Altered brain functional networks in people with Internet gaming disorder: Evidence from resting-state fMRI

Mindfulness Meditation Training Reduces Gaming Cravings by Reshaping the Functional Connectivity Between the Default Mode Network and Executive Control-Related Brain Regions

BACKGROUND

Internet gaming disorder (IGD) can lead to psychological problems and cause behavioral problems in individuals. Traditional interventions have been ineffective in treating IGD. Meanwhile, mindfulness meditation (MM) is an emerging method that has proven to be effective for treating psychiatric disorders. In this study, MM was used to intervene in IGD and to explore its neural mechanism.

METHODS

Eighty participants were recruited through advertisements. Eventually, 61 completed the 1-month training (MM group, n = 31; progressive muscle relaxation [PMR] group, n = 30), including a pretest, 8 training sessions, and a posttest. Regional homogeneity and degree centrality were calculated, and the tests (pre- and post-) and group (MM and PMR) analysis of variance was performed. The overlapping results were obtained as region of interest for functional connectivity (FC) analyses. Behavioral data and neurotransmitter availability maps were correlated with FC.

RESULTS

Compared with PMR, MM decreased the severity of addiction and game craving in IGD. Brain imaging results showed that the FC between and within the executive control and default mode networks/reward-related regions were enhanced. Significant negative correlations were observed between FC and dopamine receptor D2, dopamine transporter, and vesicular acetylcholine transporter. Significant positive correlations were observed between FCs and serotonin and aminobutyric acid receptors.

CONCLUSIONS

This study confirmed the effectiveness of MM in treating IGD. MM altered the default mode and enhanced top-down control over game cravings. These findings were revealed by the correlations between brain regions and behavioral and biochemical effects. The results show the neural mechanism of MM in reducing IGD and lay the foundation for future research.

Altered functional brain networks in problematic smartphone and social media use: resting-state fMRI study

Nowadays, the limitless availability to the World Wide Web can lead to general Internet misuse and dependence. Currently, smartphone and social media use belong to the most prevalent Internet-related behavioral addiction forms. However, the neurobiological background of these Internet-related behavioral addictions is not sufficiently explored. In this study, these addiction forms were assessed with self-reported questionnaires. Resting-state functional magnetic resonance imaging was acquired for all participants (n = 59, 29 males) to examine functional brain networks. The resting-state networks that were discovered using independent component analysis were analyzed to estimate within network differences. Significant negative associations with social media addiction and smartphone addiction were found in the language network, the lateral visual networks, the auditory network, the sensorimotor network, the executive network and the frontoparietal network. These results suggest that problematic smartphone and social media use are associated with sensory processing and higher cognitive functioning.

Resting-State Functional Magnetic Resonance Imaging as an Indicator of Neuropsychological Changes in Type 1 Narcolepsy

RATIONALE AND OBJECTIVES

To explore indicators of neuropsychological changes in patients with type 1 narcolepsy (NT1) using resting-state functional magnetic resonance imaging (rs-fMRI).

MATERIALS AND METHODS

Thirty-four NT1 patients and 34 age- and sex-matched healthy volunteers were recruited for neuropsychiatric assessments and rs-fMRI data acquisition. Fractional amplitude of low-frequency fluctuations (fALFF), regional homogeneity (ReHo), and related brain functional connectivity (FC) were calculated for the two groups and compared using a two-sample t test with cluster-level FDR correction. Moreover, partial correlation analysis was performed between these functional values of changed brain regions and clinical scales.

RESULTS

Compared to those of healthy controls, spontaneous functional activities were significantly weakened in patients with NT1 in regions such as the left/right posterior cerebellum lobe, left inferior temporal gyrus, and left dorsolateral superior frontal gyrus, whereas those in regions such as the left middle occipital gyrus, right inferior occipital gyrus, and left/right lingual gyrus were significantly strengthened. Furthermore, NT1 patients displayed significantly changed FCs between the left/right anterior cingulate gyrus (ACG) and regions such as the left/right cerebellum, left middle occipital gyrus, and left inferior frontal gyrus in the operculum. In partial correlation analysis, the functions in the left dorsolateral superior frontal gyrus were significantly related to the Trail Making Tests (TMT) score. Moreover, the FC between the left ACG and left inferior frontal gyrus in the operculum was highly correlated with anxiety and depression features, including the Hamilton Anxiety Scale (HAMA) score and Hamilton Depression Rating Scale (HAMD-17) score.

