parameters related to the prefrontal cortex (PFC), especially the dorsolateral prefrontal cortex (DLPFC). In general, the connection of PFC with reward under cortex nuclei seems to be dysregulated. Other biomarkers include reduced P3 amplitudes, high-frequency heart rate variability (HRV), and the number of eye blinks and saccadic eye movements during the non-resting state. A few studies propose a diagnostic (multimodal) model of IGD. The current review also comments on inconsistencies in findings in the nucleus accumbens (NAcc), anterior cingulate cortex (ACC), and precuneus and makes suggestions for future IGD studies.

Sex differences of neural connectivity in internet gaming disorder and its association with sleep quality: an exploratory fMRI study

Objectives

Sex-specific differences in internet gaming disorder (IGD) neurophysiology remain underexplored. Here we investigated sex-related variability in regional homogeneity (ReHo) and functional connectivity (FC) in IGD and their correlations with sleep quality.

Methods

Resting-state functional magnetic resonance imaging (fMRI) scans were performed on 52 subjects with IGD and 50 healthy controls (HCs). Two-way ANOVA was used to examine sex and diagnosis interactions in ReHo and FC, followed by post-hoc analyses to explore FC biomarkers for different sexes.

Results

In ReHo analysis, the four groups showed significant sex and diagnosis interactions in the right middle frontal gyrus (rMFG). FC analysis with rMFG as the seed region revealed a significant sex and diagnosis interaction effect in FC of the rMFG with the bilateral postcentral gyrus (PoCG). In male IGD group, FC between the rMFG and the bilateral PoCG correlates strongly with daytime dysfunction score and the Pittsburgh sleep quality inventory (PSQI) total score.

Conclusion

These findings emphasize the importance of considering sexual dimorphism in the neurobiology of IGD, which might influence subsequent treatment strategies.

Neural Network Dynamics and Brain Oscillations Underlying Aberrant Inhibitory Control in Internet Addiction

Previous studies have reported a role of alterations in the brain's inhibitory control mechanism in addiction. Mounting evidence from neuroimaging studies indicates that its key components can be evaluated with brain oscillations and connectivity during inhibitory control. In this study, we developed an internet-related stop-signal task with electroencephalography (EEG) signal recorded to investigate inhibitory control. Healthy controls and participants with Internet addiction were recruited to participate in the internet-related stop-signal task with 19-channel EEG signal recording, and the corresponding event-related potentials and spectral perturbations were analyzed. Brain effective connections were also evaluated using direct directed transfer function. The results showed that, relative to the healthy controls, participants with Internet addiction had increased Stop-P3 during inhibitory control, suggesting that they have an altered neural mechanism in impulsive control. Furthermore, participants with Internet addiction showed increased low-frequency synchronization and decreased alpha and beta desynchronization in the middle and right frontal regions compared to healthy controls. Aberrant brain effective connectivity was also observed, with increased occipital-parietal and intra-occipital connections, as well as decreased frontal-paracentral connection in participants with Internet addiction. These results suggest that physiological signals are essential in future implementations of cognitive assessment of Internet addiction to further investigate the underlying mechanisms and effective biomarkers.

Different cortical connectivities in human females and males relate to differences in strength and body composition, reward and emotional systems, and memory

Sex differences in human brain structure and function are important, partly because they are likely to be relevant to the male-female differences in behavior and in mental health. To analyse sex differences in cortical function, functional connectivity was measured in 36,531 participants (53% female) in the UK Biobank (mean age 69) using the Human Connectome Project multimodal parcellation atlas with 360 well-specified cortical regions. Most of the functional connectivities were lower in females (Bonferroni corrected), with the mean Cohen's d =  - 0.18. Removing these as covariates reduced the difference of functional connectivities for females-males from d =  - 0.18 to - 0.06. The lower functional connectivities in females were especially of somatosensory/premotor regions including the insula, opercular cortex, paracentral lobule and mid-cingulate cortex, and were correlated with lower maximum workload (r = 0.17), and with higher whole body fat mass (r =  - 0.17). But some functional connectivities were higher in females, involving especially the ventromedial prefrontal cortex and posterior cingulate cortex, and these were correlated with higher liking for some rewards such as sweet foods, higher happiness/subjective well-being, and with better memory-related functions. The main findings were replicated in 1000 individuals (532 females, mean age 29) from the Human Connectome Project. This investigation shows the cortical systems with different functional connectivity between females and males, and also provides for the first time a foundation for understanding the implications for behavior of these differences between females and males.

