Pleasure Centers in the Brain

Psychology has gone through a period of fantastic growth during the last 30 years, primarily because it seemed to offer college students some explanation of their malaise and some understanding of themselves which would free them from anxiety. Then why, if we are interested in the weal of these college students, do we expend our research on albino rats? Facetious though it may appear, there must be some truth in the answer that the albino rat is an excellent model of the contemporary American college student, or at least the majority of them. Neither the student, having been bred in America, nor the white rate, having been bred in a laboratory, has ever experienced a need in its life. The question of what might drive behavior in the absence of needs would have bothered theoretical psychologists and Puritan preachers alike at the time I entered the field in the late 1940's. The concept of needdriven behavior is simple, compelling, and in complete accord with the simplest concept of evolution. It says that damage to the organism, or deprivation inimical to health, causes physiological processes which are experienced as discomfort, and that behavior proceeds in a random or a guided fashion until discomfort is alleviated. An uncomfortable person is in need, and need justifies a multitude of sins. A few short steps ahead of this conception-and representing no significant advance in sophistication-is the drive-reduction theory of learning. The conception of this theory is that somewhere in the brain incoming sensory messages cross outgoing motor messages. If a sudden drive reduction occurs, a connection becomes fixed more or less permanently, so that the next time the sensory message will cause the rewarded behavior. It is possible to attack this theory on a variety of grounds, one of which is the simplicity of its attitude toward the data processing that goes on inside the brain. This theory gives rise to a law that states, "Learning occurs only when discomfort is relieved." For an organism that seeks novelty, ideas, excitement, and good-tasting foods, the drive-reduction theory was a Procrustean bed. Whatever did not fit was shorn from our image of the man and the rat. Drugs, good foods, and sex were thought of in terms of a need-that is, a hurt generated by withdrawal. Even the coddled white rat was trapped into his forward motion by his residual pains. Behavior was a downhill course toward quiescence, and its energetics were a series of accidents from outside which countered the downhill trend. If behavior was not aimed to repair these damages and concurrent discomforts, then why was it selected and why did it survive? This rhetorical question was given in answer to all counterarguments. It is interesting that research on the albino rat, if it has not gone far to improve the sophistication of the