Excessive smartphone use is a phenomenon related to maladaptive smartphone use, leading to negative consequences. This study set out with the aim of assessing the effects of excessive smartphone use on behavioral and neural responses during facial emotional processing. We examined 25 excessive smartphone users and 27 normal control users using functional MRI during facial emotion processing and investigated Behavioral Inhibition System/Behavioral Activation System (BIS/BAS). The excessive smartphone use group (SP) showed neural deactivation in the dorsolateral prefrontal cortex (DLPFC) and dorsal anterior cingulate cortex (dACC) during the presentation of an angry face and emotional transition compared to that of the normal control group (NC). Additionally, the SP revealed neural deactivation of the superior temporal sulcus and temporo-parietal junction related to social interaction during emotional transition compared to the NC. We found that BAS-Reward Responsiveness level was correlated with behavioral responses during repeated happy faces related to emotional reward in SP compared to NC. It can thus be suggested that excessive smartphone use is likely to fail on cognitive control during emotional processing, and this impairment might be influenced on emotional processing related to social interaction.

Adaptive gaming use has positive effects, whereas depression has been reported to be prevalent in Internet gaming disorder (IGD). However, the neural correlates underlying the association between depression and Internet gaming remain unclear. Moreover, the neuroanatomical profile of the striatum in IGD is relatively less clear despite its important role in addiction. We found lower gray matter (GM) density in the left dorsolateral prefrontal cortex (DLPFC) in the IGD group than in the Internet gaming control (IGC) group and non-gaming control (NGC) group, and the GM density was associated with lifetime usage of Internet gaming, depressed mood, craving, and impulsivity in the gaming users. Striatal volumetric analysis detected a significant reduction in the right nucleus accumbens (NAcc) in the IGD group and its association with lifetime usage of gaming and depression. These findings suggest that alterations in the brain structures involved in the reward system are associated with IGD-related behavioral characteristics. Furthermore, the DLPFC, involved in cognitive control, was observed to serve as a mediator in the association between prolonged gaming and depressed mood. This finding may provide insight into an intervention strategy for treating IGD with comorbid depression.