CONCLUSION

Patients with NT1 exhibited abnormalities in the anterior cingulate cortex, frontal-parietal cortex, hippocampus, and left/right posterior cerebellum lobe. The deactivation of the left frontal-temporal cortex is stronger, which is involved in the cognitive decline and mental disorders in these patients. Damage to the ACG may affect its FC with other regions and cause cognition and emotion dysregulation, perhaps by impairing patients' visual pathways and frontal-temporal-parietal networks. Hence, these could be important biomarkers for their neuropsychological changes.

Effective connectivity analysis of verbal working memory advantage across materials for pathological smartphone users by fNIRS

Previous studies have found working memory (WM) advantages of the pathological smartphone use (PSU) group, but most of which were emphasized in the network-related domain. Whether the advantages can transfer to other domains has yet to be confirmed. In particular, exploring from a brain mechanism perspective is necessary. Using the classical N-back paradigm, this study selected network-related words and neutral words as materials combined with fNIRS to probe the verbal WM characteristics of the PSU group. The results showed that β in channel 3, channel 4, and channel 5 were significantly lower in the PSU group than those in the control group The analysis of the region of interest revealed that the PSU group showed significantly lower β in the l-DLPFC and frontopolar. Granger Causality results showed that functional connectivity between frontopolar and R-DLPFC for the PSU group was significantly higher than for the control group in the network word condition. These results demonstrate that the PSU group has an advantage in WM, transferring from the network-related stimulus to the neutral stimulus. The advantages of network stimulus were related to bidirectional connectivity between frontopolar and R-DLPFC. Also, the l-DLPFC and frontopolar are associated with the cross-material consistency of WM.

Working memory performance in disordered gambling and gaming: A systematic review

BACKGROUND

Converging evidence supports that gaming and gambling disorders are associated with executive dysfunction. The involvement of different components of executive functions (EF) in these forms of behavioural addiction is unclear.

AIM

In a systematic review, we aim to uncover the association between working memory (WM), a crucial component of EF, and disordered gaming and gambling. Note that, in the context of this review, gaming has been used synonymously with video gaming.

METHODS

Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we systematically searched for studies published from 2012 onwards.

RESULTS

The search yielded 6081 records after removing duplicates, from which 17 peer-reviewed journal articles were eligible for inclusion. The association between WM and problem or disordered gaming and gambling have been categorized separately to observe possible differences. Essentially, problem gaming or gambling, compared to disorder, presents lesser severity and clinical significance. The results demonstrate reduced auditory-verbal WM in individuals with gambling disorder. Decreased WM capacity was also associated with problem gambling, with a correlation between problem gambling severity and decreased WM capacity. Similarly, gaming disorder was associated with decreased WM. Specifically, gaming disorder patients had lower WM capacity than the healthy controls.

CONCLUSION

Working memory seems to be a significant predictor of gambling and gaming disorders. Therefore, holistic treatment approaches that incorporate cognitive techniques that could enhance working memory may significantly boost gambling and gaming disorders treatment success.

Impulsivity-related right superior frontal gyrus as a biomarker of internet gaming disorder

Background

Internet gaming disorder (IGD) is a mental health issue that affects individuals worldwide. However, the lack of knowledge about the biomarkers associated with the development of IGD has restricted the diagnosis and treatment of this disorder.

Aims

We aimed to reveal the biomarkers associated with the development of IGD through resting-state brain network analysis and provide clues for the diagnosis and treatment of IGD.

Methods

Twenty-six patients with IGD, 23 excessive internet game users (EIUs) who recurrently played internet games but were not diagnosed with IGD and 29 healthy controls (HCs) performed delay discounting task (DDT) and Iowa gambling task (IGT). Resting-state functional magnetic resonance imaging (fMRI) data were also collected.

