APA Dictionary of Psychology

stimulation of a brain region by direct application of an electric current through implanted electrodes. When this stimulation is controlled by the individual being stimulated, it is called intracranial self-stimulation; it also may be called brain self-stimulation or electrical self-stimulation of the brain (ESSB). In nonhuman animal experiments, this is achieved by the animal performing an operant response, such as lever pressing. When the electrodes are placed in certain areas of the brain, animals will press the lever quite frequently, indicating that stimulation of these brain areas is rewarding. [originated in 1954 by U.S. psychologist James Olds and Canadian psychologist Peter M. Milner]