MRI Study On Association Between Internet Addiction Tendency And Brain Structures In Adolescent Online Game Players

Objective:With the development and the popularization of the Internet,an increasing number of adolescents surf the internet and play online game excessively,which damages their physical and mental health and leads to adverse effect on family and society.Previous studies have demonstrated altered gray matter volume(GMV)in individuals with Internet gaming disorder(IGD),but the relationship between the GMV across whole brain and the tendency to IGD is not yet clear in adolescents.In the present study,we aimed to demonstrate the correlation between the tendency to IGD and the GMV in young online game players.Methods:In the present study,magnetic resonance imaging(MRI)with high resolution was performed on 67 male adolescents who played online game and the voxel-based morphometry(VBM)was used to calculate the GMV.The Young's Internet addiction test(IAT)was conducted to test the tendency to IGD.The FMRIB Software Library(FSL)was used to calculate the voxel-based correlations between the GMV and the IAT score after controlling for the age and years of education.We calculated the final result using the threshold-free cluster enhancement(TFCE)analysis,and the statistical threshold for significance was defined at P < 0.01.Additionally,we further studied whether the correlations between the GMV and the IAT score change when we added the total time of playing online game as covariate.The subjects were divided into two subgroups,namely,the high IAT score group(IAT score > 50)and the low IAT score group(IAT score ? 50).We compared the GMVs of the brain regions which were correlated with the IAT score.Result:(1)Clinical and behavioral resultThe IAT score of all the subjects ranged from 22 to 92.Subjects spent average 5.5 ± 4.7 hours/day on playing online games and lasted for average 56 ± 32 months from the beginning of playing online games to participating in our study.The total time of playing was calculated as hours per day multiplied by the days of playing online games.(2)Correlation between the GMV and the IAT score.The GMVs of the bilateral postcentral gyri(postCG)(L_PreCG /PostCG r =-0.541,P < 0.001;R_PostCG r =-0.395,P = 0.001),the bilateral precentral gyri(preCG)(L_PreCG r =-0.290,P = 0.019;R_PreCG/PostCG r =-0.290,P = 0.019),the right precuneus(r =-0.413,P = 0.001),the left posterior midcingulate cortex(pMCC)(r =-0.375,P = 0.002),the left inferior parietal lobe(IPL)(r =-0.314,P = 0.001)and the right middle frontal gyrus(MFG)(r =-0.389,P = 0.001)were negatively correlated with the IAT score.The correlation still existed between the IAT score and the GMVs of the bilateral postCG,the left preCG,the left pMCC,and the right MFG after controlling for the total time of playing online game.(3)The comparison of the GMV.When the participants were divided into the high IAT score group(IAT score > 50)and the low IAT score group(IAT score ? 50),the GMVs of these IAT-related brain regions were lower in high IAT score subgroup than in low IAT score subgroup(P < 0.05).Conclusion:The GMVs of brain regions involved in sensorimotor process and cognitive control are associated to the IGD tendency.These findings may lead to new targets for preventing and treating the IGD.