Results

Patients with IGD exhibited significantly lower hubness in the right medial orbital part of the superior frontal gyrus (ORBsupmed) than both the EIU and the HC groups. Additionally, the hubness of the right ORBsupmed was found to be positively correlated with the highest excessive internet gaming degree during the past year in the EIU group but not the IGD group; this might be the protective mechanism that prevents EIUs from becoming addicted to internet games. Moreover, the hubness of the right ORBsupmed was found to be related to the treatment outcome of patients with IGD, with higher hubness of this region indicating better recovery when undergoing forced abstinence. Further modelling analysis of the DDT and IGT showed that patients with IGD displayed higher impulsivity during the decision-making process, and impulsivity-related parameters were negatively correlated with the hubness of right ORBsupmed.

Conclusions

Our findings revealed that the impulsivity-related right ORBsupmed hubness could serve as a potential biomarker of IGD and provide clues for the diagnosis and treatment of IGD.

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.

Altered effective connectivity from the pregenual anterior cingulate cortex to the laterobasal amygdala mediates the relationship between internet gaming disorder and loneliness

BACKGROUND

Individual with internet gaming disorder (IGD) often experience a high level of loneliness, and neuroimaging studies have demonstrated that amygdala function is associated with both IGD and loneliness. However, the neurobiological basis underlying these relationships remains unclear.

METHODS

In the current study, Granger causal analysis was performed to investigate amygdalar subdivision-based resting-state effective connectivity differences between 111 IGD subjects and 120 matched participants with recreational game use (RGUs). We further correlated neuroimaging findings with clinical measures. Mediation analysis was conducted to explore whether amygdalar subdivision-based effective connectivity mediated the relationship between IGD severity and loneliness.

RESULTS

Compared with RGUs, IGD subjects showed inhibitory effective connections from the left pregenual anterior cingulate cortex (pACC) to the left laterobasal amygdala (LBA) and from the right medial prefrontal cortex (mPFC) to the left LBA, as well as an excitatory effective connection from the left middle prefrontal gyrus (MFG) to the right superficial amygdala. Further analyses demonstrated that the left pACC-left LBA effective connection was negatively correlated with both Internet Addiction Test and UCLA Loneliness scores, and it mediated the relationship between the two.

CONCLUSION

IGD subjects and RGUs showed different connectivity patterns involving amygdalar subdivisions. These findings support a neurobiological mechanism for the relationship between IGD and loneliness, and suggest targets for therapeutic approaches that could be used to treat IGD.

Developmental Assets, Self-Control and Internet Gaming Disorder in Adolescence: Testing a Moderated Mediation Model in a Longitudinal Study

From the perspective of positive youth development, developmental assets and self-control play critical roles in promoting adolescent development. However, their effects have not been evaluated in the current issue, internet gaming disorder (IGD). IGD is gradually becoming an important social problem among worldwide youth and has been included in the eleventh International Classification of Diseases (ICD-11). Therefore, the present study was determined to investigate the relationship between developmental assets, self-control, and IGD. A two-wave longitudinal study, with each wave spanning half a year apart, was conducted in a sample of 1023 adolescents (aging from 11 to 15, 49.36% boys) during the COVID-19 pandemic. Results of the moderated mediation model revealed that T1 developmental assets could predict less IGD at T2 directly or through T1 self-control indirectly. Furthermore, the moderating effect of gender was not significant in the mediation model. Overall, adolescents who experience more developmental assets are less likely to suffer IGD. Moreover, developmental assets are conducive to developing a higher level of self-control, which in turn contributes to preventing or intervening in IGD as well. Therefore, measures should be taken to construct developmental assets to prevent or reduce IGD during adolescence.

Topological Alterations of Working Memory Impairment in Aged Patients With Vascular Dementia

Aneurysmal subarachnoid hemorrhage (aSAH) is a common disease causing vascular dementia. Survivors often suffer from cognitive impairment especially working memory deficit. Currently, lack of theoretical support limits the improvement of cognitive intervention or rehabilitation. It is unclear how the large-scale network differs and to what extent is the brain network affected? Our study aims to provide novel information about the topological characteristics of brain organization, especially "small-world" property. A total of 62 aSAH patients are enrolled in this study. They are divided into two groups according to the syndrome of working memory deficit. Their working memory function is evaluated by TMT-B and AVLT (Chinese version). Functional MRI scan is also performed for detecting resting-state cortical plasticity. We utilized ICA to extract functional sub-networks including working memory network from imaging data. And then we establish binarized network and calculate the small-worldness property as well as local and global efficiency of networks. aSAH group with working memory deficit shows no significant difference of clustering coefficient with control group. Our study discovered significant decrease of characteristic path length indicating an increase of overall routing efficiency. We reason that patients with working memory deficit have to recruit more neuronal resources and thus develops higher overall routing efficiency of local network. This study provides novel information about the neural alterations of aSAH patients with working memory deficit. It might contribute to the understanding of neural mechanism and the improvement of current intervention for vascular dementia.

