ABSTRACT
In this chapter, the author details the relationships between neurophysiological and behavioral observations. From the very beginning I. P. Pavlov emphasized that the salivary conditioned response (CR) involves much more than the response of that single gland. The classic work of Pavlov showed that, while a CR is being learned, there is a phase of increasing stimulus generalization. Early in his work, Pavlov found that “In the hungry animal, food naturally brings about a powerful unconditioned reflex, and the conditioned reflex develops quickly. In addition to the degree of hunger, alimentary conditioned responses are dependent on another motivational variable, namely, the amount and quality of food used as the unconditioned stimulus. The author briefly summarizes the results of a series of studies on hunger elicited by direct electrical and chemical stimulation of the brain. He shows how the techniques of electrical and chemical stimulation are yielding basic information on drive and reward.
