Brain responses to decision-making in easy and hard choices in internet gaming disorder: Implications for irrepressible gaming behaviours

Differential neural reward processes in internet addiction: A systematic review of brain imaging research

OBJECTIVES

This systematic review aims to examine the neural correlates of reward processing in various forms of Internet Addiction (IA) among adults, including generalized IA and specific conditions such as Internet Gaming Disorder (IGD). The study seeks to identify distinct patterns of altered connectivity and activation in reward-related brain regions across different IA subtypes.

METHODS

We analyzed findings from 44 neuroimaging studies, aligning with the Research Domain Criteria (RDoC) framework. The review focused on three key aspects of reward processing: responsiveness, learning, and valuation. Studies included both structural and functional neuroimaging data from adult populations with various forms of IA.

RESULTS

Findings suggest distinct patterns of altered connectivity and activation in reward-related brain regions across different IA subtypes. IGD is associated with widespread abnormalities in both structural and functional connectivity within the reward network, whereas excess social media use primarily affects the amygdala-striatal system. However, methodological limitations, including variability in IA definitions, lack of comparative studies between IA subtypes, and predominance of cross-sectional designs, hinder definitive conclusions.

CONCLUSION

This review underscores the need for a nuanced approach to IA, recognizing potentially distinct neural mechanisms across subtypes. Such insights could inform the development of targeted interventions and enhance the clinical utility of IA research and treatment. Future research should address current methodological limitations to provide more definitive conclusions about the neurobiological underpinnings of various forms of IA.

Influence of reinforcement learning on the inhibitory control of Internet gaming disorder

Reward processing dysfunction and inhibition control deficiency have been observed in Internet gaming disorder (IGD). However, it is still unclear whether the previous reinforcement learning depends on reward/punishment feedback influences on the cognitive inhibitory control of IGD. This study compared the differences between an IGD group and healthy people without game experiences in the probability selection task and the subsequent stop signal task by the method of behavioral experiments, in order to explore whether the reward learning ability is impaired in the IGD group. We also discuss the influence of previous reward learning on subsequent inhibition control. The results showed that (1) during the reward learning phase, the IGD group's accuracy was significantly lower than that of the control group; (2) compared with the control group, the IGD group's reaction times were longer in the transfer phase; (3) for no-go trials of the inhibitory control phase after reward learning, the accuracy of the reward-related stimulation in the IGD group was lower than that of punishment-related or neutral stimulation, but there was no significant difference among the three conditions in the control group. These findings indicated that the reinforcement learning ability of the IGD group was impaired, which further caused the abnormal response to reinforcement stimuli.

An Empirical Investigation of the Relationships Among Self-Esteem, Depression and Self-Serving Bias in People with Internet Gaming Disorder

Introduction

People are generally characterized by a self-serving bias which describes the tendency to ascribe positive outcomes or success to internal or personal causes (self-enhancement motivation) and ascribe negative outcomes or failure to external or situational causes (self-protection motivation). It has been found that the individuals with internet gaming disorder (IGD) who have low self-esteem and high depression exhibit an attenuated self-serving bias. However, the relationships among self-esteem, depression and self-serving bias are not clearly identified.

Methods

A sample of 138 IGD participants completed self-esteem and depression scales and a causal attribution task (Study 1) to examine the relationships among self-esteem, depression and self-serving bias (both self-enhancement and self-protection). In follow-up Study 2, 28 IGD participants were recruited to undertake self-affirmation intervention which can affirm one's sense of global self-view and bolster self-esteem to explore whether self-affirmation would trigger a reduction of depression and a raise of self-serving bias.

Results

The results of path analysis in Study 1 showed that the self-serving bias was predicted by self-esteem and depression, and the depression played a mediating role between self-esteem and self-serving bias. The results of Study 2 showed that the IGD participants reported higher self-esteem, lower depression and engaged in more self-protection motivation after affirming-self manipulation as compared with affirming-other manipulation.

Conclusion

These findings suggest that self-esteem predicts self-serving bias through depression and self-affirmation could trigger an increase of self-esteem, further decrease depression and improve self-serving bias for the individuals with IGD. The present article clearly identified the relationships among these factors and provided a new approach to promote positive self-concept in individuals with IGD. Future research is warranted to explore the lasting benefits of self-affirmation on domains of education, relationships and gaming withdrawal for the individuals with IGD among different populations.

Sex modulated the relationship between trait approach motivation and decision-making

It has been observed that one's Behavioral Approach System (BAS) can have an effect on decision-making under uncertainty, although the results have been mixed. To discern the underlying neural substrates, we hypothesize that sex may explain the conflicting results. To test this idea, a large sample of participants was studied using resting state fMRI, utilizing fractional Amplitude of Low Frequency Fluctuations (fALFF) and Resting-State Functional Connectivity (rsFC) techniques. The results of the Iowa Gambling Task (IGT) revealed an interaction between sex and BAS, particularly in the last 60 trials (decision-making under risk). Males with high BAS showed poorer performance than those with low BAS. fALFF analysis showed a significant interaction between BAS group and sex in the left superior occipital gyrus, as well as the functional connectivity between this region and the left ventrolateral prefrontal cortex. Additionally, this functional connectivity was further positively correlated with male performance in the IGT, particularly in the decision-making under risk stage. Furthermore, it was found that the functional connectivity between left ventrolateral prefrontal cortex and left superior occipital gyrus could mediate the relationship between BAS and decision-making in males, particularly in the decision-making under risk stage. These results suggest possible sex-based differences in decision-making, providing an explanation for the inconsistent results found in prior research. Since the research was carried out exclusively with Chinese university students, it is essential to conduct further studies to investigate whether the findings can be generalized.

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.