Neurobiological mechanisms underlying internet gaming disorder

This review summarizes studies on the neurobiological correlates of internet gaming disorder (IGD), presently the most direct approach to analyzing the impact of digital technology and the internet on brain mechanisms. Brain imaging studies have shown that IGD shares, to a large extent, neurobiological alterations that are typical for other addictions, such as: (i) activation in brain regions associated with reward, as evident from cue exposure and craving studies and neurotransmitter systems studies that indicate an involvement of dopamine-mediated reward mechanisms; (ii) reduced activity in impulse control areas and impaired decision making; and (iii) reduced functional connectivity in brain networks that are involved in cognitive control, executive function, motivation, and reward. Moreover, there are structural changes, mainly reduction in gray-matter volume and white-matter density. Comorbidity studies indicate that executive control networks in attention deficit-hyperactivity disorder (ADHD) may increase the susceptibility to develop IGD. Most importantly, this review also outlines findings that show the effects of excessive use of screens, here referring to the playing of computer games, which activate many brain regions associated with cognitive, motor, and sensory function and not directly involved in other forms of addiction. This review describes and summarizes comprehensively the neurobiological correlates of addictive internet use in adolescents and young adults.
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Large-scale network dysfunction in youths with Internet gaming disorder: a meta-analysis of resting-state functional connectivity studies

Internet gaming disorder (IGD) has been defined as a specific behavioral disorder, associated with abnormal interactions among large-scale brain networks. Researchers have sought to identify the network dysfunction in IGD using resting-state functional connectivity (rsFC). However, results across studies have not reached an agreement yet and the mechanism remains unclear. The present research aimed to investigate network dysfunction in IGD through a meta-analysis of rsFC studies. Twenty-two seed-based voxel-wise rsFC studies from 25 publications (594 individuals with IGD and 496 healthy controls) were included. By categorizing seeds into seed-networks based on their location within a prior functional network parcellations, we performed a Multilevel kernel density analysis (MKDA) within each seed-network to identify which brain systems showed abnormal interaction with particular seed-network in individuals with IGD. Compared to healthy control groups, individuals with IGD exhibited significant hypoconnectivity within the default mode network, and enhanced connectivity between the default mode network and insula within the ventral attention network. IGD was also associated with increased connectivity between the ventral attention network and somatomotor regions. Furthermore, the IGD groups showed hyperconnectivity between the limbic network and regions of the frontoparietal network. The results suggest that individuals with IGD show large-scale functional network alteration which underpins their core symptoms including poor emotional competence, cue-reactivity and craving, habitual addictive behaviors and impaired executive control. Whether the compensation mechanism exists in IGD is discussed, and further research is needed. The findings provide a neurocognitive network model of IGD, which may serve as functional biomarkers for IGD and have potentials for development of effective diagnosis and therapeutic interventions.

Altered modular segregation of brain networks during the cue-craving task contributes to the disrupted executive functions in internet gaming disorder

BACKGROUND

Previous studies have shown that gaming-related cues could induce gaming cravings and bring about changes in brain activities in subjects with Internet gaming disorder (IGD). However, little is known about the brain network organizations in IGD subjects during a cue-craving task and the relationship between this network organization and IGD severity.

METHODS

Sixty-one IGD subjects and 61 matched recreational game users (RGUs) were scanned while performing a cue-craving task. We calculated and compared the participation coefficient (PC) among brain network modules between IGD subjects and RGUs. Based on the results, further group comparison analyses were performed to explain the PC changes and to explore the relationship between PCs and IGD severity.

