Conditioned Emotional Response

A conditioned emotional response, also called conditioned suppression or a conditioned fear response, is a learned emotional reaction produced through classical, Pavlovian conditioning, most often studied as the pairing of a relatively neutral stimulus with a painful or fear-inducing unconditioned stimulus. Once the pairing has been learned, the formerly neutral stimulus alone comes to elicit fear on its own. The commonly used illustration is a person or animal that is bitten by a dog: the sight of a dog, previously neutral, becomes a conditioned stimulus that elicits a fear response purely because it was paired with the pain of the bite, the unconditioned stimulus. The term refers both to this specific learned reaction and to the experimental procedure researchers use to produce and measure it in classical and Pavlovian conditioning research.