The gray matter volume in superior frontal gyrus mediates the impact of reflection on emotion in Internet gaming addicts

Internet gaming disorder (IGD) is becoming a prevalent mental health concern around the world. However, the relationship among brain gray matter volume (GMV), emotion induced by decision-making and the level of reflection in IGD participants has not been fully elucidated to date. The current study aimed to explore this issue by combining a sequential decision task and voxel-based morphometry. Twenty-six IGD participants and 28 demographically matched healthy controls were recruited. After collecting Rumination-Reflection questionnaire data and high-resolution T1-weighted MRI data, participants were asked to complete a sequential decision task. The results demonstrated that compared to healthy controls, IGD participants exhibited significantly decreased GMV in the superior frontal gyrus (SFG). Moreover, GMV in the SFG of IGD participants fully mediated the impact of reflection level on the emotion of loss outcome during the sequential decision task. These results indicate that IGD is associated with reduced GMV in the SFG, and this structural change in IGD contributes to a particular relationship between the level of reflection and regret emotion for loss outcome in the sequential decision task.