Compensatory increase of functional connectivity density in adolescents with internet gaming disorder

Behavioral studies have demonstrated visual attention bias and working memory deficits in individuals with internet gaming disorder (IGD). Neuroimaging studies demonstrated that individuals with IGD presented abnormalities in brain structures and functions including resting-state functional connectivity (rsFC) disturbance. However, most previous studies investigated IGD-related rsFC alterations by using hypothesis-driven methods with priori selection of a region of interest, which cannot provide a full picture of the rsFC changes in IGD individuals. In this study, we recruited 27 male IGD adolescents and 35 demographically matched healthy controls (HCs) to investigate abnormal connective property of each voxel within whole brain of IGD adolescents using resting-state functional connectivity density (rsFCD) method, and further to evaluate the relationship between altered rsFCD and behavioral performances of visual attention and working memory. The results exhibited no significant intergroup difference in behavioral performance (visual working memory and attention). The IGD adolescents exhibited higher global/long-range rsFCD in the bilateral dorsal lateral prefrontal cortex (DLPFC) and the right inferior temporal cortex (ITC)/fusiform compared with the HCs. Although no significant correlation survived after Bonferroni correction, higher global/long-range rsFCD of the bilateral DLPFC was correlated with the Young's internet addiction test (IAT) score and/or behavioral performance in IGD adolescents using an uncorrected threshold of P < 0.05. In conclusion, IGD adolescents demonstrated increased rsFCD in the brain regions involved in working memory, spatial orientation and attention processing, which indicated that increased rsFCD may reflect a compensatory mechanism for maintaining the normal behavioral performance in IGD adolescents compared with the HCs.