RESULTS

While performing a cue-craving task, compared with RGUs, IGD subjects showed significantly decreased PCs in the default-mode network (DMN) and the frontal-parietal network (FPN). Specifically, the number of connections between nodes in the ventromedial prefrontal cortex, anterior cingulate cortex, posterior cingulate cortex and other nodes in the DMN of IGD subjects was much larger than that in RGUs. Correlation results showed that the number of DMN intra-modular connections was positively correlated with addiction severity and craving degree.

CONCLUSIONS

These results provide neural evidence that can explain why cognitive control, emotion, attention and other functions are impaired in IGD subjects in the face of gaming cues, which leads to compulsive behavior toward games. These findings extend our understanding of the neural mechanism of IGD and have important implications for developing effective interventions to treat IGD subjects.

Functional Organization of Brain Network in Peripheral Neural Anastomosis Rats after Electroacupuncture: An ICA and Connectome Analysis

Acupuncture is a mild therapy in rehabilitation practice of peripheral nerve injury. Previous studies confirmed the deep participation of brain plasticity in the process of functional restoration. The therapeutic effect of acupuncture is also believed to be closely associated with brain plasticity, especially in the hypothalamus and limbic system. But the fuzzy neural mechanism somehow limits the application or improvement of this therapy. There is little information about the effect of acupuncture on topological properties of brain networks. Instead of functional segregation approach, we utilized graph theory method to analyze the large-scale and distributed properties of information processing. We first established rat model of sciatic nerve injury and performed rehabilitation therapy of electroacupuncture for 120 days. Meanwhile, we used independent component analysis to extract seven sub-networks from the whole brain. Then measurements of graph theory were calculated in each sub-network as well as the whole brain network. We found no significant difference of any measurement in whole brain network among intervention group, model group and normal group. But the assortativity, hierarchy, small-world properties of sub-network displayed significant differences among three groups. It induces changes of neural plasticity in several sub-networks instead of whole brain network. We attributed the changes to the enhancement of the short-term compensatory adaptation and the reduction of the long-term overacting regional information transmission. The present study may shed light on the vague distinction of large-scale property of brain networks after electroacupuncture, which leads to a better understanding of this ancient traditional Chinese therapy.

Brain Network Constancy and Participant Recognition: an Integrated Approach to Big Data and Complex Network Analysis

With the development of big data sharing and data standardization, electroencephalogram (EEG) data are increasingly used in the exploration of human cognitive behavior. Most of the existing studies focus on the changes of human brain network topology (the number of connections, degree distribution, clustering coefficient phantom) in various cognitive behaviors. However, there has been little exploration into the steady state of multi-cognitive behaviors and the recognition of multi-participant brain networks. To solve these two problems, we used EEG data of 99 healthy participants from the PhysioBank to study multi-cognitive behaviors. Specifically, we calculated the symbolic transfer entropy (STE) between 64 electrode sequences of EEG data and constructed the brain networks of various cognitive behaviors of each participant using the directed minimum spanning tree (DMST) algorithm. We then investigated the eigenvalue spectrum of the STE matrix of each individual's cognitive behavior. The results also showed that the spectrum distributions of different cognitive states of the same participant remained relatively stable, but those of the same cognitive state of different participants varied considerably, verifying the relative stability and uniqueness of the human brain network similar to a human's fingerprint. Based on these features, we used the spectral distribution set of 99 participants of various cognitive states as the original data set and developed a spectral distribution set scoring (SDSS) method to identify the brain network participants. It was found that most labels (69.35%) of the test participant with the highest score were identical to the labeled participant. This study provided further evidence for the existence of human brain fingerprints, and furnished a new approach for dynamic identification of brain fingerprints.