Neuroimaging correlates of internet gaming disorder: Can we achieve the promise of translating understandings of brain functioning into clinical advances?

Objectives

Here we aimed to consider the neural factors associated with internet gaming disorder (IGD), as well as the associations between these factors and existing treatments for the disorder.

Methods

A narrative review was conducted.

Results

Pharmacological as well as psychological treatments for IGD may be associated with specific changes in multiple brain areas and circuits. In particular, fronto-striatal and subcortical regions and pathways appear relevant to IGD and its treatment.

Conclusions

Neuroimaging holds promise for identifying specific mechanisms underlying IGD interventions. However, to date, firm conclusions are difficult to draw and more research examining neural mechanisms of empirically supported treatments for IGD is needed.

A systematic review and meta-analysis of risky decision-making in specific domains of problematic use of the internet: Evidence across different decision-making tasks

This systematic review summarizes empirical evidence on risky decision-making (objective risk and ambiguity) in specific domains of problematic use of the internet (PUI) focusing on online addictive behaviors. We conducted a pre-registered (PROSPERO: CRD42020188452) PubMed search for PUI domains: gaming, social-network use, online buying-shopping, online pornography use, and unspecified PUI. We used the Newcastle-Ottawa Scale for quality assessment. Relevant studies were identified only for gaming (n = 19), social-network use (n = 8), unspecified PUI (n = 7), and online gambling (n = 1). The meta-analyses included 25 studies (2498 participants) comparing PUI and control groups regarding decision-making performance under objective risk and ambiguity. Across PUI domains, individuals with PUI compared to control participants showed more disadvantageous decision-making in measures of objective risk (g = -0.42 [-0.69, -0.16], p = .002) but not ambiguity (g = -0.22 [-0.47, -0.04], p = .096). PUI domain and gender were significant moderators. In the risk domain, effects were particularly present in gaming disorder, especially in exclusively male samples. Overall, the paucity of empirical studies in the considered area necessitates further research to identify probable gender- and disorder-specific cognitive relationships.

Relationships Between Gaming Disorder, Risk Factors, and Protective Factors Among a Sample of Chinese University Students Utilizing a Network Perspective

Research has demonstrated that some risk and protective factors of gaming disorder (GD) have been identified. However, the interaction of GD with risk and protective factors has rarely been examined from a network analysis perspective. Therefore, the present study examined the relationships between GD, risk factors (i.e., social anxiety and fear of missing out), and protective factors (i.e., resilience, authenticity, and family closeness) utilizing a network analysis approach among a sample of Chinese university students. A cross-sectional study with 1364 participants was performed using the Gaming Disorder Test, the short version of Social Interaction Anxiety Scale (SIAS), the Chinese Trait-State Fear of Missing Out Scale (T-SFoMOSC), the Brief Resilience Scale (BRS), the Authenticity Scale, and a single item assessing family closeness. Social anxiety, FoMO, and two factors of authenticity (i.e., self-alienation and accepting external influence) had positive relationship with GD, while resilience, authentic living, and family closeness had negative relationship with GD. Social anxiety was identified as the core node in the domain-level network. The item "continuation or escalation of gaming" (gd3) and the item "gaming problems" (gd4) constituted the highest edge weight in the facet-level network. The network comparison demonstrated there were no significant differences in relation to network structures and global strengths between gender. The findings suggest bivariate relationships among GD, risk factors (i.e., social anxiety and fear of missing out), and protective factors (i.e., resilience, authenticity, and family closeness). Interventions for GD must be considered through preventing risk factors and increasing protective factors including improving the gaming motivation and maladaptive cognition to decrease negative emotion (e.g., social anxiety and FoMO), enhancing resilience, authentic living and parent-child relationship, as well as decreasing self-alienation and accepting external influence.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11469-023-01049-3.

