Self-Stimulation

a motor conditioned reflex by which an animal uses a lever to stimulate electrically the lower brain centers, including the rewarding center and the centers of stimulation and satisfaction. This phenomenon was discovered in rats by the American scientist J. Olds and the Canadian scientist P. Milner in 1954 and was subsequently reproduced in cats, dogs, dolphins, monkeys, and other animals. In many cases it was possible to show a connection between self-stimulation and the motivations of hunger, thirst, and sex, which made it possible to study self-stimulation as an artificial (imaginary) satiation. No such connection was observed in other cases, which indicated that the nerve apparatus of positive emotions in the hypothalamus and other parts of the brain was to a certain degree morphologically and physiologically independent. Human patients whose lower brain centers were stimulated for therapeutic and diagnostic purposes often reported feeling strong positive emotions and a sense of satisfaction and elation. This finally confirmed the relationship between self-stimulation and the lower brain centers of positive emotions.

Self-stimulation as a specific form of behavior has some characteristic features. When their satisfying brain centers are first stimulated by an electric current, animals start making searching movements, sniffing, and intensively exploring the environment. They quickly learn to receive self-stimulation by pressing the lever to close the electric circuit. Prolonged stimulation of the centers of satisfaction produces an emotionally negative response, and the animal will terminate stimulation by moving away from the lever. When the electric current is completely turned off, the self-stimulation conditioned reflex is usually quickly forgotten, and after several trials the animal ceases to press on the lever. Thus, self-stimulation does not become a habit, and the animal readily tolerates its cessation.

Changes in the electrical activity of the brain and the functions of the internal organs, for example, breathing, pulse rate, and blood pressure, during self-stimulation significantly differ from the aftereffects of the stimulation of the centers of the negative emotions of fear and pain. It is therefore possible to speak of the special state of the emotionally positive activation of the highest divisions of the central nervous system. Self-stimulation is a valuable experimental model with which to study the physiology of positive emotions and their effect on the activity of the brain and the body as a whole.

REFERENCES

Bekhtereva, N. P. Neirofiziologicheskie aspekty psikhicheskoi deiatel’nosti cheloveka. Leningrad, 1971.
Mikhailova, N. G. “Elektroentsefalograficheskie i vegetativnye korreliaty reaktsii samorazdrazheniia,” Zhurnal vysshei nervnoi deiatel’nosti, 1971, vol. 21, issue 1.
Milner, P. Fiziologicheskaia psikhologiia. Moscow, 1973. Pages 470–513. (Translated from English.)
Sem-Jacobsen, C. W. Depth-Electrographic Stimulation of the Human Brain and Behavior. Springfield, 111. [1968].

P. V. SIMONOV

self-stimulation

Self-Stimulation