Social Anxiety Modulates Default Mode Network Dysfunction and Working Memory Impairment During Social Media-Like Cue Distraction

Recent studies have highlighted the adverse impact of social-media distractions on cognitive abilities, especially among individuals with anxiety who experience heightened apprehensions about providing immediate online social responses. Nevertheless, the investigation into the mechanism is scarce. In this fMRI study, 94 healthy adults completed a 2-back working memory (WM) task under three conditions using a between-subject design: social media-like cue distraction (e.g., WeChat), nonsocial digital distraction (e.g., browser), and no distraction. Data were analyzed using task-evoked activation analysis based on the general linear model (GLM) and functional network connectivity (FNC) analysis based on independent component analysis (ICA). Results showed that social media-like cue distraction impaired WM and altered posterior cingulate cortex (PCC) activity. Crucially, under the social media-like cue distraction condition, the brain-behavior relationship in the PCC was significantly moderated by trait social anxiety: higher social anxiety predicted a positive coupling between PCC activation and task accuracy, with decreased PCC activation associated with decreased accuracy; conversely, individuals with low social anxiety exhibited decreased PCC activation together with increased accuracy. This study is the first to demonstrate that cues resembling social media can specifically disrupt core brain regions of the default mode network (DMN; PCC) functions during WM tasks and that this neural response is influenced by individual levels of social anxiety.