Signs of Problematic Internet use Affect Resting-State EEG Microstates.

Easy access, overuse, and misuse of the internet have contributed to the rise of Problematic Internet Use (PIU). Despite a growing body of research linking excessive and addictive digital media use to adverse physical, psychological, social, and neurological consequences, identifying robust and widely accepted neurophysiological markers of PIU severity remains a significant challenge and a leading focus within the field. In this study, 156 healthy regular internet users (70 males; aged 18-35) were assessed using the PIUQ-9 questionnaire, along with measures of anxiety, depression, and obsessive-compulsive symptoms. Resting-state electroencephalogram (EEG) was recorded, and microstates (MS) of EEG were assessed. Psychological and neurophysiological profiles were examined both within the full sample and through comparisons between High and Low PIU groups. The microstate analysis resulted in extraction of 7 MS classes. A significant association between increased occurrence rate and time coverage of MS E - associated with interoception, salience and emotional processing, and PIU scores, both in the full sample and in High vs. Low group comparisons. Furthermore, parameters of MS B, MS C, and MS D showed significant negative associations with anxiety and obsessive-compulsive symptoms. These findings suggest that altered MS E dynamics, may represent a potential early functional biomarker of PIU, reflecting neural changes specifically associated with problematic internet behavior, rather than with psychological traits reflecting general psychopathology, particularly anxiety symptoms.