Fear Conditioning

Pavlovian fear conditioning is a behavioral paradigm in which an organism learns to predict an aversive event: an aversive stimulus, such as an electric shock, is repeatedly paired with a previously neutral context or stimulus, such as a room or a tone, until the once-neutral stimulus alone comes to elicit a state of fear. The phenomenon has been demonstrated across a very wide range of species, from snails to humans, and researchers measure it in different ways depending on the species, including verbal report and skin-conductance changes in humans and freezing behavior or a heightened startle reflex in other animals. A number of researchers have argued that the mechanisms of fear conditioning overlap substantially with the mechanisms of clinical anxiety disorders, and studies in rodents have traced how a fear memory is initially processed through the amygdala and hippocampus before becoming, over about four weeks, more permanently stored in the anterior cingulate cortex.