Fear generalization as a pathological mechanism of PTSD in OEF/OIF veterans.
One central, yet largely understudied, symptom of post-traumatic stress disorder (PTSD) is the tendency to display fear in reaction to benign or safe events that ‘resemble’ the traumatic event. This study represents the first effort to study the psychobiology of this type of fear overgeneralization in PTSD using both functional neuroimaging (fMRI) and psychophysiologic methadology. The significance of this study derives from the important gains to be made from linking abnormalities found in PTSD (e.g., stimulus overgeneralization) to specific psychobiological processes that may contribute to future brain based diagnostics and neutrally targeted interventions. Given the cross-species relevance of fear conditioning, experimental paradigms assessing generalization of conditioned fear represent a translational approach that bring to bear a wealth of neural data and theory from animal research to explanatory models of PTSD.
Attentional contributions to fear generalization
Anxiety disorders are one of the most common forms of mental disorders and result in substantial impairment and distress. One of the hallmarks of anxiety disorders is maladaptive fear learning. In particular, enhanced levels of generalization of the fear response to perceptually similar stimuli (i.e., fear generalization) is implicated as a core component of the anxiety disorders. However, the mechanisms that underlie fear generalization, and how they are specifically associated with anxiety pathology, are still unclear. The current study seeks to investigate a potential mechanism underlying fear generalization: attentional bias to threatening information. Our objectives are to apply psychophysiological and eye tracking methods to: 1) identify attentional and biological mechanisms associated with fear generalization and 2) test the degree to which such mechanisms operate in people with and without elevated anxiety levels, to better understand how the basic mechanisms as they operate in health might become maladaptive and contribute to disorder and dysfunction.