My primary area of research focuses on the brain systems involved in the acquisition and inhibition of fear in humans. One of the most elegant processes humans and other animals possess to detect and react to signals of danger in the environment is classical conditioning, wherein stimuli associated with an aversive event acquire the capacity to elicit defensive behaviors. One of the primary goals of my research is to examine ways in which fear conditioning - - typically considered an evolutionarily conserved system shared across species - - interacts with other cognitive systems to determine how and what we fear in our environment.
One avenue of my research examines the ways humans utilize prior knowledge and inferential reasoning to generalize information about an aversive event to seemingly innocuous stimuli that are only indirectly related to the event. For example, an individual who survives an automobile accident may associate a number of stimuli or situations to the event that did not directly contribute to the accident, e.g. the song on the radio, the type of car involved, the time of day of the accident, or the neighborhood the accident occurred in. Later, these cues may act as strong reminders that evoke a sense of anxiety or fear. We use functional MRI to examine brain activity during fear learning and generalization, with a focus on the interaction between subcortical (e.g. the amygdala) and cortical (e.g. prefrontal and extrastriate visual cortex) regions.
Once acquired, it is often necessary for us to overcome (or extinguish) a fear that does not serve an adaptive function. For example, a fear of cars (and information associated with cars and driving) is maladaptive in most cases because we frequently encounter cars and many of us need to drive a car on a regular basis. Thus, another important goal of my research is to understand how it is that we overcome our fears, and to devise new experimental techniques to bolster this ability for individuals suffering from fear disorders. We focus on brain regions known from rodent models to be important for fear extinction, e.g. the ventromedial PFC, amygdala, and hippocampus.