The effect of visual working memory load on attentional bias in social anxiety

Social anxiety is closely associated with abnormal attentional bias toward threatening stimuli. Although working memory plays an important role in the relationship between anxiety and attentional bias, few studies have determined whether and how visual working memory load affect attentional bias in socially anxious individuals. More importantly, the neurophysiological mechanisms of these effects remain unclear and need to be detected. Via event-related potential (ERP) by using a task that combines dot-probe and color lumps' memory, this study investigated the time course of attentional bias in socially anxious individuals and the effects of visual working memory load. ERP results show that in the high social anxiety group, disgusted faces did not elicit a larger N1 (vs. neutral faces) at baseline, but induced a larger P2. Additionally, compared to the low social anxiety group, disgusted faces elicited a larger P2 in the high social anxiety group. Regarding low working memory load, in the high social anxiety group, disgusted faces elicited a larger N1 and N2pc (vs. neutral faces) and a smaller P2 (vs. baseline). Our findings suggest that the attention of socially anxious individuals does not immediately shift towards threatening stimuli at the beginning but rather leads to more intensive processing of threatening stimuli afterwards. Although the attentional processing of threatening stimuli in socially anxious individuals is attenuated by visual working memory loads, low visual working memory loads activate and accelerate attentional orientation to threatening stimuli. Our findings extend previous work to the executive function field, and provide neurophysiological evidence for the findings on attentional bias modification training.