Experimental psychogenic hypertension: Blood pressure changes conditioned to painful stimuli (Schizokinesis)

Summary

• 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 ofschizokinesis.

• 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.