After implantation of electrodes at various points in the brains of rats, the animals were placed in a Skinner box, arranged in such a manner that they could stimulate themselves by pressing the lever. The results indicate that various places exist in the brain “where electrical stimulation is rewarding in the sense that the experimental animal will stimulate itself in these places frequently and regularly for long periods of time if permitted to do so.” The reward phenomenon appears most reliably when the electrodes are placed in the septal region, where an extreme degree of control was observed.