Subgroups of internet gaming disorder based on addiction-related resting-state functional connectivity

AIMS

To identify subgroups of people with internet gaming disorder (IGD) based on addiction-related resting-state functional connectivity and how these subgroups show different clinical correlates and responses to treatment.

DESIGN

Secondary analysis of two functional magnetic resonance imaging (fMRI) data sets.

SETTING

Zhejiang province and Beijing, China.

PARTICIPANTS

One hundred and sixty-nine IGD and 147 control subjects.

MEASUREMENTS

k-Means algorithmic and support-vector machine-learning approaches were used to identify subgroups of IGD subjects. These groups were examined with respect to assessments of craving, behavioral activation and inhibition, emotional regulation, cue-reactivity and guessing-related measures.

FINDINGS

Two groups of subjects with IGD were identified and defined by distinct patterns of connectivity in brain networks previously implicated in addictions: subgroup 1 ('craving-related subgroup') and subgroup 2 ('mixed psychological subgroup'). Clustering IGD on this basis enabled the development of diagnostic classifiers with high sensitivity and specificity for IGD subgroups in 10-fold validation (n = 218) and out-of-sample replication (n = 98) data sets. Subgroup 1 is characterized by high craving scores, cue-reactivity during fMRI and responsiveness to a craving behavioral intervention therapy. Subgroup 2 is characterized by high craving, behavioral inhibition and activations scores, non-adaptive emotion-regulation strategies and guessing-task fMRI measures. Subgroups 1 and 2 showed largely opposite functional-connectivity patterns in overlapping networks.

CONCLUSIONS

There appear to be two subgroups of people with internet gaming disorder, each associated with differing patterns of brain functional connectivity and distinct clinical symptom profiles and gender compositions.

Associations between levels of Internet Gaming Disorder symptoms and striatal morphology-replication and associations with social anxiety

Background

Brain structural alterations of the striatum have been frequently observed in internet gaming disorder (IGD); however, the replicability of the results and the associations with social-affective dysregulations such as social anxiety remain to be determined.

Methods

The present study combined a dimensional neuroimaging approach with both voxel-wise and data-driven multivariate approaches to (i) replicate our previous results on a negative association between IGD symptom load (assessed by the Internet Gaming Disorder Scale-Short Form) and striatal volume, (ii) extend these findings to female individuals, and (iii) employ multivariate and mediation models to determine common brain structural representations of IGD and social anxiety (assessed by the Liebowitz Social Anxiety Scale).

Results

In line with the original study, the voxel-wise analyses revealed a negative association between IGD and volumes of the bilateral caudate. Going beyond the earlier study investigating only male participants, the present study demonstrates that the association in the right caudate was comparable in both the male and the female subsamples. Further examination using the multivariate approach revealed regionally different associations between IGD and social anxiety with striatal density representations in the dorsal striatum (caudate) and ventral striatum (nucleus accumbens). Higher levels of IGD were associated with higher social anxiety and the association was critically mediated by the multivariate neurostructural density variations of the striatum.

Conclusions

Altered striatal volumes may represent a replicable and generalizable marker of IGD symptoms. However, exploratory multivariate analyses revealed more complex and regional specific associations between striatal density and IGD as well as social anxiety symptoms. Variations in both tendencies may share common structural brain representations, which mediate the association between increased IGD and social anxiety.

