Electrical Stimulation of Brain and Behavior: The Questions of Free Will

Delgado was able to demonstrate unequivocally that minute electrical currents administered through electrodes implanted in the brains of humans and animals produced highly specific emotional and behavioral responses, depending upon the specific part of the rain stimulated. Delgado was a superb showman, and in his most famous demonstration he stopped a charging bull in its tracks by using a radio signal sent from a hand-held transmitter to a receiver implanted in the bull’s head. The TV tape of this exhibition was shown around the world.

Delgado discovered the exact parts of the brain in which electrical stimulation produced fear, anxiety, pleasure, euphoria, or rage in human subjects. He found that certain sites produced major personality alterations. Fro example, stimulation of one such site could cause very proper, reserved young ladies to become flirtatious and sexually aggressive.

Other sites inhibited maternal or aggressive behavior. In short, Delgado was able to profoundly alter human behavior through electrical stimulation of discrete areas of the brain.

He promoted the use of this technique for producing desirable behavior in psychiatric patients. When he used the technique on patients who were not too emotionally ill to be unaware o what was happening, they reported that their behavior had been changed not because they had wanted it to, but because they had been unable to overcome the power of the electrical signal.

This work ultimately led to experiments in which electrodes were implanted in the pleasure centers of rats’ brains. The animals were provided with two levers to press. One of these delivered food, and the other produced electrical stimulation of the pleasure center. Invariably, the rats chose to press the lever that stimulated the pleasure center, even to the extent that they died of starvation. The experiments, which were widely reported, were viewed as being “demeaning” to the animals and, by implication, to human beings.

Delgado’s work was viewed with open hostility and outrage by the scientific community. These opinions were strengthened by the publication of his book Physical control of the Mind: Toward a Psychocivilized Society, in which he summarized his experiments and his conclusions.

To Delgado, the mind existed only in the brain; to postulate its existence as an independent entity was sheer nonsense. He rejected the cherished concept of free will, and he proposed that the mind was a functional entity produced by the electrical operations of the brain. As such it could--and should--be manipulated by external means:

"Because the brain controls the whole body and all mental activities, electrical stimulation of the brain could possibly become a master control of human behavior by means of man-made plans and instruments…To discuss whether human behavior can or should be controlled is naïve and misleading. We should discuss what controls are ethical, considering the efficiency and mechanisms o existing procedures and the desirable degree of these and other controls in the future."

Delgado was viewed as promoting human mind control, and his book evoked a storm of protest. Apparently, the mechanistic concept of life works as long as it is not extended into such areas as consciousness, mind, and free will.

In the early 1960s, I became aware of the work of Dr. H.J. Campbell of the Institute of Psychiatry at De Crespigny Park in London. Campbell was disturbed by Delgado’s demonstrations of the power inherent in the pleasure center of the brain, and particularly by its “terrible compulsiveness,” as revealed by the rat experiments. He viewed the use of electrodes and internal stimulation as unnatural, and he asked an important question: How do the pleasure areas become activated in normal life?

Through a long series of experiments, Campbell concluded that all new sensory input could stimulate the brain’s pleasure centers. His experiments involved providing animals with a away to turno n a stimulus, such as a light or, in the case of aquatic animals, a mild electrical current in the water. He found that initially the animals behaved as though the activity that turned on the stimulus was directly connected to the pleasure center. The aquatic animals, for example, would repeatedly swim through the stimulating apparatus. However, the activity did not continue for long. After the passage of time, it slowed and finally stopped. In other words, the animals because “satisfied” and no longer felt the need for such sensory input. This was quite different from direct electrode stimulation of the pleasure center.

Campbell postulated that as the nervous system evolved and became more complex, there was an accompanying need for the pleasure center to be kept activated by sensory stimuli. He went on to propose that the sensory inputs required for lower animals were simpler and less complex than those for humans. Finally, he suggested that evolution was still progressing, and that humans would slowly lose the need for sensory stimuli to activate the pleasure center. In its place, they would acquire the ability to activate the pleasure center themselves simply by “exercising the capacity for thought” and “using the sense organs as ancillaries to mental phenomena.” Campbell envisioned a utopian society that would be based solely on the pleasures of rational thinking, a view diametrically opposed to Delgado’s.

I was interested in Campbell’s work because of my own work on the salamander nervous system and its electrical activity. At the time, there was a growing interest in so-called electrosensing by aquatic animals, and some researchers were beginning to think that this was a mechanism by which animals found food in their watery environment. In that light, I wondered whether Campbell’s animals had simply been looking for something to eat--would a well-fed salamander swim back and forth through the stimulator?

It also struck me that the animals did not stay in the stimulating apparatus, but rather had to swim continuously back and forth through it to obtain “gratification.” The fact that the electrical stimulus used by Campbell was a direct current suggested to me that the actual stimulus was ELF pulses o electricity that resulted from the animal’s repeat passages through the apparatus. Unfortunately, my letters to Dr. Campbell were not answered and I could not locate any of his reports in the scientific literature. While I gave up on these questions, it seemed to me that his basic idea--that normal stimulation o the pleasure centers was via sensory input--was correct. After all , neither human beings nor any other organisms were equipped with electrodes imbedded in the limbic region of the brain. Nevertheless, Campbell’s experimental results suggested to me another important conclusion, one that he had missed: low-frequency, pulsing electrical fields could serve as sensory inputs to living organisms.

Hamer, Beischer, and I were looking for external fields that could influence behavior, while Delgado and others attacked the problem directly by electrically stimulating the brain. We all learned something. I believe that Delgado, no matter how one views his work, learned the most. Later, he continued with his work in such a fashion as to bring the two lines of investigation together.