The rise in Internet gaming has led to significant challenges, including Internet Gaming Disorder (IGD), now recognized in the DSM-5 and ICD-11. IGD is characterized by excessive gaming leading to psychosocial problems. Incentive-sensitization theory posits that repeated rewarding experiences strengthen the incentive salience of addiction-related cues, resulting in craving. Attentional bias, measured by enhanced late positive potential (LPP) in EEG, reflects this increased salience. Increased LPP amplitudes to drug-related cues have been observed in various substance-use disorders. While increased LPP has been reported in IGD, research directly investigating the relationship between LPP amplitude, its source, and decision-making deficits in IGD is limited. Craving, an affective state linked to emotional evaluation of addiction-related information, can impact decision-making, favoring immediate gratification over long-term rewards. IGD is associated with compulsive gaming despite negative consequences, indicative of decision-making deficiencies. This study aimed to examine cue-related reactivity using ERP EEG, investigate the source of LPP, and explore the relationship between increased LPP and decision-making ability in IGD, hypothesizing increased LPP in visual attentional areas and decision-making deficits.

The introduction adequately reviews existing literature on IGD, incentive motivation, incentive-sensitization theory, craving, attentional bias, and the LPP component of event-related potentials (ERPs). It highlights the use of LPP as a marker of cue reactivity in substance use disorders and its potential application to IGD. The existing literature supports the hypothesis that IGD involves an attentional bias towards game-related cues, leading to craving and impaired decision-making. However, the study notes that previous research directly linking LPP amplitude, its neural sources, and decision-making in IGD is limited, providing justification for the current investigation.

This study employed a between-subjects design comparing 40 individuals diagnosed with IGD (meeting DSM-5 criteria) to 39 healthy controls (HC). Participants underwent clinical assessments including the Young's Internet Addiction Test (Y-IAT), Beck Depression Inventory (BDI-II), and Beck Anxiety Inventory (BAI). Intelligence quotient (IQ) was measured. Exclusion criteria included substance abuse, neurological disorders, and other significant medical conditions. The core methodology involved a cue-reactivity task, where participants viewed game-related and neutral pictures (from IAPS) while EEG data were recorded using a 64-channel Neuroscan system. Eye-movement artifacts were corrected. LPP was analyzed as mean amplitude between 400-700ms at centro-parietal and parietal electrode sites. Source localization of LPP was performed using standardized low-resolution brain electromagnetic tomography (sLORETA). Decision-making ability was assessed using the Cambridge Gambling Task (CGT), specifically focusing on Quality of Decision-Making (QDM). Statistical analyses included ANOVA, t-tests, ANCOVA, and partial correlation analyses, controlling for IQ, BDI, and BAI.

The IGD group exhibited significantly lower education levels and IQ scores compared to the HC group, and significantly higher scores on the Y-IAT, BDI, and BAI. The IGD group also showed significantly lower QDM scores on the CGT, indicating decision-making deficits. While not statistically significant, the IGD group showed a trend towards higher valence and craving ratings for game-related stimuli. Crucially, the IGD group showed significantly higher LPP amplitudes in response to game-related cues compared to the HC group, specifically at CP3, CP1, and P3 electrode sites. sLORETA analysis revealed hyperactivation in the superior and middle temporal gyri (associated with social perception) and hypoactivation in the frontal, limbic, and other cortical regions in the IGD group compared to the HC group when viewing game-related stimuli. A significant negative correlation was found between LPP amplitude and QDM in the HC group but not in the IGD group.

The increased LPP amplitudes in the IGD group, consistent with previous research, confirm the presence of attentional bias towards game-related cues. The hyperactivation in superior and middle temporal gyri suggests that individuals with IGD may perceive game-related cues as social stimuli. The lack of correlation between LPP and QDM in the IGD group indicates a disruption in the normal relationship between attentional bias and decision-making; the higher LPP does not appear to impact decision-making negatively in IGD as it did in controls. The findings suggest that objective measures like LPP, rather than subjective ratings, are more effective for identifying craving in IGD. The results support the use of LPP as a neurophysiological marker for IGD.

This study demonstrates increased LPP amplitudes and altered brain activation patterns in response to game-related cues in individuals with IGD. The findings highlight the potential of LPP as a neurophysiological marker for IGD diagnosis and for understanding the relationship between attentional bias, emotional arousal, and decision-making deficits. Further research could explore the longitudinal effects of IGD treatment on LPP amplitudes and related brain activity.

The study's limitations include a cross-sectional design which prevents causal inferences, a relatively small sample size, and the use of a specific set of games in the cue-reactivity task, limiting generalizability. The reliance on self-reported measures for some assessments (e.g. craving and valence) introduces potential bias. Further research with larger samples and diverse gaming contexts is needed.