Reduced Fast Periodic Visual Stimulation Oddball Responses to Threatening Faces Associated with Anxiety

Facial expression processing is crucial for social communication and survival, with anxiety disorders often linked to alterations in attentional biases toward threat-related stimuli. While previous studies using event-related potentials (ERPs) have yielded conflicting findings regarding threat sensitivity in anxiety, Fast Periodic Visual Stimulation (FPVS) offers a high signal-to-noise, implicit alternative for assessing emotion processing. This study utilized FPVS to investigate neural responses to facial expressions in individuals with anxiety compared to healthy controls. Forty-one adults participated, with 17 classified into the anxiety group based on self-reported diagnosis or PROMIS Anxiety scores. EEG responses were recorded while participants viewed sequences of neutral faces interspersed with emotional oddball expressions (angry, fearful, happy, and sad). Results revealed robust individual- and group-level neural responses, with significantly reduced summed baseline-corrected amplitudes (BCA) in central-parietal regions for angry and happy faces in the anxiety group. These findings suggest that anxious individuals exhibit attenuated discrimination of emotional expressions, particularly in higher-order processing regions, which may reflect cognitive avoidance of threat or general disengagement from emotional stimuli. The study highlights the potential of FPVS as a clinically relevant tool for objectively assessing emotion processing in anxiety and related disorders.