Neurobiological influence of comorbid conditions in young patients diagnosed with gaming disorder: A whole-brain functional connectivity study based on a data driven method

Gaming disorder, which is characterized by multiple cognitive and behavioral symptoms, often has comorbid psychiatric conditions such as depression and attention-deficit hyperactivity disorder. Neurobiological effects of the comorbid disorders so far reported are not converging, exhibiting positive and negative alterations of the connectivity in brain networks. In this study, we conducted resting-state functional magnetic-resonance imaging and whole brain functional connectivity analyses for young participants consisting of 40 patients diagnosed with the gaming disorder, with and without comorbid conditions, and 29 healthy controls. Compared to healthy controls, the gaming disorder-alone patients had partially diminished connectivities in the reward system and executive control network, within which there existed central nodes that served as a hub of diminished connections. In the gaming disorder patients who had comorbidity of autism spectrum disorder, the diminished connections were enlarged, with alteration of the hub nodes, to the entire brain areas involved in the reward system including cortical, subcortical and limbic areas that are crucial for reward processing, and to the whole cortical areas composing the executive control network. These observations suggest that the neurodevelopmental condition coexisting with the gaming disorder induced substantial impairment of the neural organizations associated with executive/cognitive and emotional functions, which are plausibly causal to the behavioral addiction, by rearranging and diminishing functional connectivities in the network.

Altered coupling of default-mode, executive-control and salience networks in Internet gaming disorder

Background:

Recently, a triple-network model suggested the abnormal interactions between the executive-control network (ECN), default-mode network (DMN) and salience network (SN) are important characteristics of addiction, in which the SN plays a critical role in allocating attentional resources toward the ECN and DMN. Although increasing studies have reported dysfunctions in these brain networks in Internet gaming disorder (IGD), interactions between these networks, particularly in the context of the triple-network model, have not been investigated in IGD. Thus, we aimed to assess alterations in the inter-network interactions of these large-scale networks in IGD, and to associate the alterations with IGD-related behaviors.

Methods:

DMN, ECN and SN were identified using group-level independent component analysis (gICA) in 39 individuals with IGD and 34 age and gender matched healthy controls (HCs). Then alterations in the SN-ECN and SN-DMN connectivity, as well as in the modulation of ECN versus DMN by SN, using a resource allocation index (RAI) developed and validated previously in nicotine addiction, were assessed. Further, associations between these altered network coupling and clinical assessments were also examined.

Results:

Compared with HCs, IGD had significantly increased SN-DMN connectivity and decreased RAI in right hemisphere (rRAI), and the rRAI in IGD was negatively associated with their scores of craving.

Conclusions:

These findings suggest that the deficient modulation of ECN versus DMN by SN might provide a mechanistic framework to better understand the neural basis of IGD and might provide novel evidence for the triple-network model in IGD.

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.

Alterations in Amygdala Connectivity in Internet Addiction Disorder

Recent studies have revealed structural and functional abnormalities in amygdala due to Internet addiction (IA) associated with emotional disturbance. However, the role of amygdala connectivity that is responsible for emotion-cognition interactions is largely unknown in IA. This study aims to explore the amygdala connectivity abnormalities in IA. The functional and structural connectivity of bilateral amygdala were examined using seed-based connectivity analysis, and the structural integrity on white mater tracts passing through amygdala was also examined. Additionally, a correlation analysis was performed to investigate the relationship between brain connectivity and duration of IA. We found that IA subjects had decreased negative functional connectivity (FC) between amygdala and dorsolateral prefrontal cortex (DLPFC), and had increased negative FC between amygdala and precuneus and superior occipital gyrus (SOG). While IA subjects had decreased positive FC between amygdala and anterior cingulate cortex (ACC), and had increased positive FC between amygdala and thalamus. The FC between left amygdala and right DLPFC had significant correlation with duration of IA. The structural connectivity and integrity between amygdala and ACC were also decreased in IA subjects. These findings indicate that the amygdala connectivity is altered in IA subjects. The altered FC of amygdala-DLPFC is associated with duration of IA.

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.

Alterations in the connection topology of brain structural networks in Internet gaming addiction

Internet gaming addiction (IGA), as the most popular subtype of Internet addiction, is becoming a common and widespread mental health concern, but there are still debates on whether IGA constitutes a psychiatric disorder. The view on the brain as a complex network has developed network analysis of neuroimaging data, revealing that abnormalities of brain functional and structural systems are related to alterations in brain network configuration, such as small-world topology, in neuropsychiatric disorders. Here we applied network analysis to diffusion-weighted MRI data of 102 gaming individuals and 41 non-gaming healthy individuals to seek changes in the small-world topology of brain structural networks in IGA. The connection topology of brain structural networks shifted to the direction of random topology in the gaming individuals, irrespective of whether they were diagnosed with Internet gaming disorder. Furthermore, when we simulated targeted or untargeted attacks on nodes, the connection topology of the gaming individuals' brain structural networks under no attacks was comparable to that of the non-gaming healthy individuals' brain structural networks under targeted attacks. Alterations in connection topology provide a clue that Internet gaming addicted brains could be as abnormal as brains suffering from targeted damage.