Neural activations to loss anticipation mediates the association between difficulties in emotion regulation and screen media activities among early adolescent youth: A moderating role for depression

BACKGROUND

Screen media activities (SMAs; e.g., watching videos, playing videogames) have become increasingly prevalent among youth as ways to alleviate or escape from negative emotional states. However, neural mechanisms underlying these processes in youth are incompletely understood.

METHOD

Seventy-nine youth aged 11-15 years completed a monetary incentive delay task during fMRI scanning. Neural correlates of reward/loss processing and their associations with SMAs were explored. Next, brain activations during reward/loss processing in regions implicated in the processing of emotions were examined as potential mediating factors between difficulties in emotion regulation (DER) and engagement in SMAs. Finally, a moderated mediation model tested the effects of depressive symptoms in such relationships.

RESULT

The emotional components associated with SMAs in reward/loss processing included activations in the left anterior insula (AI) and right dorsolateral prefrontal cortex (DLPFC) during anticipation of working to avoid losses. Activations in both the AI and DLPFC mediated the relationship between DER and SMAs. Moreover, depressive symptoms moderated the relationship between AI activation in response to loss anticipation and SMAs.

CONCLUSION

The current findings suggest that DER link to SMAs through loss-related brain activations implicated in the processing of emotions and motivational avoidance, particularly in youth with greater levels of depressive symptoms. The findings suggest the importance of enhancing emotion-regulation tendencies/abilities in youth and, in particular, their regulatory responses to negative emotional situations in order to guide moderate engagement in SMAs.

The prevalence and possible risk factors of internet gaming disorder among adolescents and young adults: Systematic reviews and meta-analyses

BACKGROUND

As a spreading addictive behaviour in recent years, internet gaming disorder (IGD) has been studied a lot and the overall research results indicate that IGD has a high prevalence among adolescents and young adults (AYAs). To update the status quo of prevalence, it is necessary to conduct comprehensive analyses.

METHODS

On the premise of following the PRISMA statement, the study conducted two systematic reviews and meta-analyses to assess the global prevalence of IGD among AYAs and identify its possible risk factors. To achieve the goals, PubMed and CNKI databases were used to select the concerned studies published up to May 31, 2021. Heterogeneity was assessed using a funnel plot, Begg's test, Egger's test, and trim-and-fil method, followed by sensitivity analysis, subgroup analysis, and meta-regression analysis.

RESULTS

For the meta-analysis of prevalence, 407,620 participants from 155 reports in 33 countries were included. The pooled prevalence of IGD among AYAs was 9.9% (95% CI: 8.6%-11.3%, P = 0.000, I² = 94.4%), including 8.8% (95% CI: 7.5%-10.0%) among adolescents and 10.4% (95% CI: 8.8%-11.9%) among young adults. The following 12 factors are the possible risk factors of IGD among AYAs, which are stress, long average game time, family dysfunction, poor academic performance, being bullied, bullying, interpersonal problems, hyperactivity/inattention, anxiety, depression, emotional distress and low self-esteem.

CONCLUSIONS

This study confirms the prevalence and possible risk factors for IGD among AYAs. It's valuable in understanding the threat of IGD and finding intervention strategies for IGD among AYAs.

Prevalence of gaming disorder in East Asia: A comprehensive meta-analysis

Background and aims

Asian countries are deemed to be high prevalence areas for gaming disorder (GD). This meta-analysis is the first to synthesize the overall prevalence of GD in East Asia and investigate characteristics that influence prevalence estimates.

Methods

Systematic and independent searches were conducted across PubMed, Web of Science, Embase, PsycINFO, and the Cochrane Library since their inception to January 27, 2021. The Agency for Healthcare Research and Quality scale was used for quality assessment. A random effect model was used to calculate the overall GD prevalence and 95% confidence intervals (CIs).

