Pavlovian Conditioning and Extinction Methods for Studying the Neurobiology of Fear Learning in PTSD

We describe a human threat conditioning and extinction paradigm used to study posttraumatic stress disorder as well as other psychiatric disorders. This paradigm was designed based on rodent threat conditioning paradigms for its application in translational neuroscience research. It is a passive viewing emotional learning and memory task composed of four phases. The first is the threat conditioning phase, followed by a threat extinction learning phase. Subsequently, memory for extinction learning is evaluated in extinction recall after a time delay (typically 24 hours after extinction learning). The last phase is the renewal of threat responding after extinction. Participants undergo this paradigm while in an fMRI scanner to identify brain correlates during all emotional learning phases. The duration of each experimental phase is approximately 13 minutes. Various time delays can be inserted between phases, depending on the aims of the experiment. Other experimental measures such as skin conductance responses and subjective measures could also be acquired during all experimental phases.