Gender difference in network relationship between inter-temporal decisions and prefrontal activation levels in internet gaming disorder.

Background: Impulsivity and decision-making are key factors in addiction. However, little is known about how gender and time sensitivity affect impulsivity in internet gaming disorder (IGD). Objective: To investigate the gender difference of impulsive decision-making and relevant brain responses in IGD. Methods: We conducted a functional magnetic resonance imaging (fMRI) study with 123 participants, including 59 IGD individuals (26 females) and 64 matched recreational game users (RGUs, 23 females). Participants performed a delay-discounting task during fMRI scanning. We examined gender-by-group effects on behavioral and neural measures to explore the preference for immediate over delayed rewards and the associated brain activity. We also investigated the network correlations between addiction severity and behavioral and neural measures, and analyzed the mediating role of brain activity in the link between delay discounting parameters and IGD severity. Results: We found significant gender-by-group interactions. The imaging results revealed gender-by-group interactions in the dorsolateral prefrontal cortex, medial frontal gyrus, and inferior frontal gyrus (IFG). Post hoc analysis indicated that, for females, RGUs showed higher activity than IGD individuals in these brain regions, while for males IGD individuals exhibited higher activity than RGUs. The activation in the left IFG mediated the relation between Internet Addiction Test score and discount rate in females. In males, the activation in the right dlPFC mediated the relation between IAT score and time sensitivity. Discussion: Our findings imply that male IGD participants demonstrate impaired intertemporal decisions associated with neural dysfunction. Influencing factors for impulsive decision-making in IGD diverge between males (time sensitivity) and females (discount rate). These findings augment our comprehension of the neural underpinnings of gender differences in IGD and bear significant implications for devising effective intervention strategies for treating people with IGD.

Similarities and differences between internet gaming disorder and tobacco use disorder: A large-scale network study.

Studies have shown that internet gaming disorder (IGD) has the potential to be a type of addiction; however, direct comparisons (similarities and differences) between IGD and traditional addictions remain scarce, especially at the neuroimaging level. Resting-state functional magnetic resonance imaging (fMRI) data were collected from 92 individuals with IGD, 96 individuals with tobacco use disorders (TUDs) and 107 individuals who served as healthy controls (HCs). Independent component analysis (ICA) was performed to explore the similarities and differences among these three groups; Granger causality analysis (GCA) was further performed based on the ICA results to determine potential neural features underlying the differences and similarities among the groups. The ICA results indicated significant differences in the subcortical network and cerebellar network. GCA results found that significant differences in bilateral caudate among three groups, and the efferents of dorsal frontostriatal circuit showed significant differences in insula among three groups, whereas efferents of ventral frontostriatal circuit showed significant differences in the medial prefrontal cortex (mPFC). Two kinds of addiction showed differences in thalamus and frontostriatal circuits, and similar changes found in cerebellum and mPFC regions. It suggested that addiction disorders have psychopathology features, and the craving and reward dysfunctions may be the key reasons. Although both substance addiction and behaviour addiction showed craving dysfunction in cerebellum, however, the key reward dysfunction of substance addiction was found in subcortical regions, whereas behaviour addiction located in cortical regions.

Imbalanced sensitivities to primary and secondary rewards in internet gaming disorder.

BACKGROUND: Internet gaming disorder (IGD) is a type of behavioral addiction characterized by poorly controlled and interfering patterns of game playing. Studies have suggested that the IGD is usually accompanied by increased desire or craving for gaming, suggesting that secondary rewards related to gaming may become more salient than those for primary rewards like food. However, this hypothesis has not been formally tested and potential neural mechanisms remain unclear. METHODS: This is a functional magnetic resonance imaging (fMRI) study. Twenty-one IGD subjects and 23 matched individuals with recreational game use (RGU) were scanned when exposed to gaming (secondary rewards), food (primary rewards) and neutral cues. Group-by-cue-type interaction analyses and subsequent within-group analyses for fMRI data were performed and seed-based functional connectivity (FC) analyses explored further potential neural features. RESULTS: IGD subjects' subjective craving responses to gaming cues were higher than to food cues, while the opposite was observed in RGU subjects. Group-by-cue interaction effects implicated the precuneus and precuneus-caudate FC. Simple effect analysis showed that for IGD subjects, gaming-related cues elicited higher FC in precuneus-caudate relationships than did food-related cues. In the RGU subjects, the opposite was observed. Significant correlations were found between brain features and craving scores. CONCLUSIONS: These results support the hypothesis regarding imbalances in sensitivities to different types of reward in IGD, and suggest neural mechanisms by which craving for gaming may make secondary rewards more salient than primary ones, thus promoting participation in addictive patterns of gaming.