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 elevated anxiety-related characteristics (e.g., prior diagnosis or elevated symptom scores) and those without. EEG responses were recorded while participants viewed sequences of neutral faces interspersed with emotional oddball expressions (angry, fearful, happy, and sad). Results revealed robust neural discrimination responses to all facial expressions. Participants with anxiety-related characteristics showed significantly greater summed baseline-corrected amplitudes (BCA) at occipital electrodes in response to angry and sad oddball faces compared to the low-anxiety group. This was accompanied by reduced top-down interactions. Although, dimensional anxiety scores were generally low, suggesting results may reflect residual or trait-level differences rather than acute symptomatology, these findings provide preliminary evidence that FPVS may be sensitive to enduring differences in emotion processing associated with anxiety vulnerability.