An opponent-process theory of motivation: I. Temporal dynamics of affect.

A new theory of motivation is described along with its applications to addiction and aversion. The theory assumes that many hedonic, affective, or emotional states are automatically opposed by central nervous system mechanisms which reduce the intensity of hedonic feelings, both pleasant and aversive. The opponent processes for most hedonic states are strength-ened by use and are weakened by disuse. These simple assumptions lead to deductions of many known facts about acquired motivation. In addition, the theory suggests several new lines of research on motivation. It argues that the establishment of some types of acquired motivation does not de-pend on conditioning and is nonassociative in nature. The relationships between conditioning processes and postulated opponent processes are dis-cussed. Finally, it is argued that the data on several types of acquired motivation, arising from either pleasurable or aversive stimulation, can be fruitfully reorganized and understood within the framework provided by the opponent-process model. First, we describe the kind of phenome-non which has caught our attention. Two fictitious examples will suffice. In the first, a woman at work discovers a lump in her breast and immediately is terrified. She sits still, intermittently weeping, or she paces the floor. After a few hours, she slowly regains her composure, stops cry-ing, and begins to work. At this point, she is still tense and disturbed, but no longer terrified and distracted. She manifests the symptoms usually associated with intense anxiety. While in this state she calls her doctor for an appointment. A few hours later she is in his office, still tense, still frightened: She is obviously a very unhappy woman. The doctor makes his examination.