ABSTRACT

Classical conditioning, described by Pavlov, has emerged as an important tool in our efforts to understand the mechanisms of emotional learning. Using a classical fear conditioning paradigm, research with nonhuman animals has identified the amygdala as a critical structure for emotional learning. This chapter reviews how studies in humans have extended the role of the amygdala to social means of emotional learning and culturally acquired race bias. Although cultural knowledge and some forms of social communication may be uniquely human characteristics, how emotional value is expressed in these domains seems to rely on basic mechanisms that are shared across species.

OVERVIEW

The basic principles of classical conditioning were identified by Ivan Pavlov more than a century ago when he showed that dogs would salivate to the ringing of a bell that had previously been paired with the delivery of food. More recently, investigators have used classical conditioning paradigms to help understand the neural mechanisms of emotional learning. These studies have focused on classical fear conditioning. In a typical fear conditioning paradigm, a neutral stimulus, called the conditioned stimulus (CS), is paired with an aversive event, the unconditioned stimulus (UCS). After a few pairings, the animal learns that CS predicts the UCS, and this previously neutral stimulus begins to elicit a fear response, called the conditioned response (CR). Using this paradigm, scientists studying nonhuman animals have been able to map the neural pathways of emotional learning from stimulus input to response output (see LeDoux, 2002, for a review).