Dynamics of defensive behavior and memory in the face of stress and approaching social threat: A multi-method approach

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The defense cascade model is a transdiagnostic approach to study adaptive and maladaptive defensive behaviors (Fanselow, 1994; Lang et al., 1997). Originally derived from animal and recently also supported in human studies it has been shown that defensive behaviors systematically change with increasing proximity of a threat, depending on available response options such as escape. This change in defensive behaviors has been conceptualized in three defensive stages: pre-encounter defense (preemptive behavior, including unspecific vigilance when threat is likely but not detected), post-encounter defense (attentive freezing and threat-specific attention, when threat is detected) and circa strike (when threat is most imminent and requires escape behavior, flight-flight response). The central aim of the planned project is to extend this cascade of defensive responses, for the first time, to social threats in healthy individuals (proof of concept) and to investigate the communalities but also specifics of defensive response mobilization in individuals with symptoms of social anxiety. To identify different dynamic changes of defensive reactivity we will implement a novel social threat scenario (dynamically changing faces from neutral to angry expressions) with verbal devaluation (circa-strike) under different response options (uncontrollable threat vs. avoidance) using multiple peripheral physiological (startle reflex, heart rate, skin conductance) and brain measures (event-related potentials, ERPs; steady-state visual evoked potentials, ssVEPs). Moreover, because previous studies indicate that stress mediates freezing, avoidance behavior and memory, the project will also study the modulatory role of social stress on defensive behaviors, available response options and memory formation, all of which may be critical factors in the development and maintenance of social anxiety symptoms. The outcome of this project will not only give new insights into the adaptive dynamics of defensive behavior in response to approaching social threat but also give important implications for understanding defensive behaviors in social anxiety, which may also lead to better personalized treatment protocols (e.g., in order to reduce freezing and avoidance behavior).