In the early 1970s Jose Manuel Rodriguez Delgado, a professor of physiology at Yale University, was among the world's most acclaimed--and controversial--neuroscientists. In 1970 the New York Times Magazine hailed him in a cover story as the "impassioned prophet of a new 'psychocivilized society' whose members would influence and alter their own mental functions." The article added, though, that some of Delgado's Yale colleagues saw "frightening potentials" in his work.

Delgado, after all, had pioneered that most unnerving of technologies, the brain chip--an electronic device that can manipulate the mind by receiving signals from and transmitting them to neurons. Long the McGuffins of science fiction, from The Terminal Man to The Matrix, brain chips are now being used or tested as treatments for epilepsy, Parkinson's disease, paralysis, blindness and other disorders. Decades ago Delgado carried out experiments that were more dramatic in some respects than anything being done today.