In 1963, Jose Delgado entered a bull-fighting ring in Cordova, Spain, along with a 500 kg heavy, angry bull. Delgado was not a matador and had never done anything like this before. Yet, he easily avoided the charging bull without even moving at all -just by pressing a button!



Dr. Jose Delgado of Yale University’s School of Medicine, had spent more than 15 years of his life before the bull-fight, researching the minds of animals, their response to electrical stimulation, and the biological and physiological underpinnings of behaviour and emotions. He had already started “playing” with other animals including monkeys and cats, as well as humans suffering from epilepsy. But his most impressive demonstration was arguably the bull-fighting event!

Delgado had implanted electrodes and a radio receiver (an invention he called a “stimoceiver“) in the bull’s brain the day before the fight. He then put his money where his mouth was and entered the ring himself to perform the ultimate test of his technology! At the press of a button in his radio transmitter, the raging bull came to a halt right in front of Delgado’s feet. At the press of a second button, the previously hot-tempered bull, turned around and left the scene!

Delgado continued his research on neurological disorders and neural stimulation as well as behaviour control -for which he developing an array of instruments including transdermal stimoceivers, brain radio stimulator devices and implantable microprocessors (see also [1]).

On the wake of Delgado’s experiment, many scientists and philosophers declared the end of dualism -the idea that the mind and material brain are two independent entities, based on this (and other related at the time experiments). Were they quick to have done so?

Already scientists knew that certain drugs could inhibit (or increase for what matters!) aggressive behaviour, swiftly manipulate emotions, and ultimately play a key role in the behaviour and mental state of individuals. Other clues were already coming from research on patients with some kind of brain damage who also demonstrated altered behaviour or lack of certain emotional “circuits”. Scientists have also long been able to indirectly stimulate and record the activity of nerve cells with the “old-fashioned” method of implanted electrodes -which nevertheless had many limitations.

Since then, the field of neuroscience has advanced rapidly -it is currently one of the hottest scientific areas. The “scientists of the brain” have:

• successfully mapped certain emotions and behaviours to certain circuits in the brain -using technologies such as functional MRI as well as fluorescent and genetically encoded dyes that reveal neural activity [2] [3]
  
  
• have associated certain mental disorders and neurological conditions to the dysfunction of specific brain areas or neuron pathways -very promising research that might lead to much better treatments for diseases such as Parkinson’s
  
  
• and have managed to manipulate behaviour and emotions by direct physical stimulation using apart from electrodes (like Delgado did back in the sixties) a more advanced array of tools that include light-sensitive genetically engineered actuators -proteins that trigger neural activity [4]. This type of actuators act like on-of switches for the specific type of circuitry that are attached. You turn the switch on: the animal is angry; you turn it off: the animal is relaxed again!

These advances, increasingly demonstrate that the material brain is indeed responsible for (and intimately coupled to) the mind, and presumably all the higher order cognitive processes that come pre-packaged with it -some of them unique to humans. It seems that (semi?) superstitious ideas, such as the existence of a soul separate from the body, and the existence of a mind independently of the physical brain, are being consistently pushed back by scientific advances to a point where they are relegated to something between wishful thinking, a bullet point in religious organizations recruitment brochures, and children’s bed-time stories.

What could, however, constitute conclusive evidence against the concept of dualism? One can claim that we still don’t have them -and indeed this seems to be the case. But the currently available body of evidence strongly suggests that the mind is simply an abstract entity “produced” by our material brains. Whatever the outcomes of neuroscientific research, it just promises to be fascinating -and perhaps, for some, worldview changing.

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References:

1. JM. Delgado, "Instrumentation, working hypotheses, and clinical aspects of neurostimulation," Applied Neurophysiology, 1977-1978, 40 (2-4), pp. 88-110. [↩]
2. MS. Siegel, EY. Isacoff, "A genetically encoded optical probe of membrane voltage," Neuron, 1997, 19, pp. 735–741 [↩]
3. BJ. Baker, H Mutoh, D Dimitrov, W. Akemann, A Perron, Y Iwamoto, L Jin, LB Cohen, EY Isacoff, VA Pieribone, T Hughes, T Knöpfel, "Genetically encoded fluorescent sensors of membrane potential," Brain Cell Biology, 2008, 36 (1-4), pp. 53-67 [↩]
4. S. Lima , G. Miesenböck, "Remote Control of Behavior through Genetically Targeted Photostimulation of Neurons," Cell, 121 (1), pp. 141-152 [↩]