Exploring the Defense Cascade Model in the Context of Social Anxiety: A Pilot Psychophysiological Study

The present study investigates how individuals with subclinical social anxiety (n=15) respond to perceived social threat on a psychophysiological level through steady-state visual potentials (ssVEPs), electrodermal activity (EDA), and heart rate (HR) in a paradigm resembling the defense cascade and threat imminence models. Twenty-seven participants completed the task involving flickering faces (angry or neutral) paired with two types of loud statements, which could be avoided or not (active avoidance and passive avoidance conditions). Contrary to the hypotheses, a significant difference between groups was found only for skin conductance response, and ssVEPs were generally higher for the neutral facial expressions compared to the angry ones. Heart rate decelerated coherently with the defense cascade model, suggesting freezing behavior and information intake. Oppositely, skin conductance decreased, resulting to be more pronounced response for neutral threat in low socially anxious participants showing better habituation compared to high socially anxious subjects. In addition, a specific effect of avoidance was found only for skin conductance, and therefore, findings only partially support the defense cascade model. However, the small and unbalanced sample size might have affected the results, calling for further research on the application of the model, especially in the context of social anxiety.