Results

In total, 22 articles (26 studies) comprising 51,525 participants were included in this meta-analysis. The overall pooled prevalence of GD in East Asia was 12%, 95% CI (10%-15%); this figure was adjusted to 6%, 95% CI (3%-9%) for a representative sample. Higher prevalence was observed in males than in females (16% vs. 8%, respectively, P < 0.05). Subgroup and meta-regression analyses revealed that studies among gamers or those without random sampling reported significantly higher prevalence rates. There were no significant differences between countries/regions, sample size, quality score, proportion of males, and scale used.

Discussion and conclusions

The prevalence of GD in East Asia is higher than that in other world regions. Future studies should extend such epidemiological research to other regions to calculate the accurate prevalence of GD to benefit the local identification, prevention, policy formulation, and treatment efforts. Considering its negative effects, effective preventive and treatment measures for GD in East Asia need greater attention.

Considering gender differences in the study and treatment of internet gaming disorder

BACKGROUND AND AIMS

Internet gaming disorder (IGD) is a multifaceted and complex addictive disorder characterized by poor impulse control and altered reward sensitivities, among other features. IGD is a male-predominant condition, and gender-related differences may contribute importantly to the development and maintenance of, and recovery from, IGD.

METHODS

The current manuscript proposes a framework that incorporates gender-related considerations at different stages of IGD and proposes potential strategies for the prevention and treatment of IGD.

RESULTS

At the development stage, high impulsivity, impaired inhibitory control, and aggressive behaviors have been more frequently observed among males than females, suggesting potential risk factors for the development of IGD. Loneliness and other emotional dysregulation have been more frequently noted among females (than among males) with IGD. At the maintenance stage, males may be more sensitive to gaming-related rewards than females, and acute gaming behaviors may elicit higher cravings among males than among females and thus weaken their inhibitory control. In recovery, females with IGD have reported more negative mood states than males, and females' gaming behaviors have been linked with affective disorders.

DISCUSSIONS

The model proposed here highlights gender-related differences in modulating the behavioral and neural systems that contribute to a three-stage framework of IGD. Additional investigation into gender-related differences in IGD may further advance the field by uncovering complex relationships that may underlie vulnerability and provide insights into the development of gender-specific prevention and treatment strategies.

Gender-related differences in involvement of addiction brain networks in internet gaming disorder: Relationships with craving and emotional regulation

BACKGROUND

Abnormal interactions among addiction brain networks associated with intoxication, negative affect, and anticipation may have relevance for internet gaming disorder (IGD). Despite prior studies having identified gender-related differences in the neural correlates of IGD, gender-related differences in the involvement of brain networks remain unclear.

METHODS

One-hundred-and-nine individuals with IGD (54 males) and 111 with recreational game use (RGU; 58 males) provided resting-state fMRI data. We examined gender-related differences in involvement of addiction brain networks in IGD versus RGU subjects. We further compared the strength between and within addiction brain networks and explored possible relationships between the strength of functional connectivities within and between addiction brain networks and several relevant behavioral measures.

RESULTS

The addiction brain networks showed high correct classification rates in distinguishing IGD and RGU subjects in men and women. Male subjects with versus without IGD showed stronger functional connectivities between and within addiction brain networks. Moreover, the strength of the connectivity within the anticipation network in male IGD subjects was positively related to subjective craving. However, female subjects with versus without IGD showed decreased functional connections between and within addiction brain networks. The strength of connectivity between the anticipation and negative-affect brain networks in female IGD subjects was negatively related to maladaptive cognitive emotion-regulation strategies.

CONCLUSIONS

Addiction brain networks have potential for distinguishing IGD and RGU individuals. Importantly, this study identified novel gender-related differences in brain-behavior relationships in IGD. These results help advance current neuroscientific theories of IGD and may inform gender-informed treatment strategies.

