Prefrontal cortex activity of adolescents with problematic smartphone use in response to gains and losses: A functional near-infrared spectroscopy study.

Problematic smartphone use (PSU) has become a widespread problem that is highly prevalent in adolescent population. Previous studies suggest that PSU is associated with impairment in reward processing system. Thus, increased sensitivity to rewards could make individuals more vulnerable to abusive behaviors, such as PSU. However, little is known about its underlying neural mechanisms. This study aimed to investigate the neural correlates of reward and punishment processing in adolescents with PSU by evaluating the hemodynamic responses to monetary gains and losses using functional near-infrared spectroscopy. Seventy adolescents (aged 13-18 years) participated in the present study. They were categorized into two groups based on their level of PSU: 36 problematic smartphone users and 34 nonproblematic smartphone users, who were matched for age and sex. Changes in oxygenated hemoglobin levels in the prefrontal cortex were measured using a 22-channel functional near-infrared spectroscopy system during the performance of the Iowa Gambling Task. Additionally, participants completed a Sensitivity to Punishment and Sensitivity to Reward Questionnaire. Our results showed that problematic smartphone users exhibited heightened sensitivity to reward than nonproblematic smartphone users, but no significant differences in oxygenated hemoglobin level changes between both groups were found. These results suggest that increased sensitivity to reward could make smartphone users more vulnerable to abusive behaviors related to these devices. However, PSU does not follow the same brain patterns as other addictions in processing monetary rewards. (PsycInfo Database Record (c) 2026 APA, all rights reserved).