The past two decades have brought dramatic progress in the neuroscience of anxiety due, in no small part, to animal findings specifying the neurobiology of Pavlovian fear-conditioning. Fortuitously, this neurally mapped process of fear learning is widely expressed in humans, and has been centrally implicated in the etiology of clinical anxiety. A major thrust of research in the ANGST laboratory includes human fear-conditioning experiments that bring recent advances in animal neuroscience to bear on working, brain-based models of clinical anxiety. To this end, our lab applies a 3-stage research process:
First, behavioral and psychophysiological experiments are applied to identify specific fear-conditioning processes that operate aberrantly in the anxiety disorders.
Second, we apply functional and structural neuroimaging techniques in healthy controls to specify the network of brain areas subserving these clinically-relevant conditioning processes.
Third, anxiety patients are neuroimaged to identify brain loci within this network that may drive fear-conditioning abnormalities in clinical anxiety.
Through this work, we hope to contribute to the larger goal of future brain-based diagnostics and neurally targeted interventions for clinical anxiety.
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.
Individual differences in fear generalization, generalized avoidance, and Pavlovian to instrumental transfer of fear.
Enhanced levels of generalization of the fear response to perceptually similar stimuli (i.e., fear generalization) has been demonstrated to lead to a generalized avoidance response. However, there are many sub-components of both the fear and avoidance process that are differentially influenced by personality substrates. For example, decision making (a core process underlying avoidance of feared stimuli) can be impaired by superordinate personality factors, such as high degree of neuroticism, or more subordinate factors, such as impulsiveness or callousness. The current study seeks to map the personality and cognitive functioning associated with generalized fear and avoidance, and to take preliminary steps towards predicting fear learning and response based on these factors. In this study we aim to: 1) identify personality and cognitive functioning correlates associated with fear and avoidance generalization; 2) use these correlates to potentially predict fear and avoidance generalization; and 3) apply advanced quantitative techniques (e.g., estimated structural equation modeling) to investigate latent factors of the studied processes.
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.