ABSTRACT
For the better part of the last century, the study of learning has held a special intellectual appeal for psychologists and biologists alike. This attraction has arisen not only from the realization that the processes underlying learning are eminently approachable experimentally, but from an appreciation for the rich conceptual importance that learning holds for the understanding of both brain and behavior. One of the most intriguing features of learning is its remarkable specificity. Animals must not simply change their behavior, they must change it in specific ways to meet particular environmental demands. Under one set of conditions, it may be important to increase a behavior, while another set of circumstances might require that the behavior be suppressed. Similarly, animals must learn to pay attention to some stimuli, but ignore others. Associative forms of learning, such as classical conditioning and operant conditioning, further require that the animal associate one stimulus with another, or a stimulus with a response.
