José Delgado, implants, and electromagnetic mind control: Stopping the furious Bull

José Manuel Rodríguez Delgado (August 8, 1915 – September 15, 2011) was a Spanish professor of physiology at Yale University, famed for his research on mind control through electrical stimulation of the brain.


Delgrado used permanent brain implants to control behaviour. Later he utilised non-inversive methods.

  • José Manuel Rodríguez Delgado (1969). Physical Control of the Mind: Toward a Psychocivilized Society. Harper and Row. ISBN 978-0-06-090208-7.
  • Delgado JM (1977–1978). “Instrumentation, working hypotheses, and clinical aspects of neurostimulation”. Applied Neurophysiology. 40 (2–4): 88–110. 
  • Delgado, Jose M.; et al. Intracerebral Radio Stimulation and recording in Completely Free Patients, Journal of Nervous and Mental Disease, Vol 147(4), 1968, 329-340.
  • Delgado, José M.R. (1964). Free Behavior and Brain Stimulation. International Review of Neurobiology. 6. pp. 349–449. doi:10.1016/S0074-7742(08)60773-4.
Abstract - Free behaviour and brain stimulation (1964)
Of the methods used to investigate the neurophysiological basis of behavior, perhaps the most direct and dramatic is electrical stimulation of the brain. Direct stimulation of the brain is considered a crude method for the exploration of cerebral functions, and the understanding of the results is limited. The chapter describes methodology for cinemanalysis, telerecording, and telestimulation to study free behavior during brain stimulation. It also demonstrates that spontaneous activities are recorded, identified and quantified, allowing the systematic study of free and evoked behavior on both individual and social levels. The chapter also discusses the types and significance of behavior evoked by brain stimulation in unrestrained subjects and presents a theory of fragmental organization of behavior. Brain stimulation evokes (1) stereotyped tonic or phasic activity without any emotional disturbance, (2) driving activity to reach an objective with a motor performance adapted to the relations between subject and purpose, (3) changes in behavioral tuning that are detected in isolated animals because of the lack of manifestations, but may modify decisively the character of response to normal stimuli, (4) inhibition of spontaneous or evoked behavior, and (5) abnormal effects such as tremor or seizures.

Rodríguez Delgado’s research interests centered on the use of electrical signals to evoke responses in the brain. His earliest work was with cats, but he later did experiments with monkeys and humans, including psychiatric patients.[3][4]

Much of Rodríguez Delgado’s work was with an invention he called a stimoceiver, a radio which joined a stimulator of brain waves with a receiver which monitored E.E.G. waves and sent them back on separate radio channels. Some of these stimoceivers were as small as half-dollars. This allowed the subject of the experiment full freedom of movement while allowing the experimenter to control the experiment. This was a great improvement from his early equipment which included visual disturbance in those whose wires ran from the brain to bulky equipment that both recorded data and delivered the desired electrical charges to the brain. This early equipment, while not allowing for a free range of movement, was also the cause of infection in many subjects.[5]

The stimoceiver could be used to stimulate emotions and control behavior. According to Rodríguez Delgado, “Radio Stimulation of different points in the amygdala and hippocampus in the four patients produced a variety of effects, including pleasant sensations, elation, deep, thoughtful concentration, odd feelings, super relaxation, colored visions, and other responses.” Rodríguez Delgado stated that “brain transmitters can remain in a person’s head for life. The energy to activate the brain transmitter is transmitted by way of radio frequencies.”[6]

Using the stimoceiver, Rodríguez Delgado found that he could not only elicit emotions, but he could also elicit specific physical reactions. These specific physical reactions, such as the movement of a limb or the clenching of a fist, were achieved when Rodríguez Delgado stimulated the motor cortex. A human whose implants were stimulated to produce a reaction were unable to resist the reaction and so one patient said “I guess, doctor, that your electricity is stronger than my will”. Some consider one of Rodríguez Delgado‘s most promising finds is that of an area called the septum within the limbic region. This area, when stimulated by Rodríguez Delgado, produced feelings of strong euphoria. These euphoric feelings were sometimes strong enough to overcome physical pain and depression.[2]

Rodríguez Delgado created many inventions and was called a “technological wizard” by one of his Yale colleagues. Other than the stimoceiver, Rodríguez Delgado also created a “chemitrode” which was an implantable device that released controlled amounts of a drug into specific brain areas. Rodríguez Delgado also invented an early version of what is now a cardiac pacemaker.[2]

In Rhode Island, Rodríguez Delgado did some work at what is now a closed mental hospital. He chose patients who were “desperately ill patients whose disorders had resisted all previous treatments” and implanted electrodes in about 25 of them. Most of these patients were either schizophrenics or epileptics. To determine the best placement of electrodes within the human patients, Delgado initially looked to the work of Wilder Penfield, who studied epileptics’ brains in the 1930s, as well as earlier animal experiments, and studies of brain-damaged people.[2]

The most famous example of the stimoceiver in action occurred at a Córdoba bull breeding ranch. Rodríguez Delgado stepped into the ring with a bull which had had a stimoceiver implanted within its brain. The bull charged Delgado, who pressed a remote control button which caused the bull to stop its charge. Always one for theatrics, he taped this stunt and it can be seen today.[7] The region of the brain Rodríguez Delgado stimulated when he pressed the hand-held transmitter was the caudate nucleus. This region was chosen to be stimulated because the caudate nucleus is involved in controlling voluntary movements.[2] Rodríguez Delgado claimed that the stimulus caused the bull to lose its aggressive instinct.

