Naturalistic fNIRS assessment reveals decline in executive function and altered prefrontal activation following social media use in college students

Abstract As of 2023, 69% of adults and 81% of teens in the U.S. use social media regularly. This study investigates the immediate impact of social media consumption on executive functioning (EF) and emotion in college students using a wearable, naturalistic functional near-infrared spectroscopy (fNIRS) system. Twenty participants completed EF tasks and self-report questionnaires both before and after a brief social media exposure. Over half (55%) met criteria for social media addiction, with an average Instagram usage of five hours per week. Behaviorally, social media exposure led to reduced accuracy in EF tasks, including n-back and Go/No-Go paradigms. Neurally, increased medial prefrontal cortex (mPFC) activation suggested greater cognitive effort and performance monitoring, while decreased dorsolateral (dlPFC) and ventrolateral prefrontal cortex (vlPFC) activation reflected impairments in working memory and inhibition. Reduced inferior frontal gyrus (IFG) activity was also linked to difficulties suppressing motor responses. Emotional changes were modest, with the control group reporting slightly lower happiness post-intervention. These findings demonstrate the cognitive cost of social media use and underscore the potential of wearable fNIRS for real-world brain monitoring. This approach may inform future interventions and support precision mental health strategies targeting digital behavior.