Cerebral responses to in-game failure and resting-state connectivity are associated with IGD-20 symptom severity

Internet Gaming Disorder (IGD) symptom severity may be associated with both context-dependent neural responses during gameplay and resting-state functional connectivity, but evidence integrating these measures remains limited. We conducted a secondary analysis of EEG data from 23 non-clinical young participants during naturalistic multiplayer online battle arena gameplay and eyes-open and eyes-closed rest. Event-related potentials (ERPs) and alpha- and beta-band power were quantified following slay and defeat events, while resting-state functional connectivity was assessed using the whole-brain mean weighted phase-lag index across five frequency bands. Age- and sex-adjusted partial correlations were evaluated with false-discovery-rate correction and bootstrap confidence intervals. After correction, lower defeat-related ERP amplitude was associated with greater relapse symptoms, whereas greater defeat-related beta-band power was associated with greater conflict symptoms. No slay-related association survived correction, and defeat-related alpha-band associations were nominal but did not remain significant after correction. During eyes-closed rest, delta-band connectivity was associated with mood modification, tolerance, relapse, and IGD-20 total scores, although the tolerance association was not supported by the Spearman sensitivity analysis. Exploratory, results-informed composites showed limited observed overlap, but their construction and evaluation within the same dataset precluded conclusions about complementary or independent neural domains. Given the small, non-clinical sample and cross-sectional design, these findings represent preliminary EEG correlates rather than causal mechanisms or validated biomarkers and require replication in larger independent cohorts.