Dr. Robert G. Heath, a physician and medical researcher at Tulane University who was best known for his ground-breaking work on schizophrenia, died on Tuesday at his home in St. Petersburg, Fla. He was 84.

In 1957, Dr. Heath found a protein antibody called taraxein in the blood of schizophrenics that was capable of inducing schizophrenic-like symptoms in monkeys and healthy human volunteers.

The finding was controversial because it was early evidence that schizophrenia is of biochemical origin and not, as was widely believed at the time, related to childhood or other emotional traumas.

Dr. Heath also provided a footnote to investigations in the 1970's concerning the Central Intelligence Agency's use of private institutions in a secret effort to develop mind-control techniques.