Abstract
BACKGROUND: Individuals with social anxiety (SA) tend to show heightened attentional biases toward socially threatening information. However, it remains unclear at which stages of neural processing these biases emerge. This study aimed to clarify how social anxiety modulates the temporal dynamics of processing social threat words. METHODS: Electroencephalogram (EEG) signals were recorded while participants performed an emotional Stroop task, in which neutral and social threat words were presented in sequential blocks (neutral followed by threat). Participants were divided into high-social-anxiety (HSA) and low-social-anxiety (LSA) groups based on Liebowitz Social Anxiety Scale (LSAS) scores. Reaction times (RTs) and event-related potentials (ERPs)-specifically P2, early posterior negativity (EPN), and late positive potential (LPP)-were analyzed. RESULTS: Behaviorally, the HSA group exhibited significantly slower responses to threat words compared to neutral words, whereas no emotional effect was observed in the LSA group. ERP analyses showed that threat words elicited enhanced P2 amplitudes across both groups, suggesting increased early attentional orienting toward emotionally salient stimuli. Critically, the HSA group showed more negative EPN amplitudes to threat words, indicating intensified early-stage attentional allocation and perceptual encoding of emotional content. No significant effects of emotion or group differences were observed for the LPP component. CONCLUSIONS: These findings suggest that social anxiety modulates early-stage processing of social threat. While P2 reflects generalized early attentional sensitivity to threat, EPN is more selectively heightened in socially anxious individuals, capturing both attentional and perceptual enhancements in emotional processing. Attentional biases in social anxiety may thus emerge primarily during early perceptual encoding rather than sustained evaluative stages.