Threat-Avoidance Learning in Anxiety Patients

Overview

Anxiety disorders are characterized by exaggerated levels of fear that are not proportional to the actual level of threat. More specifically, anxiety patients have marked deficits in the downregulation of fear reactions during situations of objective safety. Pre-clinical research on Pavlovian fear conditioning and extinction has discovered that fear downregulation stems from areas in the prefrontal cortex (the ventro-medial prefrontal cortex, vmPFC) that recruit intercalated cells in the amygdala to inhibit its central nucleus, which is responsible for a variety of behavioral expressions of fear (Milad \& Quirk, 2012). Accordingly, functional magnetic resonance imaging studies (fMRI) revealed reduced vmPFC activity coupled with increased fear reactions during situations of objective safety in anxiety patients (Milad et al., 2009). Another core symptom of anxiety disorders, though much less investigated, is the excessive avoidance of situations that trigger the fears. These 'safety behaviors' often interfere with daily life activities and valued goals in life, and they are thought to perpetuate the exaggerated levels of fear by precluding opportunities to learn that the feared situations are actually not dangerous. Surprisingly, experimental research on avoidance behaviors in anxiety patients is virtually non-existent. This experiment modifies the Pavlovian fear conditioning procedure to include avoidance, and explores the behavioral and neural processes of this type of fear regulation in anxiety patients (trans-diagnostically) and healthy individuals.

Conditions