Group independent component analysis reveals alternation of right executive control network in Internet gaming disorder

OBJECTIVE

Previous studies have demonstrated that individuals with Internet gaming disorder (IGD) showed attentional bias toward gaming-related cues and exhibited impaired executive functions. The purpose of this study was to explore the alternations in related functional brain networks underlying attentional bias in IGD subjects.

METHODS

Eighteen IGD subjects and 19 healthy controls (HC) were scanned with functional magnetic resonance imaging while they were performing an addiction Stroop task. Networks of functional connectivity were identified using group independent component analysis (ICA).

RESULTS

ICA identified 4 functional networks that showed differences between the 2 groups, which were related to the right executive control network and visual related networks in our study. Within the right executive control network, in contrast to controls, IGD subjects showed increased functional connectivity in the temporal gyrus and frontal gyrus, and reduced functional connectivity in the posterior cingulate cortex, temporal gyrus, and frontal gyrus.

CONCLUSION

These findings suggest that IGD is related to abnormal functional connectivity of the right executive control network, and may be described as addiction-related abnormally increased cognitive control processing and diminished response inhibition during an addiction Stroop task. The results suggest that IGD subjects show increased susceptibility towards gaming-related cues but weakened strength of inhibitory control.

Disrupted brain network topology in chronic insomnia disorder: A resting-state fMRI study

This study investigated the topological characteristics of brain functional networks in chronic insomnia disorder (CID) patients. The resting-state functional magnetic resonance imaging and graph theory analysis method were applied to investigate the brain functional connectome patterns among 45 CID patients and 32 healthy controls. The brain functional connectome was constructed by thresholding partial correlation matrices of 90 brain regions from an automated anatomical labeling atlas. The topologic properties of brain functional connectomes at both global and nodal levels were tested. The CID patients had decreased number of module (p = .014) and hierarchy (p = .038), and increased assortativity (p = .035). Furthermore, some brain regions located in the default mode network, dorsal attention network, and sensory-motor network in these patients showed altered nodal centralities. Within these areas, the node betweenness of right central paracentral lobule had positive correlation with the Pittsburgh Sleep Quality Index score (R = 0.319, p = .039). The results imply that functional disruptions of CID patients may be related to disruptions in global and regional topological organization of the brain functional connectome, and provide new and important insights to understand the pathophysiological mechanisms of CID.

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Chronic insomnia disorder (CID) patients had disrupted global topological properties.

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Many brain regions of CID patients showed altered nodal centralities involving three different resting networks.

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Functional disruption of right central paracentral lobule may be a target for therapeutic intervention in pediatric CID.

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The disruption of topological organization might be explain the mechanism/reason of functional disruptions of CID.

Longitudinal Changes in Neural Connectivity in Patients With Internet Gaming Disorder: A Resting-State EEG Coherence Study

Aims: The present study investigated neural connectivity associated with treatment responses in patients with Internet gaming disorder (IGD) using resting-state electroencephalography (EEG) coherence analyses. Methods: We included 30 patients with IGD and 32 healthy control subjects (HCs). Of the IGD patients, 18 completed an outpatient treatment that included pharmacotherapy with selective serotonin reuptake inhibitors for 6 months. Resting-state EEG coherence and self-report questionnaires were used to evaluate clinical and psychological features pre- and post-treatment, and data were analyzed using generalized estimating equations. Results: Compared with HCs, patients with IGD showed increased beta and gamma intrahemispheric coherence and increased delta intrahemispheric coherence of the right hemisphere at baseline. After 6 months of outpatient management, patients with IGD exhibited improvements in IGD symptoms compared with baseline, but they continued to show increased beta and gamma intrahemispheric coherence compared with that of HCs. No significant EEG coherence changes between the pre- and post-treatment assessments were detected in any band in the IGD group. Conclusion: These findings suggest that significantly greater intrahemispheric fast-frequency coherence may be an important neurophysiological trait marker of patients with IGD.

