Hartline, Haldan Keffer (1903-1983), an American physiologist (scientist who studies how living things function), made important discoveries about the structure of the eye and the working of the retina, the light sensitive part of the eye. For his discoveries, Hartline shared the 1967 Nobel Prize for physiology or medicine with fellow American George Wald, and Ragnar Granit from Sweden.
Much of Hartline’s research work centered on the retinas of simple animals, such as horseshoe crabs, and their electrical responses to light. In his horseshoe crab investigations, he was able to obtain a record of the electrical impulses transmitted by a single optic nerve fiber. Hartline also demonstrated that the receptors (cells sensitive to light) connected to the optic nerve fibre were so arranged that the stimulation of one receptor cell caused others nearby to become depressed. As a result, the contrast between different light patterns is heightened, and the ability to distinguish between different shapes is increased.
In the early 1940’s, Hartline conducted research on night vision in human beings. He also conducted important investigations into interactions among the cells of the retina.
Hartline was born in Bloomsburg in Pennsylvania. Hartline studied at Lafayette College, and at Johns Hopkins University in Baltimore, Maryland, as well as at the universities of Pennsylvania, Leipzig, and Munich. In 1949, he became professor of biophysics at Johns Hopkins and, in 1953, professor of neurophysiology at Rockefeller University in New York City.
