Regulation of Craving in Internet Gamers

As with the experiment about tDCS effects on regulation of craving and aversive emotions, the experiment aims to test whether tDCS over dlPFC will enhance cognitive regulation of craving and aversive emotions. It is a within-subject, sham-controlled, double-blind design. Each participant receive both active and sham tDCS of dlPFC in a randomized order separated by one week. During both active and sham tDCS sessions, participants will perform regulation of craving (ROC) and emotion regulation (ER) tasks. In the ROC task, participants will be asked to downregulate and upregulate craving elicited by gaming pictures using cognitive reappraisal. In the ER task, participants will be asked to downregulate and upregulate aversive feelings elicited by negative pictures using cognitive reappraisal. During these tasks, self-report ratings and skin conductance responses (SCRs) will be recorded. The cognitive regulation ability is indexed by rating and SCRs differences between the up- and downregulation conditions. As with the experiment about tDCS effects on attentional bias, the experiment aims to test whether tDCS over dlPFC will enhance inhibitory control of attentional bias towards gaming related cues. The inhibitory control of attentional bias will be measured by a cognitive task in which participants will perform a number classification task with gaming pictures and non-gaming pictures being distractors. The experiment is a within-subject, sham-controlled, double-blind design. Each participant will receive both active and sham tDCS of dlPFC in a randomized order separated by one week. After each tDCS session, participants will complete the cognitive task assessing inhibitory control of attentional bias. During the task, reaction times (RTs) wil be recorded. The attentional bias is indexed by RTs differences between trials with gaming pictures and trials with non-gaming pictures.