Altered Brain Activities Associated with Craving and Cue Reactivity in People with Internet Gaming Disorder: Evidence from the Comparison with Recreational Internet Game Users

Although the neural substrates of cue reactivity in Internet gaming disorder (IGD) have been examined in previous studies, most of these studies focused on the comparison between IGD subjects and healthy controls, which cannot exclude a potential effect of cue-familiarity. To overcome this limitation, the current study focuses on the comparison between IGD subjects and recreational Internet game users (RGU) who play online games recreationally but do not develop dependence. Data from 40 RGU and 30 IGD subjects were collected while they were performing an event-related cue reactivity task in the fMRI scanner. The results showed that the IGD subjects were associated with enhanced activation in the left orbitofrontal cortex (OFC) and decreased activation in the right anterior cingulate cortex (ACC), right precuneus, left precentral gyrus and right postcentral gyrus in comparison with the RGU subjects. OFC is involved in reward evaluation and ACC is implicated in executive control function based on previous researches. Moreover, the activation of OFC were correlated with the desire for game-playing. Thus, the higher activation in OFC might suggests high desire for game playing, and the lower activation in ACC might indicates impaired ability in inhibiting the urge to gaming-related stimuli in IGD subjects. Additionally, decreased activation in the precuneus, the precentral and postcentral gyrus may suggest the deficit in disentangling from game-playing stimuli. These findings explain why IGD subjects develop dependence on game-playing while RGU subjects can play online games recreationally and prevent the transition from voluntary game-playing to eventually IGD.

The correlation between mood states and functional connectivity within the default mode network can differentiate Internet gaming disorder from healthy controls

The default-mode network (DMN) has been suggested to support a baseline state of brain activity. However, whether connectivity within the DMN is associated with mood states remains incompletely understood. The current study examined the correlation between mood state and the functional connectivity (FC) among DMN regions, and examined if the FC can differentiate Internet gaming disorder (IGD) from healthy controls (HC). Resting state data were collected within 108 college students (IGD,41; HC,67). Negative correlations were observed between measures of: (1) Depression and FCs among ventral DMN regions; (2) Anger and FCs among dorsal DMN regions; and, (3) Anger and Depression and FCs of both the ventral and dorsal DMN. The results suggest that negative mood states of Depression and Anger might reflect poorer, or might impair, FCs among DMN regions. In addition, the FC among DMNs could be useful indexes in differencing IGD from HC. Future studies should examine the extent to which the findings may extend to clinical populations and whether increased connectivity of DMN regions may represent a mechanism for reducing negative mood states.

An Update Overview on Brain Imaging Studies of Internet Gaming Disorder

There are a growing number of studies on structural and functional brain mechanisms underlying Internet gaming disorder (IGD). Recent functional magnetic resonance imaging studies showed that IGD adolescents and adults had reduced gray matter volume in regions associated with attention motor coordination executive function and perception. Adolescents with IGD showed lower white matter (WM) integrity measures in several brain regions that are involved in decision-making, behavioral inhibition, and emotional regulation. IGD adolescents had also disruption in the functional connectivity in areas responsible for learning memory and executive function, processing of auditory, visual, and somatosensory stimuli and relay of sensory and motor signals. IGD adolescents also had decreased functional connectivity of PFC-striatal circuits, increased risk-taking choices, and impaired ability to control their impulses similar to other impulse control disorders. Recent studies indicated that altered executive control mechanisms in attention deficit hyperactivity disorder (ADHD) would be a predisposition for developing IGD. Finally, patients with IGD have also shown an increased functional connectivity of several executive control brain regions that may related to comorbidity with ADHD and depression. The behavioral addiction model argues that IGD shows the features of excessive use despite adverse consequences, withdrawal phenomena, and tolerance that characterize substance use disorders. The evidence supports the behavioral addiction model of IGD by showing structural and functional changes in the mechanisms of reward and craving (but not withdrawal) in IGD. Future studies need to investigate WM density and functional connectivity in IGD in order to validate these findings. Furthermore, more research is required about the similarity in neurochemical and neurocognitive brain circuits in IGD and comorbid conditions such as ADHD and depression.