A Twin Study of the Genetics of Fear Conditioning

Open Access
Publisher Website
Google Scholar
Abstract
FEAR CONDITIONING, a basic form of associative learning, is a traditional model for the acquisition of fears and phobias.1 Also, fear conditioning has long been an important experimental method for the study of etiologic processes related to fear and anxiety.2 Behavioral treatment paradigms for anxiety disorders, such as exposure and response prevention, are based on the related processes of habituation and extinction. Habituation allows individuals to ignore innocuous events by producing a progressive decline in response to repeated presentations of a neutral stimulus via nonassociative learning. Fear conditioning occurs when fear is associated with a neutral (conditioned) stimulus (CS) after pairing with a fear-provoking (unconditioned) stimulus (UCS), eg, electric shock. The CS acquires the fear-provoking response attributes of the UCS. Extinction is the decremental response to further presentations of the CS after its pairing with the UCS is eliminated. Interestingly, fear conditioning is more easily acquired and less readily extinguished with evolutionarily fear-relevant (snakes and spiders) than fear-irrelevant (circles and triangles) stimuli.3