Although the bull incident was widely mentioned in the popular media, Rodríguez Delgado believed that his experiment with a female chimpanzee named Paddy was more significant. Paddy was fitted with a stimoceiver linked to a computer that detected the brain signal called a spindle which was emitted by her part of the brain called the amygdala. When the spindle was recognized, the stimoceiver sent a signal to the central gray area of Paddy’s brain, producing an ‘aversive reaction’. In this case, the aversive reaction was an unpleasant or painful feeling. The result of the aversive reaction to the stimulus was a negative feedback to the brain.[2] Within hours her brain was producing fewer spindles as a result of the negative feedback.[8] As a result, Paddy became “quieter, less attentive and less motivated during behavioral testing”. Although Paddy’s reaction was not exactly ideal, Rodríguez Delgado hypothesized that the method used on Paddy could be used on others to stop panic attacks, seizures, and other disorders controlled by certain signals within the brain.[2] [9][10] Publication

José Rodríguez Delgado authored 134 scientific publications within two decades (1950-1970) on electrical stimulation on cats, monkeys and patients – psychotic and non-psychotic. In 1963, New York Times featured his experiments on their front page. Rodríguez Delgado had implanted a stimoceiver in the caudate nucleus of a fighting bull. He could stop the animal mid-way that would come running towards a waving red flag.[11]

He was invited to write his book Physical Control of the Mind: Toward a Psychocivilised Society as the forty-first volume in a series entitled World Perspectives edited by Ruth Nanda Anshen. In it Rodríguez Delgado has discussed how we have managed to tame and civilize our surrounding nature, arguing that now it was time to civilize our inner being. The book has been a centre of controversy since its release.[1] The tone of the book was challenging and the philosophical speculations went beyond the data. Its intent was to encourage less cruelty, and a more benevolent, happier, better man, however it clashed religious sentiments.

José Rodríguez Delgado continued to publish his research and philosophical ideas through articles and books for the next quarter century. He in all wrote over 500 articles and six books. His final book in 1989, was named Happiness and had 14 editions.

Delgado later learned he could duplicate the results he got with the stimoceiver without any implants at all, using only specific types of electromagnetic radiation interacting with the brain. He lamented he didn’t have access to the technology when Franco was in power, as it would have allowed him to control the dictator at a distance.





  • Elliot S. Valenstein (1973). Brain Control: A Critical Examination of Brain Stimulation and Psychosurgery. John Wiley & Sons. ISBN 978-0-471-89784-2.


Delgado, J. M. R.. (1970). SCIENCE AND HUMAN VALUES. Zygon®

Plain numerical DOI: 10.1111/j.1467-9744.1970.tb01129.x
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Blackwell, B.. (2012). Jose Manuel Rodriguez Delgado. Neuropsychopharmacology

Plain numerical DOI: 10.1038/npp.2012.160
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Delgado-García, J. M.. (2000). Why move the eyes if we can move the head?. Brain Research Bulletin

Plain numerical DOI: 10.1016/S0361-9230(00)00281-1
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Delgado-García, J. M.. (2001). Estructura y función del cerebelo. Revista de Neurologia
Wilder, J.. (2018). Physical Control of the Mind. Toward a Psychocivilized Society. American Journal of Psychotherapy

Plain numerical DOI: 10.1176/appi.psychotherapy.1971.25.3.485
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Molaee-Ardekani, B., Márquez-Ruiz, J., Merlet, I., Leal-Campanario, R., Gruart, A., Sánchez-Campusano, R., … Wendling, F.. (2013). Effects of transcranial Direct Current Stimulation (tDCS) on cortical activity: A computational modeling study. Brain Stimulation

Plain numerical DOI: 10.1016/j.brs.2011.12.006
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Delgado, J. M. R.. (1964). Free Behavior and Brain Stimulation. International Review of Neurobiology

Plain numerical DOI: 10.1016/S0074-7742(08)60773-4
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Delgado, J. M. R., Hamlin, H., & Chapman, W. P.. (1952). Technique of Intracranial Electrode Implacement for Recording and Stimulation and its Possible Therapeutic Value in Psychotic Patients. Stereotactic and Functional Neurosurgery

Plain numerical DOI: 10.1159/000105792
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Delgado-García, J. M., & Gruart, A.. (2005). Firing activities of identified posterior interpositus nucleus neurons during associative learning in behaving cats. Brain Research Reviews

Plain numerical DOI: 10.1016/j.brainresrev.2004.10.006
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Márquez-Ruiz, J., Ammann, C., Leal-Campanario, R., Ruffini, G., Gruart, A., & Delgado-García, J. M.. (2016). Synthetic tactile perception induced by transcranial alternating-current stimulation can substitute for natural sensory stimulus in behaving rabbits. Scientific Reports

Plain numerical DOI: 10.1038/srep19753
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