Background

José Manuel Rodríguez Delgado (1915-2011) was a Spanish neuroscientist and professor of neurophysiology at Yale University who conducted controversial research on electrical stimulation of the brain. After receiving his Ph.D. from the Ramón y Cajal Institute in Madrid, Delgado joined Yale University’s physiology department in 1950, where he would conduct two decades of innovative research on the effects of direct electrical stimulation of brain tissue on behavior, emotion, and movement in animals and humans.

Key Contributions

Between 1950 and 1970, Delgado authored 134 scientific publications demonstrating that organized, complex behaviors in primates could be evoked and controlled through electrical stimulation of specific brain regions. His most famous experiment, conducted in 1963, involved implanting a “stimoceiver” (a device that could both stimulate neural tissue and record brain activity wirelessly) in a fighting bull’s caudate nucleus. When the bull charged at him in the bullring, Delgado was able to stop it instantly by pressing a handheld transmitter. Delgado presented the result as evidence that stimulation could inhibit aggression. University of Michigan neurophysiologist Elliot Valenstein disputed that reading, arguing that the stimulation had a purely motor effect that stopped the bull from charging straight ahead; Delgado stood by his interpretation. Delgado’s stimoceiver allowed freedom of movement for experimental subjects while maintaining experimental control.

Legacy

Delgado’s work, described in his 1969 book “Physical Control of the Mind: Toward a Psychocivilized Society,” is an early chapter in the history of electrical brain stimulation and raised ethical questions about the potential uses of brain stimulation technology. Delgado said he co-authored the first peer-reviewed paper describing deep brain stimulation in humans, in 1952. Modern deep brain stimulation (DBS) for Parkinson’s disease developed through later clinical work, notably by Alim Louis Benabid and Pierre Pollak in Grenoble from 1987, and Delgado’s papers are rarely cited by today’s researchers.