Decreased modular segregation of the frontal-parietal network in major depressive disorder

Major depressive disorder (MDD) is a common psychiatric condition associated with aberrant large-scale distributed brain networks. However, it is unclear how the network dysfunction in MDD patients is characterized by imbalance or derangement of network modular segregation. Fifty-one MDD patients and forty-three matched healthy controls (HC) were recruited in the present study. We analyzed intrinsic brain activity derived from resting-state functional magnetic resonance imaging (R-fMRI) and then examined brain network segregation by computing the participation coefficient (PC). Further intra- and inter-modular connections analysis were preformed to explain atypical PC. Besides, we explored the potential relationship between the above graph theory measures and symptom severity in MDD. Lower modular segregation of the frontal-parietal network (FPN) was found in MDD compared with the HC group. The MDD group exhibited increased inter-module connections between the FPN and cingulo-opercular network (CON), between the FPN and cerebellum (Cere), between the CON and Cere. At the nodal level, the PC of the anterior prefrontal cortex, anterior cingulate cortex, inferior parietal lobule (IPL), and intraparietal sulcus showed larger in MDD. Additionally, the inter-module connections between the FPN and CON and the PC values of the IPL were negatively correlated with depression symptom in the MDD group. These findings might give evidence about abnormal FPN in MDD from the perspective of modular segregation in brain networks.

Relationship Between Gaming Disorder, Self-Compensation Motivation, Game Flow, Time Spent Gaming, and Fear of Missing Out Among a Sample of Chinese University Students: A Network Analysis

Background and Aims: In previous correlational research, the relationship between gaming disorder (GD), compensation motivation, game flow, time spent gaming, and fear of missing out (FoMO) has been examined. However, network analysis has rarely been applied to explore the relationship between GD, self-compensation motivation, game flow, time spent gaming, and FoMO. Therefore, the present study used network analysis to examine the relationship between the aforementioned variables among a sample of gamers. Methods: The present study comprised gamers (N = 1,635) recruited from three Chinese universities, who completed an online survey including the Gaming Disorder Test, Self-Compensation Motivation Questionnaire, Game Flow Questionnaire, and Trait-State Fear of Missing Out Scale, as well as four items related to time spent gaming. Results: Self-compensation motivation, game flow, time spent gaming, and FoMO were all significantly and positively associated with GD. In the domain-level and facet-level networks, weekday gaming hours and weekend gaming hours had the strongest edge intensity. The domain-level, facet-level, and item-level networks analysis also showed that GD was connected with self-compensation motivation, game flow, time spent gaming, and FoMO. The network structure demonstrated a significant difference between males and females (2.33 vs. 2.81, p = 0.001) using the domain-level network comparison test (NCT). Conclusions: The results suggest that GD is closely associated with self-compensation motivation, game flow, time spent gaming, and FoMO. FoMO and gaming motivation (i.e., self-compensation and game flow) may increase time spent gaming and facilitate GD. Therefore, interventions that decrease game immersion and time spent gaming are likely to decrease GD.

Development of functional connectivity within and among the resting-state networks in anesthetized rhesus monkeys

OBJECTIVE

The age-related changes in the resting-state networks (RSNs) exhibited temporally specific patterns in humans, and humans and rhesus monkeys have similar RSNs. We hypothesized that the RSNs in rhesus monkeys experienced similar developmental patterns as humans.

METHODS

We acquired resting-state fMRI data from 62 rhesus monkeys, which were divided into childhood, adolescence, and early adulthood groups. Group independent component analysis (ICA) was used to identify monkey RSNs. We detected the between-group differences in the RSNs and static, dynamic, and effective functional network connections (FNCs) using one-way variance analysis (ANOVA) and post-hoc analysis.

