1. During habituation in 4 dogs to a new environment and attachment of apparatus, the blood pressure was at first high but fell from about 175 systolic the first day to about 135 on the ninth day. 2. In the first group of dogs used two years previously to form 3 cardiac conditional reflexes to 3 intensities of shock, the blood pressure measured after a 13-month rest was retained and specific to the 3 intensities of shock. In another group of 2 dogs the blood pressure was specific to the excitatory and to the inhibitory signals for pain. 3. The conditioned hypertension was parallel to the conditioned heart rate. 4. The conditioned hypertension was parallel to the motor conditional reflex with certain exceptions: the conditioned hypertension was, like the cardiac conditional reflex, quicker to form and more persistent, thus being present often in the absence of the motor conditional reflex--an evidence of schizokinesis. 5. The conditioned hypertension was retained for a 13-month rest period without intervening training, being present immediately when the dog was brought back into the environment where the stress had been given. 6. Although the conditioned hypertension was retained in the long rest period, it could in one dog be reduced somewhat by repeating the conditional stimulus without the shock (non-reinforcement), a more efficient way of extinction than simple rest. In another dog the hypertension became exaggerated though there was no repetition of the stress, showing evidence of an internal development (autokinesis). 7. The amplitude of the conditioned hypertension varied according to the individual dog from about 130 average control to limits of 150 to 225 (conditioned hypertension) in the separate dogs.

The role of the experimenter in the behavioral study, although recognized by Darwin, Pavlov, psychiatrists and others, has not been adequately evaluated in terms of the quantitative measures of the CR. Our study in this paper concerns especially the cardiac changes induced by “Person” in normal and pathological animals—monkey, dog, cat, opossum, guinea pig and rabbit. Owing to the greater sensitivity of the cardiovascular and respiratory systems, these are more reliable and delicate measures than the usual somatic muscular ones. The Person can be used as an unconditional stimulus on the basis of which conditional reflexes are formed. Person has an especially pronounced effect on neurotic animals—shown often in a more pronounced way in the cardiorespiratory responses than in the more superficial behavioral ones. This Effect of Person may provide insights into the production of neurosis as well as some of the beneficial effects of therapy, e.g., the personal factor of the therapist.

People have marked effects on dog's heart rate, with great individual variations for different persons. Apparently people to which the dog is attached have the greatest effect upon heart rate. Replications of the animal experiments using the psychotherapist and two other people revealed no effects upon the heart rate of a schizophrenic human. In the human the effects of people are probably best demonstrated in connection with verbal communication.