From attentional bias to neural dysfunction: Multimodal evidence for emotion processing deficits in individuals with problematic social media use

Background and Aims: Problematic social media use (PMSMU) shows strong mental health associations, yet its neurocognitive mechanisms remain unclear. This study investigates emotion processing deficits in PMSMU, focusing on valence-specific attentional biases and neural dysfunction. Methods: 113 Chinese college students stratified into low-risk (n = 55) and high-risk PMSMU (n = 58) groups completed psychological assessments and an emotion recognition task using facial stimuli depicting the seven basic emotions selected from the Chinese Facial Affective Picture System (CFAPS) during simultaneous eye-tracking and fNIRS recording prefrontal-temporal activation. Results: High-risk PMSMU showed enhanced accuracy for joy emotion (82.58% vs. 74.31%, p = 0.013) but impaired negative emotion recognition (64.29% vs. 69.87%, p = 0.006). Eye-tracking revealed reduced nose-root fixation and increased mouth and the middle of nose attention. fNIRS identified negative-emotion-specific hyperactivation in right temporal (c1, p = 0.017) and left frontal lobes (c9, p = 0.021). Temporal activation correlated with slower sadness recognition (r = 0.345), while attention deficits linked to reduced fear accuracy (r = -0.261) and temporal hyperactivity (r = 0.377). High-risk subjects reported poorer psychosocial functioning (poorer interpersonal skills, attentional control, and higher levels of anxiety and depression, p < 0.001), with frontal activation moderating negative-emotion-impairment relationships. Conclusion: PMSMU is characterized by valence-specific disruptions-including attentional bias toward positive cues, impaired fear processing, and prefrontal-temporal hyperactivation during negative emotion decoding-that collectively define it as a neurobehavioral condition leading to psychosocial impairment.