RESULTS

Eight rhesus RSNs were identified, including cerebellum (CN), left and right lateral visual (LVN and RVN), posterior default mode (pDMN), visuospatial (VSN), frontal (FN), salience (SN), and sensorimotor networks (SMN). In internal connections, the CN, SN, FN, and SMN mainly matured in early adulthood. The static FNCs associated with FN, SN, pDMN primarily experienced fast descending slow ascending type (U-shaped) developmental patterns for maturation, and the dynamic FNCs related to pDMN (RVN, CN, and SMN) and SMN (CN) were mature in early adulthood. The effective FNC results showed that the pDMN and VSN (stimulated), SN (inhibited), and FN (first inhibited then stimulated) chiefly matured in early adulthood.

CONCLUSION

We identified eight monkey RSNs, which exhibited similar development patterns as humans. All the RSNs and FNCs in monkeys were not widely changed but fine-tuned. Our study clarified that the progressive synchronization, exploration, and regulation of cognitive RSNs within the pDMN, FN, SN, and VSN denoted potential maturation of the RSNs throughout development. We confirmed the development patterns of RSNs and FNCs would support the use of monkeys as a best animal model for human brain function.

Dorsal and ventral striatal functional connectivity shifts play a potential role in internet gaming disorder

Animal models suggest transitions from non-addictive to addictive behavioral engagement are associated with ventral-to-dorsal striatal shifts. However, few studies have examined such features in humans, especially in internet gaming disorder (IGD), a proposed behavioral addiction. We recruited 418 subjects (174 with IGD; 244 with recreational game use (RGU)). Resting-state fMRI data were collected and functional connectivity analyses were performed based on ventral and dorsal striatal seeds. Correlations and follow-up spectrum dynamic causal model (spDCM) analyses were performed to examine relationships between the ventral/dorsal striatum and middle frontal gyrus (MFG). Longitudinal data were also analysed to investigate changes over time. IGD relative to RGU subjects showed lower ventral-striatum-to-MFG (mostly involving supplementary motor area (SMA)) and higher dorsal-striatum-to-MFG functional connectivity. spDCM revealed that left dorsal-striatum-to-MFG connectivity was correlated with IGD severity. Longitudinal data within IGD and RGU groups found greater dorsal striatal connectivity with the MFG in IGD versus RGU subjects. These findings suggest similar ventral-to-dorsal striatal shifts may operate in IGD and traditional addictions.

In order to shed light on the underlying neural mechanisms of internet gaming disorder (IGD), Dong et al collected longitudinal resting-state fMRI data from participants with IGD or those who partake in recreational game use. They demonstrated that, consistent with animal models of addiction, dorsal and ventral striatal functional connectivity shifts appeared to play a potential mechanistic role in IGD.

Sex difference in neural responses to gaming cues in Internet gaming disorder: Implications for why males are more vulnerable to cue-induced cravings than females

BACKGROUND

Although drug addiction studies have shown that females are more likely to become addicted and sensitive to drug cues, this feature seems reversed in Internet gaming disorder (IGD), of which males are more likely to be sufferers. Given the prevalence of IGD in the male population, the current study was set to examine the potential effect of sex on IGD's craving using a cue reactivity task.

METHODS

Sixty-five (32 males) IGD subjects underwent fMRI scanning during exposure to visual gaming cues and neutral cues. Brain responses to gaming cues relative to neutral cues were examined within two groups separately. In addition, Granger causal analysis (GCA) was conducted to investigate how the effective connectivity patterns were altered in male and female IGD subjects.

RESULTS

When facing gaming cues, lower regions of brain activation were observed in males compared to females, including the left anterior cingulate cortex (ACC), the superior frontal gyrus and the posterior cingulate cortex (PCC); GCA results, using the PCC as the ROI, showed higher middle temporal gyrus-PCC-right ACC/parahippocampal gyrus effective connectivity in males as compared with females, when exposed to gaming cues.

CONCLUSION

The results indicate that gaming cues could more severely disturb male IGD subjects' inhibition control function over game-elicited cravings compared to females, which might make it hard for males to control their game cravings and stop their gaming behaviors. This conclusion is valuable in understanding why males are more vulnerable to IGD than females.