The foregoing remarks imply that the hypothalamic balance plays a crucial role at the crossroads between physiological and pathological forms of emotion. If this is the case, one would expect that not only the various procedures just mentioned which alter the hypothalamic balance would influence emotional state and behavior but that emotion itself would act likewise. We pointed out that emotional excitement may lead to psychosomatic disorders and neurotic symptoms, particularly in certain types of personality, but it is also known that the reliving of a strong emotion (``abreaction'') may cure a battle neurosis. This phenomenon raises the question whether the guidance of the emotions for therapeutic ends may not have an even wider application in the area of the neuroses. Being a strictly physiological procedure, one may expect from such a study additional information on the nature of the emotional process itself.

Wolpe's experiments and therapeutic work lie in this area. He showed convincingly that anxiety is a learned (conditioned) reaction and is the basis of experimental and clinical neuroses and assumed, therefore, that the neuronal changes which underlie the neuroses are functional and reversible. An important observation of Pavlov served as a guide post to achieve such a reversibility by physiological means. In a conditioning experiment, he demonstrated the antagonism between feeding and pain. A mild electrical shock served as a conditioned stimulus and was followed by feeding. The pain became thus the symbol for food and elicited salivary secretion (conditioned reflex). Even when the intensity of the shocks was increased gradually, it failed to evoke any signs of pain. Since strong nociceptive stimuli produce an experimental neurosis during which the animals fail to eat in the experimental situation, Wolpe thought that he could utilize the feeding pain antagonism to inhibit the neurotic symptoms through feeding. Appropriate experiments showed that this is, indeed, possible. He then applied this principle of reciprocal inhibition to human neuroses. He took advantage of the antagonism between aggressive assertiveness and anxiety and found a relatively rapid disappearance of anxiety when the former attitude was established.